AudioCircle

Industry Circles => NuPrime Audio => Topic started by: kevb on 11 Nov 2015, 05:07 pm

Title: STA-9
Post by: kevb on 11 Nov 2015, 05:07 pm
Since there are now separate threads for the DAC-9 and HPA-9, I thought it might be useful to start a thread on the upcoming STA-9.  Rustydoglim has referred to some of the features and has graciously provided a link to some preliminary pictures in another thread so I am posting it here:

https://picasaweb.google.com/106836432394752820607/STA902

This amp does sound like it will be an excellent choice for those on a budget like myself.  I for one can't wait to see the finalized specifications!   :thumb:
Title: Re: STA-9
Post by: dr.sah on 5 Dec 2015, 10:08 am
I have ST-10 with DAC-10h, but I would like to have more power. Are two st-9 in monoblock more powerfull as single st-10?
Title: Re: STA-9
Post by: mresseguie on 5 Dec 2015, 02:40 pm
Dr.SAH,

Two STA-9s bridged will give you a stompingly powerful 290 watts per channel. That's a lot more than the ST-10's 150w.

Title: Re: STA-9
Post by: maty on 11 Dec 2015, 09:35 am
-> http://www.nuprimeaudio.com/index.php/products/amplifiers-and-preamps/stereo-amps/sta-9.html

Quote
Ultra-low distortion and noise

but

Quote
Signal to Noise Ratio: < -80dB at 1W, 10W, 100W

The two specifications may not be true at the same time!

Maybe the "SNR" is the Crosstalk.
Title: Re: STA-9
Post by: rustydoglim on 14 Dec 2015, 02:07 pm
I need to check again about this spec.
Title: Re: STA-9
Post by: Ozwel on 20 Dec 2015, 05:47 pm
Hi everyone,

I'm highly interested in a DAC-9 + 2 STA-9 setup.

If IDA-8 sounds warmer than IDA-16 because of the power amp and not the DAC, then should we deduct that DAC-9 + STA-9 will sound even warmer than ID-8 since both DAC and amp have their own warm signature?

Plus same question about the STA-9 SNR, weird figures since all the other amps are >100 :-)
Title: Re: STA-9
Post by: V-Fi on 2 Jan 2016, 10:50 pm

Plus same question about the STA-9 SNR, weird figures since all the other amps are >100 :-)

Me too. I think it must be typo or wrong label on that spec.
Title: Re: STA-9
Post by: rustydoglim on 8 Jan 2016, 02:59 pm
Engineer did the measurement and confirmed that SNR < -95dB
Title: Re: STA-9
Post by: mresseguie on 8 Jan 2016, 03:15 pm
Engineer did the measurement and confirmed that SNR < -95dB

Thank you for this. Now how does this number translate into our listening experience?

Is this something you wish you could sweep under the sofa, but it's too late?

What do you suppose would happen to the SNR after an upgrade by Bob at TDSS?

Thanks for any answers,

Michael
Title: Re: STA-9
Post by: V-Fi on 9 Jan 2016, 08:59 pm
Well Jason updated to 95dB which is not so bad at all. 80 dB is bad but 95 is fine. The highly regarded DDA-100 was around the same. Also it depends on how the measurement is done. Check out the specs on these Krell amps and see how the figures are very different depending on how they measure http://www.krellonline.com/stereo-amps.html
Title: Re: STA-9
Post by: Ozwel on 12 Jan 2016, 07:39 pm
I agree, 95db is good enough to forget about this spec.
Title: Re: STA-9
Post by: rustydoglim on 18 Jan 2016, 11:31 am
The numbers don't tell the whole story!!!
We added EVEN HARMONICS (the good harmonics) to the amp to make it sounded tube-like, but without the drawbacks of tube.
Obviously measurement can't tell the difference between noise or "texture"
Title: Re: STA-9
Post by: dr.sah on 29 Jan 2016, 05:54 am
2x STA-9 in bridge against ST-10 in sound quality? which combo would be better?   
Title: Re: STA-9
Post by: rustydoglim on 29 Jan 2016, 05:19 pm
Sound quality wise ST-10 is still better. But again, if you prefer more warmth, you might prefer STA-9.

See the amp comparison: http://www.nuprimeaudio.com/index.php/reviews/amp-comparison.html (http://www.nuprimeaudio.com/index.php/reviews/amp-comparison.html)
Title: Re: STA-9
Post by: Servingthemusic.com on 29 Jan 2016, 06:00 pm
I'm very interested in reviewing the STA-9. Is there a rep on here who can provide a sample?

Andre Marc
www.avrev.com
Title: Re: STA-9
Post by: dr.sah on 31 Jan 2016, 07:33 pm
Would be very sexy if you can make st-10 with bridge option.
Title: Re: STA-9
Post by: rustydoglim on 4 Feb 2016, 12:59 am
Would be very sexy if you can make st-10 with bridge option.

That is effectively MCH-K38.  ST-10 and the previous NuForce Ref series use a type of design that can not be bridged.
I wonder if you guys (who bought STA-9) discovered the transformation when it is bridged into mono.
Title: Re: STA-9
Post by: firedog on 4 Feb 2016, 07:09 am
Where on your scale would the STA-9's go as 2 mono amps vs an ST-10?
Title: Re: STA-9
Post by: pewe on 5 Feb 2016, 02:58 pm
Anyone got any pics from the inside of the STA-9?
Title: Re: STA-9
Post by: rustydoglim on 7 Feb 2016, 08:40 am
I will post a new topic on all the amps, internal photos, and update the amp comparison guide next week.
Title: Re: STA-9
Post by: maty on 7 Feb 2016, 10:12 am
I want naked!  8)

Thanks to the Nuprime ST-10 and the ferrites (speakers and RCA/XLR) inside:

(http://maty.galeon.com/WP-imagenes/hard/Nuprime-ST-10-inside.jpg) (http://maty.galeon.com/WP-imagenes/hard/Nuprime-ST-10-inside.jpg)

I decided to add a RFI Würth 150 kHz ferrite in my KEF Q100 monitors. First with the two cables and finally only the woofer cable, and I have better sound. I have to buy more ferrites to check for improvement in my others loudspeakers, and I will try with two ferrites too.

-> http://aficionados.foroactivo.com/t342p15-kef-q100-uni-q-bookshelf-speakers-5-25-coaxial-with-front-bass-reflex#16089 Spanish

To English:

-> https://translate.google.com/translate?sl=es&tl=en&js=y&prev=_t&hl=es&ie=UTF-8&u=http%3A%2F%2Faficionados.foroactivo.com%2Ft342p15-kef-q100-uni-q-bookshelf-speakers-5-25-coaxial-with-front-bass-reflex%2316089&edit-text=&act=url

(http://maty.galeon.com/WP-imagenes/kef-q100/KEF-Q100-crossover-Wurt-150-khz-ferrite.jpg)

Like you, I use more Schaffner RFI/EMI filters in my systems, but outside:

(http://maty.galeon.com/WP-imagenes/hard/cable-filtro-linea-schaffner-piezas.jpg)

to a friend:

(http://maty.galeon.com/WP-imagenes/hard/cables-Schaffner-filter-Wurth-ferrite-150Khz-IEC-C13-Schurter-from-ATL.jpg)
Title: Re: STA-9
Post by: maty on 20 Feb 2016, 01:57 pm
[Review] The NuPrime STA-9 Stereo Power Amplifier

-> http://totallywired.co.nz/nuprime_sta_9.html

Quote
This also leads to another scenario which is actually the best of all. The new NuPrime HPA-9 (http://www.nuprimeaudio.com/index.php/products/dacs-and-headphone-amps/headphone-amp/hpa-9.html) has dual outputs and this is partnered with a seriously capable analogue preamplifier section. This is where you find out just how capable the STA-9 is - the improvement in dynamics and overall goodness is quite remarkable. At this point I think yes - this is at the same level as the ST-10 (http://www.nuprimeaudio.com/index.php/products/amplifiers-and-preamps/stereo-amps/st-10.html). You have more power and the benefits of separating bass and treble and also two power supplies. This makes up for some specification advantages in the bigger amplifier and provides a fantastic listening experience. Given the extra cabling, you'll end up at about the same end cost as an ST-10 but what this does enable is an upgrade path (which is quite likely to be improved upon as time goes on).

So - in summary - if you start with a NuPrime STA-9 power amplifier in any scenario, you can progressively upgrade like this.

1. STA-9
2. Second STA-9 added, switch both to bridged mode
3. Add a second set of speaker cables and interconnects, switch back to normal mode and bi-amp
4. Add a high quality preamplifier.

Question: Has HPA-9 a remote control?
Title: Re: STA-9
Post by: rustydoglim on 20 Feb 2016, 07:32 pm
HPA-9 does not have a remote.
Title: Re: STA-9
Post by: ChuckT on 1 Mar 2016, 02:23 pm
I want naked!  8)

Thanks to the Nuprime ST-10 and the ferrites (speakers and RCA/XLR) inside:

(http://maty.galeon.com/WP-imagenes/hard/Nuprime-ST-10-inside.jpg) (http://maty.galeon.com/WP-imagenes/hard/Nuprime-ST-10-inside.jpg)

I decided to add a RFI Würth 150 kHz ferrite in my KEF Q100 monitors. First with the two cables and finally only the woofer cable, and I have better sound. I have to buy more ferrites to check for improvement in my others loudspeakers, and I will try with two ferrites too.

-> http://aficionados.foroactivo.com/t342p15-kef-q100-uni-q-bookshelf-speakers-5-25-coaxial-with-front-bass-reflex#16089 Spanish

To English:

-> https://translate.google.com/translate?sl=es&tl=en&js=y&prev=_t&hl=es&ie=UTF-8&u=http%3A%2F%2Faficionados.foroactivo.com%2Ft342p15-kef-q100-uni-q-bookshelf-speakers-5-25-coaxial-with-front-bass-reflex%2316089&edit-text=&act=url

(http://maty.galeon.com/WP-imagenes/kef-q100/KEF-Q100-crossover-Wurt-150-khz-ferrite.jpg)

Like you, I use more Schaffner RFI/EMI filters in my systems, but outside:

(http://maty.galeon.com/WP-imagenes/hard/cable-filtro-linea-schaffner-piezas.jpg)

to a friend:

(http://maty.galeon.com/WP-imagenes/hard/cables-Schaffner-filter-Wurth-ferrite-150Khz-IEC-C13-Schurter-from-ATL.jpg)

Why do you need to add another RFI/EMI to you electrical input, as you can see, there is already one inside the ST-10?
I also found it odd that you can improve the sound by adding such a high frequency inductor to you speaker. 150khz is really out of the audio range.
Title: Re: STA-9
Post by: ChuckT on 1 Mar 2016, 02:25 pm
HPA-9 does not have a remote.
Could you please please post an inside photo of the STA-9 and Dac-9. Thanks.
Title: Re: STA-9
Post by: maty on 1 Mar 2016, 03:09 pm
Because I have a terrible mains: a lot of ripple, RF/EMI and up to 3 Vdc!!!! And RFI/EMI in the air too.

Fed up with poor sound quality decided to investigate and gradually have been finding solutions.

-> http://aficionados.foroactivo.com/t197-usb-isolator-ifi-iusb-vs-teradak-u9va-teralink-adum4160-filtros-schaffner-lampizator-ac-filter-diy-esa-silk-estabilizador-regulador-de-tension-voltaje-isolation-balanced-transformer-dc-blocker-blocking-pc-silencioso-en-aussar-variac

To English -> https://translate.google.com/translate?sl=es&tl=en&js=y&prev=_t&hl=es&ie=UTF-8&u=http%3A%2F%2Faficionados.foroactivo.com%2Ft197-usb-isolator-ifi-iusb-vs-teradak-u9va-teralink-adum4160-filtros-schaffner-lampizator-ac-filter-diy-esa-silk-estabilizador-regulador-de-tension-voltaje-isolation-balanced-transformer-dc-blocker-blocking-pc-silencioso-en-aussar-variac&edit-text=

Quote
My second system.

RFI/EMI Schaffner filters + Würth 150 kHz ferrites (power and RCA cables) and DC & Ripple Blocker to ALL SYSTEM.

I have:

1 Shaffner + 1 Würth ferrite => Power Strip => DC & Ripple Blocker (4 outputs, in star) =>

=> 1 Schaffner -> AV Marantz SR 4500

=> ifi iCAN

=> 1 Schaffner -> PC (with Bequiet! L8 400 PSU: 5mV/10mV ripple in 5V – USB)

1 Schaffner + 1 Würth 150 kHz -> old 17″ Hitachi CRT monitor (1998), with very good image!

PC => 1 Würth 150 kHz (two rounds) in cheap USB cable -> ODAC =>

ODAC -> RCA cable with 2 Würth 150 kHz ferrites -> ifi iCAN

ODAC -> RCA cable with 2 Würth 150 kHz ferrites -> AV Marantz SR4500

And now, in my KEF Q100 speakers, a Würth 150 kHz ferrite ONLY in woofer cable.

Then add in the rest of the house until the maximum attenuation without loss of dynamic.

Three Würth 150 kHz 8 mm ferrite = One RFI/EMI Schaffner FN9244 3A filter, in attenuation.
Title: "Lowering OUT of band noise contributed to sound quality improvement..."
Post by: maty on 1 Mar 2016, 03:16 pm
"I also found it odd that you can improve the sound by adding such a high frequency inductor to you speaker. 150khz is really out of the audio range."

(http://maty.galeon.com/WP-imagenes/kef-q100/KEF-Q100-filter-rockwool.jpg)

-> http://aficionados.foroactivo.com/t197p225-usb-isolator-ifi-iusb-vs-teradak-u9va-teralink-adum4160-filtros-schaffner-lampizator-ac-filter-diy-esa-silk-estabilizador-regulador-de-tension-voltaje-isolation-balanced-transformer-dc-blocker-blocking-pc-silencioso-en-aussar-variac#16147

-> -> http://www.absolutesound.com.sg/media-features/why-did-teac-use-the-ak4490-dac-in-the-ud-503/

(http://www.absolutesound.com.sg/wp-content/uploads/2016/02/OUTOFBANDNOISE.jpg)

Quote
Lowering OUT of band noise contributed to sound quality improvement. In the graph above, the blue section indicates the values of DACs manufactured by another company, and the pink section indicates values of DAC made by AKM...

Würth 150 kHz ferrites and RFI/EMI Schaffner filters to attenuate OUT of band noise too!

DC Blocker x2, x4 with BIG EPCOS: to attenuate IN of band (audio) noise, aka ripple.
Title: ATL Hi-Fi DC & Ripple Blocker x4 ME
Post by: maty on 1 Mar 2016, 03:18 pm
ATL Hi-Fi DC & Ripple Blocker x4 ME

-> http://aficionados.foroactivo.com/t197p195-usb-isolator-ifi-iusb-vs-teradak-u9va-teralink-adum4160-filtros-schaffner-lampizator-ac-filter-diy-esa-silk-estabilizador-regulador-de-tension-voltaje-isolation-balanced-transformer-dc-blocker-blocking-pc-silencioso-en-aussar-variac#15777

(http://maty.galeon.com/WP-imagenes/hum/ATL-Hi-Fi-DC-Blocker-x4-ME-open-front-side.jpg)

I ask for forgiveness so off topic in this thread.
Title: Re: STA-9
Post by: rustydoglim on 4 Mar 2016, 10:07 am
Good info. You're very welcome.
Title: Re: STA-9
Post by: KLH007 on 13 Mar 2016, 04:23 pm
Sound quality wise ST-10 is still better. But again, if you prefer more warmth, you might prefer STA-9.

See the amp comparison: http://www.nuprimeaudio.com/index.php/reviews/amp-comparison.html (http://www.nuprimeaudio.com/index.php/reviews/amp-comparison.html)

That chart still has the ST-10 sounding cooler than an IDA-16?
Title: Re: STA-9
Post by: mresseguie on 13 Mar 2016, 04:30 pm
That chart still has the ST-10 sounding cooler than an IDA-16?

That's not how I read the chart. The ST-10 and the IDA-16 are in the same cell. At the top of the chart is the line "Models that are in the same cell are ranked the same." Therefore, they are ranked the same. Rustydog could just as easily have placed the ST-10 above the IDA-16 in that cell with no change in meaning, no?
Title: Re: STA-9
Post by: KLH007 on 13 Mar 2016, 06:19 pm
That's not how I read the chart. The ST-10 and the IDA-16 are in the same cell. At the top of the chart is the line "Models that are in the same cell are ranked the same." Therefore, they are ranked the same. Rustydog could just as easily have placed the ST-10 above the IDA-16 in that cell with no change in meaning, no?

You are correct, but in his other comments he places the ST-10 somewhere between the IDA-8 and IDA-16, not in the same category? Having heard them both, I hear the ST-10 as less lean compared to the IDA-16. The standard of "neutral" is being skewed toward what many, including me, would call threadbare or harmonically leached, IMHO.
Title: Re: STA-9
Post by: mresseguie on 14 Mar 2016, 01:27 am
You are correct, but in his other comments he places the ST-10 somewhere between the IDA-8 and IDA-16, not in the same category? Having heard them both, I hear the ST-10 as less lean compared to the IDA-16. The standard of "neutral" is being skewed toward what many, including me, would call threadbare or harmonically leached, IMHO.

For clarity, you have heard both ST-10 and IDA-16(?), or IDA-8 and IDA-16? [still waking up/no coffee yet]

With luck and, perhaps, a little begging I hope to audition the ST-10 [Edit: (or possibly dual STA-9s)] in my system in another 5 weeks or so. I've been curious about the ST-10 for several months now.
Title: Re: STA-9
Post by: KLH007 on 14 Mar 2016, 03:56 pm
For clarity, you have heard both ST-10 and IDA-16(?), or IDA-8 and IDA-16? [still waking up/no coffee yet]

With luck and, perhaps, a little begging I hope to audition the ST-10 (or possibly dual STA-8s) in my system in another 5 weeks or so. I've been curious about the ST-10 for several months now.

I have not heard the IDA-8, but I have listened to the IDA-16 and ST-10, as well as the Bob Smith ST-10 SE mod. I'm listening to the overachieving pair of STA-9 & DAC-9 currently. Ranking the amps, in comparison to each other, the IDA-16 is on the cooler side, STA-9 warmer, and ST-10 in the middle. The differences are small but discernable, and since the NuPrime engineers can "dial in" the amount of warmth (add even harmonics ) as mentioned in this thread, you can choose your own desired temperature. I will say that if you don't find the Sabre chip DACs to be your cup of tea, the DAC-9 is a perfect foil, less incisive, yet still detailed, allowing less than perfectly recorded music very enjoyable, and a real bargain. Paired with the STA-9, they are doing a superb job in my system, great values can be found in High End audio.
Title: Re: STA-9
Post by: mresseguie on 14 Mar 2016, 04:19 pm
007KLH,

How would you characterize the differences between the stock ST-10 and the modded ST-10?

I was curious enough about those mods that I contacted Bob recently about my possibly modding a component. It's still a consideration.

Michael
Title: Re: STA-9
Post by: KLH007 on 14 Mar 2016, 10:24 pm
007KLH,

How would you characterize the differences between the stock ST-10 and the modded ST-10?

I was curious enough about those mods that I contacted Bob recently about my possibly modding a component. It's still a consideration.

Michael

Michael, I have heard the SE, but not made any comparisons to any other amps. At the Mini CAF in Rockville, a cold and thrown together system with LaScala, AQUA pre, ST-10 SE, Dana cables (new & no burn in), and GT Audio Works GTA 2.5 speakers, after 2 hours the system began to sing, but no other amps were put into the system before breakdown. I hope to have a chance to compare the SE to a Wells Akasha soon. Call or email Mark Sossa at Well pleased A/V more more impressions about the ST-10 SE.
Title: Re: STA-9
Post by: JackD on 15 Mar 2016, 12:36 am
Michael I have the IDA-8 and also the DAC-10/ST-10 combo. To me their sonic signatures are pretty different.  The 8 is definately on the warm side, while I find the 10 combo to pretty neutral.  My source who has had all three in the same system said that the 16 was more to the lean side than the 10.  The 9 is supposed to be between the 8 and 10.  I had found a great deal on an "as new" 16 and was considering it until the lean description came up which I later confirmed with another owner.  An interesting combo might be the DAC-9 and ST-10.  Like Kemper said talk to Mark at Well Pleased as he has tried most of the Nuprime combos in his system.
Title: Re: STA-9
Post by: KLH007 on 15 Mar 2016, 02:21 am
Michael I have the IDA-8 and also the DAC-10/ST-10 combo. To me their sonic signatures are pretty different.  The 8 is definately on the warm side, while I find the 10 combo to pretty neutral.  My source who has had all three in the same system said that the 16 was more to the lean side than the 10.  The 9 is supposed to be between the 8 and 10.  I had found a great deal on an "as new" 16 and was considering it until the lean description came up which I later confirmed with another owner.  An interesting combo might be the DAC-9 and ST-10.  Like Kemper said talk to Mark at Well Pleased as he has tried most of the Nuprime combos in his system.

Jack, For many the bang for the buck combo is as you mentioned, DAC-9/ST-10, synergistic duo.
Title: Re: STA-9
Post by: JackD on 15 Mar 2016, 02:27 am
As of what's playing now, the DAC-10/ST-10 on the Odyssey Lorelei's is a pretty killer combo.  I may soon take Mark up on his offer to try the DAC-9 and compare it to the DAC-10 and the La Voce. When the weather warms up some more here in balmy North Florida the ST-10 will go to the main room with the Nola KO's, Modwright LS-100 and the La Voce and the mAMPS will go back in with the DAC-10.
Title: Re: STA-9
Post by: duke of dorkdom on 17 Apr 2016, 05:08 pm
Curious why power does "double down"
Title: Re: STA-9
Post by: duke of dorkdom on 17 Apr 2016, 05:12 pm
edit: "Curious why power does NOT "double down""
Title: Re: STA-9
Post by: rustydoglim on 17 Apr 2016, 08:08 pm
Curious why power does "double down"

What do you mean?
Title: Re: STA-9
Post by: KLH007 on 18 Apr 2016, 01:33 pm
I think the "Duke" is asking why the power output doesn't double into 4 ohm loads, instead of being the same as 8 ohm level?
Title: Re: STA-9
Post by: duke of dorkdom on 19 Apr 2016, 12:02 pm
correct. A power rating that stays the same while the load impedance is lowered is, to me, unusual outside of tubes. Not a knock or anything, just honestly curious why this is. Was it by design?
Title: Re: STA-9
Post by: roscoeiii on 19 Apr 2016, 02:43 pm
correct. A power rating that stays the same while the load impedance is lowered is, to me, unusual outside of tubes. Not a knock or anything, just honestly curious why this is. Was it by design?

IIRC, and I am not a technical science guy, but Class D (or just some Class D) does not double down (or increase as a Class A or A/B amp would) into 4 Ohms.
Title: Re: STA-9
Post by: rustydoglim on 20 Apr 2016, 06:53 pm
This question was asked in another topic and I am sure it will come up. Here's the answer that non tech person can understand
http://www.nuprimeaudio.com/index.php/reviews/faq.html#faq_18 (http://www.nuprimeaudio.com/index.php/reviews/faq.html#faq_18)

In short, it doesn't double down is because 1) we are conservative in our spec and 2) the power supply is the limiting factor, nothing to do with the amp.  More power = more cost also (amp also has to scale up) = bigger amp = NOT IDA-8 anymore :)
Title: Re: STA-9
Post by: larsg on 21 Apr 2016, 11:06 am
Tried to use 2 STA-9 in bridged mono but the volume level was not equal on both. How to match volume level ??
Title: Re: STA-9
Post by: John Casler on 22 Apr 2016, 05:28 am
Tried to use 2 STA-9 in bridged mono but the volume level was not equal on both. How to match volume level ??

Hi Lars,

Sure that is not normal, so something is either not working correctly, the system is not hooked up correctly, or a source or preamp issue is causing it.

To see if it is an amp issue, simply reverse the L&R channels and if it switches to the other amp the issue is not amp related.

If it does stay with one of the amps, then check all amp connections and bridging switches are set correctly.

And it goes without saying, but if you are using an RCA on one channel and an XLR on the other, the XLR will be louder and the RCA softer, but you already knew this.

Title: Re: STA-9
Post by: larsg on 22 Apr 2016, 07:31 am
Tried all you mention and it,s down to the Amps. It,s not a big difference but enough to irritate.
Title: Re: STA-9
Post by: rustydoglim on 22 Apr 2016, 09:58 pm
Did you try to use a Decible Meter app (there are free apps) or the smartphone to measure the sound level ?
If they are measured differently, we can fix or exchange for you.
Title: Re: STA-9
Post by: larsg on 23 Apr 2016, 04:23 pm
It was 5 Db diffrence between the two STA-9
Pink noise , HPA-9 , RCA too STA-9 in mono mode. Ran the test tree times on STA-9 Nr. 1 , plugged it out and plugged Nr. 2 inn and ran the test 3 times again without toutching anyting. Nr. 1 69/70 Db Nr. 2 74/75 Db everytime.
Title: Re: STA-9
Post by: Armaegis on 23 Apr 2016, 06:53 pm
A 6dB difference is a rather common gain setting difference and also corresponds to a double/half voltage. It also corresponds to the typical difference between balanced/unbalanced signals. Are all the switches set correctly at the back?
Title: Re: STA-9
Post by: larsg on 23 Apr 2016, 09:56 pm
All the switches was set correctly. But as a last try I moved the mono switch up and down many times and finally it "clicked" in place and both STA-9 was at 74/75 Db.
Never gonna touch it again !!
Kenwood KD-64F + HPA-9 + ST-10 + JBL 4312E on second floor.
Panasonic TV + IDA-8 + Tannoy Mercury V1i in living room.
PC + DAC-10 + 2 x STA-9 + Pro-Ject CD-player + Audiovector SR3 AA in my mancave.

(http://www.audiocircle.com/image.php?id=141814)
Title: Re: STA-9
Post by: KLH007 on 23 Apr 2016, 10:01 pm
Where are you hiding the second STA-9?
Title: Re: STA-9
Post by: KLH007 on 23 Apr 2016, 10:02 pm
Is it black and barely visible?
Title: Re: STA-9
Post by: larsg on 23 Apr 2016, 10:04 pm
Silver for right and black for left  :D
Title: Re: STA-9
Post by: Armaegis on 23 Apr 2016, 10:36 pm
All the switches was set correctly. But as a last try I moved the mono switch up and down many times and finally it "clicked" in place and both STA-9 was at 74/75 Db.
Never gonna touch it again !!

Hey awesome that it worked out. I had a feeling that was the most likely culprit.
Title: Re: STA-9
Post by: John Casler on 24 Apr 2016, 12:37 am
Silver for right and black for left  :D

That's the problem, SILVER is "always" louder than Black. . . .just kidding of course.

Do check that switch and make sure it is tight and secure.

There is a little nut that tightens it up to the chassis.  I had one that worked itself slightly loose,

Glad to hear the issue is actually resolved for you.
Title: Re: STA-9
Post by: drumnman2 on 25 Apr 2016, 12:15 pm
Please let us know if you feel going to 2 mono amps improve the sound quality. I have been enjoying an sta 9 for a few months and am considering doing the same.
Title: Re: STA-9
Post by: duke of dorkdom on 25 Apr 2016, 01:52 pm
In short, it doesn't double down is because 1) we are conservative in our spec and 2) the power supply is the limiting factor, nothing to do with the amp.  More power = more cost also (amp also has to scale up) = bigger amp = NOT IDA-8 anymore :)

Okay, that makes sense. Also opens door to future upgrades (external beefier PS) which is cool.

Got another question:
I like how you can "design" your sound switching in different pieces of the 9 and 10 series. If I understand correctly, having both pre/DAC and power amp being 10s is the closest to neutral and using both 9s is the warmest. Where does DAC10 with one STA9, DAC10 with two STA9s, and DAC9 with ST10, all rest on the spectrum?
Title: Re: STA-9
Post by: rustydoglim on 25 Apr 2016, 02:21 pm
The warmer component will always influence the sound.
Amp will have more influence on the sound characteristic then DAC.

So, by the above logic, going from most neutral to warmth will be
DAC-10 + ST-10
DAC-10 + STA-9
DAC-9 + STA-9

Keep in mind that any among of coloration is due to addition of even order harmonics which no doubt will increase the noise floor. You can't say I want the warmth but I still want my -130db noise floor. 
Title: Re: STA-9
Post by: John Casler on 25 Apr 2016, 11:32 pm
The warmer component will always influence the sound.
Amp will have more influence on the sound characteristic then DAC.

So, by the above logic, going from most neutral to warmth will be
DAC-10 + ST-10
DAC-10 + STA-9
DAC-9 + STA-9

Keep in mind that any among of coloration is due to addition of even order harmonics which no doubt will increase the noise floor. You can't say I want the warmth but I still want my -130db noise floor.

This is EXCELLENT advice and information.

I might also comment on a couple things.

First:  I am under the impression that even order harmonics are often measured as "noise" or distortions.  So don't let that fool you into thinking the STA-9, or the MCH K-38 are "noisy".  Even though the specs might suggest higher noise, in operation you notice nothing of the sort.

Second: Regarding "tube like" sound of the AMPS = Please know, that in the case of these amps, tube like "does not" mean syrupy, lacking highs, lacking transparency, lacking bass, etc.

I have recently spent a LOT of time listening to the MCH K-38 in bridged mode, running a 2 channel system (currently just turning off the other channels)

The results are ASTONISHING!!!

I will soon post some of my findings, and some of you may think me "over the top", but what I am hearing is so far beyond impressive, that GIANT KILLER is not even close to an adequate description.

And Rustydoglim's assessment of mixing and matching is SPOT ON.

If you have edgy aggressive speakers, the DAC-9/STA-9 are for you.

If your speakers are less than sparkly, the DAC-10/ST-10 will light your fire.

Title: Re: STA-9
Post by: rustydoglim on 26 Apr 2016, 04:07 pm
MCH-K38 is a beast!
Title: Re: STA-9
Post by: mresseguie on 26 Apr 2016, 05:08 pm
This is EXCELLENT advice and information.

I might also comment on a couple things.

First:  I am under the impression that even order harmonics are often measured as "noise" or distortions.  So don't let that fool you into thinking the STA-9, or the MCH K-38 are "noisy".  Even though the specs might suggest higher noise, in operation you notice nothing of the sort.

Second: Regarding "tube like" sound of the AMPS = Please know, that in the case of these amps, tube like "does not" mean syrupy, lacking highs, lacking transparency, lacking bass, etc.

I have recently spent a LOT of time listening to the MCH K-38 in bridged mode, running a 2 channel system (currently just turning off the other channels)

The results are ASTONISHING!!!

I will soon post some of my findings, and some of you may think me "over the top", but what I am hearing is so far beyond impressive, that GIANT KILLER is not even close to an adequate description.

And Rustydoglim's assessment of mixing and matching is SPOT ON.

If you have edgy aggressive speakers, the DAC-9/STA-9 are for you.

If your speakers are less than sparkly, the DAC-10/ST-10 will light your fire.

John,

This Friday when I show up to audition gear, you're going to get either support from me or a splash of cold water. LOL!

We're in Crescent City checking out the Coast Redwoods till tomorrow or Wednesday. See you Friday afternoon. The ST-10 and DAC-10 made it through the night safely.

Correct me if I'm wrong, there is a switch on the DAC-10 that toggles between brighter/more forward and more laid back, yes? Alan mentioned it after his GTG, but I haven't verified this.

Michael
Title: Re: STA-9
Post by: John Casler on 26 Apr 2016, 11:17 pm
John,

This Friday when I show up to audition gear, you're going to get either support from me or a splash of cold water. LOL!

We're in Crescent City checking out the Coast Redwoods till tomorrow or Wednesday. See you Friday afternoon. The ST-10 and DAC-10 made it through the night safely.

Correct me if I'm wrong, there is a switch on the DAC-10 that toggles between brighter/more forward and more laid back, yes? Alan mentioned it after his GTG, but I haven't verified this.

Michael

Hi Michael,

It will depend on how good your ears and listening skills are, and your listening preferences.

So hot. warm and cold water are all good. :) 

The adjustment on the DAC-10 is for "high output" and "low output" for both the preamp section, and the headphone section.

It actually doesn't change the sound or accuracy.  It changes the voltage output from 2v to 4v on RCA, and 4v to 8v on XLR.
Title: Re: STA-9
Post by: mresseguie on 27 Apr 2016, 02:14 am
John,

Under what circumstances would a person desire to use the high output or low output setting?
Title: Re: STA-9
Post by: JackD on 27 Apr 2016, 02:46 am
Michael

The low setting is based on the industry standard of 2 volts and 4 volts.  I don't know what purpose the high setting would serve as I have never had the urge to try it.  I don't have nor have I ever had an amp whose input sensitivity was that bad.  I'm sure Jason's people had something in mind.
Title: Re: STA-9
Post by: rustydoglim on 28 Apr 2016, 06:01 pm
It is mainly for the headphone amp.
Title: Re: STA-9
Post by: John Casler on 28 Apr 2016, 06:21 pm
Michael

The low setting is based on the industry standard of 2 volts and 4 volts.  I don't know what purpose the high setting would serve as I have never had the urge to try it.  I don't have nor have I ever had an amp whose input sensitivity was that bad.  I'm sure Jason's people had something in mind.

As per Rustydoglim, the primary function is for the headphones, but I have used both on the preamp side and prefer the higher output.

That said, one might also find the lower outputs more favorable to very high efficiency speakers, which are so sensitive as to amplify noise in the chain.

That then would also hold true that for less efficient speakers maybe having a benefit from the HIGH setting.

But do keep in mind, that 2v RCA and 4v XLR is basically normal output.
Title: Re: STA-9
Post by: kevb on 29 Apr 2016, 11:59 am
Just bought the STA-9 to try it out in my main system.  Right now the only point of reference for power amps that I have to compare it to is a DIY (Rawson) amp and a pair of Crown XLS2500's.  If I like what I hear from the STA-9, I will probably pick up a second one to run as monoblocks in bridged mode.

I also have the IDA-8 here (still love it as much as when I first bought it), and a couple of other integrateds (Jungson, Jolida)

I will post my impressions on the STA-9 here after spending some time with it.
Title: Re: STA-9
Post by: drumnman2 on 6 May 2016, 12:13 pm
Please let us know if you feel going to 2 mono amps improve the sound quality. I have been enjoying an sta 9 for a few months and am considering doing the same.
 

Anyone ???
Title: Re: STA-9
Post by: John Casler on 6 May 2016, 08:16 pm
 

Anyone ???

Yes, and far more than just upping the power.

Bridging does "some kind of magic" to the STA-9 and K-38 amps.

Check out the specs, even the distortion "halves"  :thumb:  In most amp designs, it would DOUBLE!!!

Very soon, I will be reporting on what I have found about the STA-9 and K-38.

GIANT KILLER doesn't come close to describing the Sonic Qualities of these amps when bridged. 

Try it, you'll like it (as long as your gear, room, and hearing will allow you to hear it. :green:
Title: Re: STA-9
Post by: kbouldk on 8 May 2016, 12:34 pm
Yes, and far more than just upping the power.

Bridging does "some kind of magic" to the STA-9 and K-38 amps.

Check out the specs, even the distortion "halves"  :thumb:  In most amp designs, it would DOUBLE!!!

Very soon, I will be reporting on what I have found about the STA-9 and K-38.

GIANT KILLER doesn't come close to describing the Sonic Qualities of these amps when bridged. 

Try it, you'll like it (as long as your gear, room, and hearing will allow you to hear it. :green:

Can't wait to read your report. Had a STA9/DAC9 for little more than a week now. Love it!
Being the person I am, I already started dreaming about this upgrade.
Of course it would have to do more than just looking great, but it will look fantastic on the table top under the TV, in line with the DAC in the middle.
I don't need it louder as it already plays very loud. Bit worried about the speakers thogh - they are only 140W, so it could be a dangerous setup?
Title: Re: STA-9
Post by: Eisener Bart on 12 May 2016, 10:27 pm
Hmm,

STA-9 gives more warm sound - it looks like a good choice in my case.

The question is:

if I will take 2 pcs of STA-9, how can use it for bi-amping? I mean - 1 stereo amp for 1 speaker.
I removed original interconnect between 2 pairs of connectors of my speakers about 1 month ago when I could buy a piece of same speaker cable (Acoustic Revive - SPC Reference). Thus I am feeding now 2 speakers from 1 stereo amp using bi-wiring.

I have only 1 XLR output on my AMR DP-777. I can't use RCA output simultaneously, it will be too long from Rack to speakers. Output voltage from XLR is more than 2 V. No data regarding anything else.   

Title: Re: STA-9
Post by: rustydoglim on 13 May 2016, 06:09 am
I think in general, a more powerful and better sounding amp will always be better than bi-amping (cost of cables and amps). And bi-wiring has questionable improvement. Therefore

Quote
if I will take 2 pcs of STA-9, how can use it for bi-amping? I mean - 1 stereo amp for 1 speaker.
Configure STA-9 in mono mode instead of using the stereo amp for bi-amping.  The product page went into design details about why mono mode actually sounded better, besides offering a staggering 290W RMS power.


Quote
I removed original interconnect between 2 pairs of connectors of my speakers about 1 month ago when I could buy a piece of same speaker cable (Acoustic Revive - SPC Reference). Thus I am feeding now 2 speakers from 1 stereo amp using bi-wiring.

See above. With two STA-9 amps, you can compare bi-amping versus mono amps.

Quote
I have only 1 XLR output on my AMR DP-777. I can't use RCA output simultaneously, it will be too long from Rack to speakers. Output voltage from XLR is more than 2 V. No data regarding anything else.   

Just go with mono amps on each side.
Title: Re: STA-9
Post by: Eisener Bart on 13 May 2016, 07:41 am
I think in general, a more powerful and better sounding amp will always be better than bi-amping (cost of cables and amps). And bi-wiring has questionable improvement.

In my case is better.

Configure STA-9 in mono mode instead of using the stereo amp for bi-amping.  The product page went into design details about why mono mode actually sounded better, besides offering a staggering 290W RMS power.
Obviously.

See above. With two STA-9 amps, you can compare bi-amping versus mono amps.

Just go with mono amps on each side.

I want to arrange 4 amping channels for 2 speakers.
1 mono block for 1 speaker - in this case I have put back original interconnector, which I don't like.
SPC Reference works better than original silver wire.

How I will drive by 4 channels if 1 have only 1 pair of XLR output?
Title: Re: STA-9
Post by: rustydoglim on 13 May 2016, 08:57 am
Custom order is another possibility.  We are planning to offer NuPrime Custom Audio as an extension of the retail products. It is not meant to be a replacement but complementary offering.
This is a good case for our factory and engineering to figure out.
We want to be able to let customer drive multiple amps (either using MCH-K38 or an array of STA-9) for music listening or commercial installation, without compromising the sound quality.
Title: Re: STA-9
Post by: Eisener Bart on 13 May 2016, 09:15 am
Custom order is another possibility.  We are planning to offer NuPrime Custom Audio as an extension of the retail products. It is not meant to be a replacement but complementary offering.
This is a good case for our factory and engineering to figure out.
We want to be able to let customer drive multiple amps (either using MCH-K38 or an array of STA-9) for music listening or commercial installation, without compromising the sound quality.

I have opportunity to upgrade my balance cable matter to drive 4 channels using only 1 pair of XLR output.
I got consultation today from one person but I wanna get advices from 2 other engineers.

Output voltage definitely from AMR DP-777 should be enough to drive 4 amping channels.
Title: Re: STA-9
Post by: Armaegis on 13 May 2016, 10:21 pm
Eisener: what speakers are you attempting to drive? The way you're describing things doesn't quite add up. Are you still amping into the internal speaker crossover?

Output voltage shouldn't matter at all when driving multiple channels. Voltage is not split between the two amps.
Title: Re: STA-9
Post by: Eisener Bart on 14 May 2016, 11:57 am
Output voltage shouldn't matter at all when driving multiple channels. Voltage is not split between the two amps.
Yeah, you are right. I meant enough current.

My Speakers are Audio Physic Avanti.
Title: Re: STA-9
Post by: Armaegis on 14 May 2016, 08:54 pm
Yeah, you are right. I meant enough current.

My Speakers are Audio Physic Avanti.

The current should be inconsequential. Any amp input impedance should be very high; even if you had a dozen of them chained together, you're still in the milliamp range.

I think the benefits of bi-amping here are going to be squashed because you're ultimately driving the crossovers, not the speakers. As Jason mentioned, you'd probably be better off running a bridged amp in mono (for higher quality power, rather than simply "more") on each side and don't fuss with the bi-amping.

In my opinion, to truly benefit from bi-amping in the way that you're thinking, you will want to bypass the internal crossover entirely. This requires an active crossover setup, which comes *before* the amps. I do this regularly with my PA setups using a Behringer DCX2496.
Title: Re: STA-9
Post by: Dadbeh on 14 May 2016, 09:15 pm
so if
The current should be inconsequential. Any amp input impedance should be very high; even if you had a dozen of them chained together, you're still in the milliamp range.

I think the benefits of bi-amping here are going to be squashed because you're ultimately driving the crossovers, not the speakers. As Jason mentioned, you'd probably be better off running a bridged amp in mono (for higher quality power, rather than simply "more") on each side and don't fuss with the bi-amping.

In my opinion, to truly benefit from bi-amping in the way that you're thinking, you will want to bypass the internal crossover entirely. This requires an active crossover setup, which comes *before* the amps. I do this regularly with my PA setups using a Behringer DCX2496.

so if someone has a computer as the source and the a DAC directly driving the amp, then where would this activecrossover go? I imagine you are talking about a solution like miniDSP? then it would have to go before the DAC, right?

and if so then you need 3 DACs for the 3 way system? im probably missing something
Title: Re: STA-9
Post by: Armaegis on 14 May 2016, 10:04 pm
If you use a miniDSP and output separate digital signals, then yes you would need dacs downstream of each.

My use of the word "active" above was a bit of a flub; you could still use a passive crossover after the dac to split the stream, and you would feed these new channels directly to your amps.

In my case, my DCX2496 performs both crossover and DAC duties. Actually, when I feed it two analog channels from a mixer: it does the ADC conversion first, handles all the hoopla digitally, then does DAC duties again and spits out 6 channels.
Title: Re: STA-9
Post by: rustydoglim on 15 May 2016, 08:11 am
The direct driving of speaker drivers is an expensive solution and also depending on the components to output band limiting frequencies (high freq to tweeter, mid and low to woofer if it is two way).  A well designed cross-over can do a good job so I think before anyone make such attempt, you should review the FR plot of your speaker.
Title: Nuprime STA-9 inside
Post by: maty on 15 May 2016, 09:13 am
-> http://www.audionet.com.tw/a/thread-8356-1-1.html

(http://maty.galeon.com/WP-imagenes/hard/Nuprime-STA-9-inside.jpg) (http://maty.galeon.com/WP-imagenes/hard/Nuprime-STA-9-inside.jpg)

Title: Nuprime IDA-8 inside
Post by: maty on 15 May 2016, 09:16 am
-> http://www.feversound1.com/nuprime-ida8/

(http://maty.galeon.com/WP-imagenes/hard/Nuprime-IDA-8-inside.jpg) (http://maty.galeon.com/WP-imagenes/hard/Nuprime-IDA-8-inside.jpg)
Title: Re: STA-9
Post by: Nidri17 on 15 May 2016, 09:36 am
Wonder why the board inside the STA-9 has writing that says 'IDA-8'?
Is the amp module the same?
Title: Re: STA-9
Post by: rustydoglim on 15 May 2016, 03:37 pm
The power stage board is the same but the "preamp" stage is different. The preamp stage in STA-9 makes it "tube-like" sounding.
See the illustrative diagram on the product pages for STA-9 and IDA-8.
As I have said, we are an engineering company, what you see is what you get  :thumb:
Title: Re: STA-9
Post by: maty on 15 May 2016, 04:10 pm
The STA-9 toroid is bigger.

And the BIG capacitors are... 105 ºC, surprising in this price range, which speaks highly of the manufacturer.

Title: Re: STA-9
Post by: Eric Gustafsson on 26 May 2016, 06:30 am
STA-9 used as monoblocks is a giant killer. I've never heard a better amp regardless of price.  :thumb:
Title: Re: STA-9
Post by: hk29 on 27 May 2016, 02:10 am
STA-9 used as monoblocks is a giant killer. I've never heard a better amp regardless of price.  :thumb:

Oh don't tell me that!  :)  I'm deciding between the ST-10 vs. STA-9 monoblocks.  I wish there was a store I could listen to them.  Its a tough decision based on reading it.  From what I've read: STA-9 Mono (warm, dynamic) vs. ST-10 (resolution).  Its a tough trade-off for me....

Does bridging the STA-9 change the sound quality in any way (besides higher power)?
Title: Re: STA-9
Post by: larsg on 27 May 2016, 06:09 am
Switched  between 2 STA-9 and ST-10 for some weeks now, 3 days STA-9 3 days ST-10 ++
ST-10 got that little extra for me.
Title: Re: STA-9
Post by: Eric Gustafsson on 27 May 2016, 11:13 am
I discovered Yesterday that STA-9 needs a realy good preamp to perform at top.
My passive preamp from Hattor Audio makes STA-9 become a star.
Title: Re: STA-9
Post by: rustydoglim on 28 May 2016, 09:09 pm
The HPA-9 is a very good preamp for STA-9 if you don't want to use a DAC as preamp.
Title: Re: STA-9
Post by: Eisener Bart on 16 Jun 2016, 08:32 pm
I will get STA-9 for testing tomorrow.  :no_see:
Title: Re: STA-9
Post by: Nidri17 on 16 Jun 2016, 08:42 pm
Switched  between 2 STA-9 and ST-10 for some weeks now, 3 days STA-9 3 days ST-10 ++
ST-10 got that little extra for me.

I have the ST-10 (and DAC-9) and I'm very happy with the sound.
But I'm very curious about the 'warmth' of the STA-9 that a lot of people refer to.
Like I said, I'm happy, but I could be even happier perhaps?
Title: Re: STA-9
Post by: rustydoglim on 16 Jun 2016, 10:57 pm
See the Amp Comparison chart. You have the ST-10 and going with STA-9, you will give up something on the ST-10  :nono:
Title: Re: STA-9
Post by: Eisener Bart on 17 Jun 2016, 05:41 pm
Well.  :D

(http://f20.ifotki.info/org/86235830e87f87f11487f6b0e42a9b122eafa3248845282.jpg) (http://i-fotki.info/)

(http://f20.ifotki.info/org/0e768ec9f9dd0692bca8a3953e51c2dd2eafa3248845303.jpg) (http://i-fotki.info/)
Title: Re: STA-9
Post by: rustydoglim on 17 Jun 2016, 06:08 pm
 :duh: :duh: :duh:
You are not using our original feet
 :evil: :evil: :evil:
Title: Re: STA-9
Post by: Eisener Bart on 17 Jun 2016, 06:14 pm
:duh: :duh: :duh:
You are not using our original feet
 :evil: :evil: :evil:

I am using my own production. And I can bet that it's better.  :green:
Title: Re: STA-9
Post by: Eisener Bart on 17 Jun 2016, 06:19 pm
:duh: :duh: :duh:
You are not using our original feet
 :evil: :evil: :evil:

And I am not using stock original power cable too.  :D
Title: Re: STA-9
Post by: audioguy213 on 17 Jun 2016, 06:35 pm
how does it sound?
Does it justify the fancy feet and PC?
Title: Re: STA-9
Post by: mresseguie on 17 Jun 2016, 06:39 pm
:duh: :duh: :duh:
You are not using our original feet
 :evil: :evil: :evil:

 :rotflmao:

Poor Jason.

If you send me all your different amps to audition, I promise to use only stock feet and stock power cords.  8) 8) 8)
Title: Re: STA-9
Post by: Eisener Bart on 17 Jun 2016, 06:59 pm
how does it sound?
Does it justify the fancy feet and PC?

I connected Power Amp to my System only 7 hours ago.
Too early for serious talks regarding Sound.

First impression - very positive. My System's Power Amp (T+A, model A1500) smokes bamboo.
But as I can hear - all symptoms of unburned device. So I plan to continue preparation.
Unfortunately my dealer gave it to me only for few days.
I am feeling great Tempation now.  :scratch:

I have already 2 remarks if Jason will be interesting, I can share it. Nothing serious by the way.

Re footers and Power Cable: 1) my first footers I made in December 2010. Since that time I didn't keep in hands
serious competitors fot my production. And - no, it's not just some kind of rubber.  8) 2) Power Cable - I am using for STA-9 top NeoTech cable. It's NEP-3001 MK3 3x5.25 OCC/SPUPOCC hybrid power cable with NeoTech NC-P303 OCC EU power plug Gold connectors. This combination showed excellent result with my Power Amp T+A. I don't see any sense to spent time in vain compairing with stock cable.
Title: Re: STA-9
Post by: Eisener Bart on 17 Jun 2016, 07:09 pm
Cultural shock.

That's what I am feeling now.
It's second amp wtih Class D technology in my life.

(http://f20.ifotki.info/org/3e5ab742da3d229b2ce246e5b60213302eafa3248850596.jpg) (http://i-fotki.info/)
Title: Re: STA-9
Post by: Armaegis on 17 Jun 2016, 07:18 pm
At one point I was using cut up egg cartons for my feet, lol.
Title: Re: STA-9
Post by: Eisener Bart on 18 Jun 2016, 09:30 am
At one point I was using cut up egg cartons for my feet, lol.

Any audiophile passed hard times in life.  :green:
Title: Better sound with a power cable => problems with RFI/EMI
Post by: maty on 18 Jun 2016, 09:44 am
2) Power Cable - I am using for STA-9 top NeoTech cable. It's NEP-3001 MK3 3x5.25 OCC/SPUPOCC hybrid power cable with NeoTech NC-P303 OCC EU power plug Gold connectors. This combination showed excellent result with my Power Amp T+A. I don't see any sense to spent time in vain compairing with stock cable.

One day I wanted to check for myself, spending as little as possible (I was very skeptical, by academic training).

[Spanish] https://nauscopio.wordpress.com/2013/07/24/cable-de-redalimentacion-de-haiviech-netzkabel-ultimative-silber-mit-kupfer-silberkontakten/

To English -> https://translate.google.com/translate?sl=es&tl=en&js=y&prev=_t&hl=es&ie=UTF-8&u=https%3A%2F%2Fnauscopio.wordpress.com%2F2013%2F07%2F24%2Fcable-de-redalimentacion-de-haiviech-netzkabel-ultimative-silber-mit-kupfer-silberkontakten%2F&edit-text=

The improvement was there, I could not deny. Then I started a long learning process and I concluded that improvement was produced by RFI / EMI attenuation so I decided it was better and cheaper to use professional solutions to solve my problem.

Schaffner RFI/EMI filters first and then with Würth 150 kHz ferrites too.
Title: Re: STA-9
Post by: Eisener Bart on 18 Jun 2016, 11:55 am
On Peter Gabriel 2002 "Up" I never heard such bass from my speakers.   :thumb:
Title: Re: STA-9
Post by: Armaegis on 18 Jun 2016, 04:07 pm
Any audiophile passed hard times in life.  :green:
Well before that it was a cut up toilet paper roll... but switched to the egg cartons for aesthetics  :lol:


Actually the whole thing was because the mono amps were running hot and I needed more space between them when stacked.
Title: Re: STA-9
Post by: Eisener Bart on 18 Jun 2016, 04:13 pm
I have plan to come on US market with my footers etc.  :green:
Title: Re: STA-9
Post by: Eric Gustafsson on 20 Jun 2016, 05:52 am
A couple of days ago I changed from using my STA-9 as monoblocks to use them in a bi-amp setup. The sound is much better, but I miss the extra power from the monoblock connection. So now I plan to buy two more STA-9. The idea is to use all four as monoblocks - two for each channel.
Any one here who has tried that and can give some feedback?
Title: Re: STA-9
Post by: mresseguie on 20 Jun 2016, 06:05 am
Eric,

Considering the cost of four STA-9 amps, have you considered trading up to a single Nuprime K-38 amp? Talk to John or Jason about this idea. I suspect you'd be floored by what it can do.

Michael
Title: Re: STA-9
Post by: Eisener Bart on 20 Jun 2016, 09:36 am
A couple of days ago I changed from using my STA-9 as monoblocks to use them in a bi-amp setup. The sound is much better, but I miss the extra power from the monoblock connection. So now I plan to buy two more STA-9. The idea is to use all four as monoblocks - two for each channel.
Any one here who has tried that and can give some feedback?

That's what I'm thinking now - 4 monoblocks in prospects.

What Pre Amp will you use to drive 4 channels?
Title: Re: STA-9
Post by: Eric Gustafsson on 20 Jun 2016, 06:19 pm
Eric,

Considering the cost of four STA-9 amps, have you considered trading up to a single Nuprime K-38 amp? Talk to John or Jason about this idea. I suspect you'd be floored by what it can do.

Michael

It has crossed my mind to go for a K-38, but still four STA-9 is cheaper then one K-38. At least here in Sweden.
Title: Re: STA-9
Post by: Eric Gustafsson on 20 Jun 2016, 06:23 pm
That's what I'm thinking now - 4 monoblocks in prospects.

What Pre Amp will you use to drive 4 channels?

The preamp is from Hattor Audio in Poland. www.hattor.com
It's a passive preamp with a separate tube active stage.
Title: Re: STA-9
Post by: Eisener Bart on 20 Jun 2016, 08:30 pm
The preamp is from Hattor Audio in Poland. www.hattor.com
It's a passive preamp with a separate tube active stage.

Thank you! It's not for me, I need XLR outputs. For the moment I put my eye on 2 models - McIntosh C52 and Ayre KX-5 Twenty.
Title: Re: STA-9
Post by: Eisener Bart on 20 Jun 2016, 08:31 pm
It has crossed my mind to go for a K-38, but still four STA-9 is cheaper then one K-38. At least here in Sweden.

yeah, but don't forget about 3 extra Power Cable.
Title: Re: STA-9
Post by: opnly bafld on 20 Jun 2016, 09:45 pm
The preamp is from Hattor Audio in Poland. www.hattor.com
It's a passive preamp with a separate tube active stage.


Thank you! It's not for me, I need XLR outputs. For the moment I put my eye on 2 models - McIntosh C52 and Ayre KX-5 Twenty.

The Hattor passive is available with XLR in and out.
Title: Re: STA-9
Post by: Eric Gustafsson on 21 Jun 2016, 05:31 am
Thank you! It's not for me, I need XLR outputs. For the moment I put my eye on 2 models - McIntosh C52 and Ayre KX-5 Twenty.

You can order the preamp with XLR-outputs.
Title: Re: STA-9
Post by: Eric Gustafsson on 21 Jun 2016, 05:34 am
yeah, but don't forget about 3 extra Power Cable.

I will have four indepent power supplies instead of one common.
Title: Re: STA-9
Post by: Eisener Bart on 21 Jun 2016, 11:29 am
I will have four indepent power supplies instead of one common.

My air condition is connected to same wall socket as STA-9. Amp is whistling when AC is on.
So I'm also thinking about some regenerators.
Title: Re: STA-9
Post by: maty on 21 Jun 2016, 02:00 pm
Air conditioned -> add DC at mains. If your amp has a big toroidal (500VA or more)... hum and hot.

I have "tons" of DC (up to incredible 2.8Vdc - 50 Hz/230Vac in Spain) and RFI/EMI in my house but now I have resolved the problem  :D

The regenerators add more noise. And the power conditioners do not have a DC blocker (only is optional in one model).

Trust me, before buying expensive devices first you must solve your problems with power mains.
Title: Re: STA-9
Post by: Eisener Bart on 21 Jun 2016, 04:28 pm
I'm waiting second STA-9 but for the moment no date of delivery.
Title: Re: STA-9
Post by: Eisener Bart on 21 Jun 2016, 04:38 pm
You can order the preamp with XLR-outputs.

Eric, how will you describe Hattor Pre Amp for transparency?
Which model do you have?
Title: Re: STA-9
Post by: Eric Gustafsson on 23 Jun 2016, 08:52 pm
Eric, how will you describe Hattor Pre Amp for transparency?
Which model do you have?
In my opinion the Hattor pre amp is open and transperant.
I have the "cheapest" version.

Title: Re: STA-9
Post by: Eric Gustafsson on 24 Jun 2016, 04:46 pm
Is it ok to place one STA-9 on top of another STA-9?
No risk the items get to hot?
Title: Re: STA-9
Post by: Eisener Bart on 24 Jun 2016, 05:02 pm
Is it ok to place one STA-9 on top of another STA-9?
No risk the items get to hot?

Don't stack one on another one, footers will be melted and then Jason will punish you on public.  :rotflmao:

If seriously - not good idea. It's rather hot.

by the way - I will get tomorrow second STA-9.  :D
Title: Re: STA-9
Post by: Eric Gustafsson on 24 Jun 2016, 05:24 pm


by the way - I will get tomorrow second STA-9.  :D

Looking forward to hear about it.
Will you use them as mono blocks or biamp?
Title: Re: STA-9
Post by: Eisener Bart on 24 Jun 2016, 05:32 pm
Looking forward to hear about it.
Will you use them as mono blocks or biamp?

For bi-amping I will need 4 amps. It will be overkill, my dealer will commit suicide.  :green:

To be clear - I took it for test and reviewing only.

Monoblocks. I tried to switch it on with 1 amp. It has great prospects, no doubts.
Title: Re: STA-9
Post by: Eric Gustafsson on 24 Jun 2016, 05:33 pm
Don't stack one on another one, footers will be melted and then Jason will punish you on public.  :rotflmao:


I also thought about melted footers, but then I found this picture at www.nuprime.com.

(http://www.nuprimeaudio.com/media/rokgallery/e/e4c56d55-7040-46d4-91b4-ae128146529f/HPA-9-lifestyle4.jpg)

Title: Re: STA-9
Post by: Eric Gustafsson on 24 Jun 2016, 05:36 pm
For bi-amping I will need 4 amps. It will be overkill, my dealer will commit suicide.  :green:

To be clear - I took it for test and reviewing only.

Monoblocks. I tried to switch it on with 1 amp. It has great prospects, no doubts.

You can biamp them with just two units. The sound is amazing!
Title: Re: STA-9
Post by: Eisener Bart on 24 Jun 2016, 05:49 pm
You can biamp them with just two units. The sound is amazing!

That's what I will do tomorrow.

I already started to jump on my coach from sit position. Coach also should be prepared for tomorrow's Act of Revellation. My neighbors still don't suspect anything.  :violin: :drums: :banana piano:

Actually I could control 4 channels from my AMR DP-777 but I need to resolder XLR connectors from his side.
Title: Re: STA-9
Post by: Eric Gustafsson on 24 Jun 2016, 05:59 pm
For bi-amping I will need 4 amps. It will be overkill, my dealer will commit suicide.  :green:

I don't get it.
First you say you need 4 amps for bi-amping and now you will bi-amp with 2 amps. Did I misunderstand you?  :o
Title: Re: STA-9
Post by: Eisener Bart on 24 Jun 2016, 06:04 pm
I don't get it.
First you say you need 4 amps for bi-amping and now you will bi-amp with 2 amps. Did I misunderstand you?  :o

We didn't understand each other.

I will connect 2 bridged amps to 2 speakers. By 1 pair of speaker cables.
Title: Re: STA-9
Post by: Eric Gustafsson on 24 Jun 2016, 08:54 pm
We didn't understand each other.

I will connect 2 bridged amps to 2 speakers. By 1 pair of speaker cables.

Edit: Double post.
Title: Re: STA-9
Post by: Eric Gustafsson on 24 Jun 2016, 09:11 pm
We didn't understand each other.

I will connect 2 bridged amps to 2 speakers. By 1 pair of speaker cables.

As far as I know you can't have a bi-amp connection with 2 bridged STA-9. If you use bridged STA-9 you need 4 of them to have a bi-amp connection.
Title: Re: STA-9
Post by: Eisener Bart on 25 Jun 2016, 02:31 pm
It bravely passed through the dark night from capital city towards South.   :green:

(http://f20.ifotki.info/org/2277bae8c0a08a7453f4f4137b01d30e2eafa3249524890.jpg) (http://i-fotki.info/)
Title: Re: STA-9
Post by: Eisener Bart on 25 Jun 2016, 02:32 pm
Twins are ready for job.

(http://f20.ifotki.info/org/3adeeb7d6dc8fa3fab8853c77de28ef82eafa3249524922.jpg) (http://i-fotki.info/)
Title: Re: STA-9
Post by: Armaegis on 25 Jun 2016, 06:10 pm
What are those little stringy wires coming out of the back?
Title: Re: STA-9
Post by: Eisener Bart on 25 Jun 2016, 06:38 pm
What are those little stringy wires coming out of the back?

It's wire leading to harmonizer. You may see on photo (right side of Rack).

(http://f20.ifotki.info/org/5ed75d06ce9139260663e664adc287b22eafa3242848750.jpg) (http://i-fotki.info/)

Title: Re: STA-9
Post by: Armaegis on 25 Jun 2016, 07:45 pm
That... inverted pyramid thing?
Title: Re: STA-9
Post by: audioguy213 on 25 Jun 2016, 07:56 pm
That... inverted pyramid thing?

reduces EMI/RFI from Alien transmissions

(http://www.audiocircle.com/image.php?id=145571)

(this is meant in good fun, my own pyramid hat runs on beeswax fuses and a 60V battery)
Title: Re: STA-9
Post by: srb on 25 Jun 2016, 08:10 pm
I avoid hanging antennas off of my equipment unless it's attached to a tuner to specifically to pull in radio or television transmissions.  If I need harmonization I provide that with my vocal chords (to the best of my ability).
Title: Re: STA-9
Post by: bummrush on 25 Jun 2016, 08:10 pm
 What a nice clean setup
Title: Re: STA-9
Post by: Eisener Bart on 25 Jun 2016, 08:30 pm
That... inverted pyramid thing?

It works. I don't care how much crazy it looks.

If add this thing ( https://www.acoustic-revive.com/english/roomtuning/rr-77.html ) - will be much better.
Title: Re: STA-9
Post by: Eisener Bart on 25 Jun 2016, 08:30 pm
What a nice clean setup

Thank you.
Title: Re: STA-9
Post by: Eisener Bart on 25 Jun 2016, 10:35 pm
For the moment sound of 2 STA-9 in bridged mode I like less than sound of 1 STA-9 in stereo mode.

2 reasons:

1. STA-9 in stereo mode was feeded by top Power Cable of NeoTech brand.
For 2 bridged amps I have to use 2 Power Cable (self-made) which are absolutely identical.

2. 1 amp I received only yesterday, condition - "from box".

Of course I can hear difference anyhow. 2 monoblocks have crazy dynamic, more control, I can listen music
on very low volume's level, LF is deeper.
(http://f20.ifotki.info/org/00f3b980b97106f8f49b1dbe5492cf622eafa3249554095.jpg) (http://i-fotki.info/)

(http://f20.ifotki.info/org/23dc29e2880236b8e2af921226c417c42eafa3249554139.jpg) (http://i-fotki.info/)


Title: Re: STA-9
Post by: Eisener Bart on 26 Jun 2016, 11:06 am
2 pcs STA-9 in bridged mode with my self-made Power Cables sound more ... tuby in LF band.
Title: Re: STA-9
Post by: Eisener Bart on 26 Jun 2016, 01:24 pm
1 more strange thing - I switched on air condition today. No whistling in right channel.
Title: Re: STA-9
Post by: audioguy213 on 26 Jun 2016, 03:56 pm
What are your speakers?
4 or 8 ohm?
thanks


Are you using Audio Physic Avanti 89db @4ohm?

I heard that the bridged ST-9 was not so happy with 4 ohm loads, any words on that?
Title: Re: STA-9
Post by: Eisener Bart on 26 Jun 2016, 04:03 pm
What are your speakers?
4 or 8 ohm?
thanks

Audio Physic
Avanti (first model, 1990)
86 dB
4 Ohm.
Title: Re: STA-9
Post by: Eisener Bart on 26 Jun 2016, 04:04 pm

I heard that the bridged ST-9 was not so happy with 4 ohm loads, any words on that?

It's not true.  :D



Title: Re: STA-9
Post by: rustydoglim on 26 Jun 2016, 05:56 pm
Amazing where these "I heard that ..." came from.
By the way, it is STA-9, not ST-9.
Title: Re: STA-9
Post by: Eisener Bart on 26 Jun 2016, 05:59 pm
I guess if I will install 4 STA-9, I can hear everything on whisper volume level.  :green:
Title: Re: STA-9
Post by: John Casler on 26 Jun 2016, 06:02 pm
I guess if I will install 4 STA-9, I can hear everything on whisper volume level.  :green:

Or for an additional $400 you can go with the K-38 for 400wpc x 4  :thumb:

Title: Re: STA-9
Post by: Eisener Bart on 26 Jun 2016, 06:06 pm
Or for an additional $400 you can go with the K-38 for 400wpc x 4  :thumb:

I am already tied to explain - I can not keep ANY amp between my speakers. My Rack stays on left side, NOT between speakers. I need only mono blocks.
Title: Re: STA-9
Post by: dwaleke on 26 Jun 2016, 06:09 pm
I am already tied to explain - I can not keep ANY amp between my speakers. My Rack stays on left side, NOT between speakers. I need only mono blocks.

Then put a single amp in your rack on the left side and nothing between your speakers.  Does the K38 not fit in your rack?
Title: Re: STA-9
Post by: Eric Gustafsson on 26 Jun 2016, 06:28 pm
I guess if I will install 4 STA-9, I can hear everything on whisper volume level.  :green:

That will be my next step, 4 STA-9. The sound of 2 STA-9 running in bridged mood sounds fantastic. Looking forward to have 4 STA-9.  :drool:
Title: Re: STA-9
Post by: Eisener Bart on 26 Jun 2016, 06:32 pm
Red Cross near the Window - place where I kept Power Amp T+A. First problem - restriction with access to window.
Second problem - all these wires around Power Amp looks not good. Third problem - my youngest daughter used to jump
over the speakers' wires.

My idea - to hide even XLR cable to right channel under the baseboard.

Light green zone near the Window doesn't accept ANY large object. Soundstage ceases from degradation.

(http://f20.ifotki.info/org/f26ff8ace713d6be772ea53986d7ddcf2eafa3249625561.jpg) (http://i-fotki.info/)
Title: Re: STA-9
Post by: Eisener Bart on 26 Jun 2016, 06:38 pm
That will be my next step, 4 STA-9. The sound of 2 STA-9 running in bridged mood sounds fantastic. Looking forward to have 4 STA-9.  :drool:

It will be nice to read your conclusion about quadro-amping. What are your speakers?
Title: Re: STA-9
Post by: Eric Gustafsson on 26 Jun 2016, 07:10 pm
It will be nice to read your conclusion about quadro-amping. What are your speakers?
Magnepan 3.3/R
Title: Re: STA-9
Post by: Eisener Bart on 27 Jun 2016, 10:51 am
Eric, I found that temperature of STA-9 in bridged mode much less than in stereo.
I think you may stack 2 pcs.
Title: Re: STA-9
Post by: Eric Gustafsson on 27 Jun 2016, 12:44 pm
Eric, I found that temperature of STA-9 in bridged mode much less than in stereo.
I think you may stack 2 pcs.
Thanks, that was interesting.
Title: Re: STA-9
Post by: Eisener Bart on 27 Jun 2016, 06:23 pm
Eric, did you try to feed by 1 STA-9 in stereo mode - 1 speaker?
Actually it looks like quadro-amping.
If yes - what is impression?
Title: Re: STA-9
Post by: Eric Gustafsson on 27 Jun 2016, 10:33 pm
Eric, did you try to feed by 1 STA-9 in stereo mode - 1 speaker?
Actually it looks like quadro-amping.
If yes - what is impression?
I have had each STA-9 in stereo mode. One connected to the tweeter/midrange on both speakers an the other to the bass on both speaker.
The sound is very good, but the speakers needs more power to deliver at top.
When I will have 4 STA-9 they will run in bridged mode. One will feed the tweeter/midrange at the right channel and one the tweeter/midrange at the left channel. The other two will feed the bass in the same way.
Title: Re: STA-9
Post by: srb on 27 Jun 2016, 10:55 pm
I have had each STA-9 in stereo mode. One connected to the tweeter/midrange on both speakers an the other to the bass on both speaker.

That's called horizontal bi-amping.  Usually vertical bi-amping is more efficient using one stereo amp with L and R channels feeding mid/high and bass on one speaker.  That's usually a more efficient way of distributing power as you don't have two bass panels (which consume much more power than the mid/high) loading down one stereo amplifier.

Often horizontal bi-amping is used when employing different amplifiers for sonic and operational reasons, i.e. a tube amp for the mid/high for it's sonic signature and a solid state amp for control and low impedance operation on the bass.

So it's a bit puzzling that you said "but the speakers needs more power to deliver at top" because your horizontal configuration should have given you all the power you need for the mid/high and the bass should have been the ones lacking power.

I guess it will be a moot point with 4 mono amps.

Steve
Title: Re: STA-9
Post by: Eisener Bart on 27 Jun 2016, 11:55 pm
I guess it will be a moot point with 4 mono amps.


Why if he will send 290Wts x 4 instead of 120 Wts x 4 ???
Title: Re: STA-9
Post by: srb on 28 Jun 2016, 12:03 am
Why if he will send 290Wts x 4 instead of 120 Wts x 4 ???

Exactly.  I'm saying the debate / comparison of whether horizontal vs. vertical bi-amping is better with two stereo amps in his scenario will be rendered moot (a non-issue) with 4 bridged amps.

Steve
Title: Re: STA-9
Post by: Eric Gustafsson on 28 Jun 2016, 12:19 pm
Thanks Steve for the information about the different types of bi-amping.
 I didn't know about vertical bi-amping. I will try it right away.
Title: Re: STA-9
Post by: Eisener Bart on 28 Jun 2016, 12:31 pm
Thanks Steve for the information about the different types of bi-amping.
 I didn't know about vertical bi-amping. I will try it right away.

It's exactly what I've asked you a few posts above.
Very interesting!  :P
Title: Re: STA-9
Post by: Eric Gustafsson on 28 Jun 2016, 12:42 pm
Now I have tried vertical bi-amping and I didn't like it at all. The music became to much laid back for me. I also had to turn up the volume control.
So now I'm back to bridged mode and I like that much more.
Title: Re: STA-9
Post by: srb on 28 Jun 2016, 02:33 pm
So now I'm back to bridged mode and I like that much more.

I've tried passive bi-amping several times, and always ended up preferring a single more powerful amplifier channel as well.  One time I had a 5 channel amplifier (125W x 5), and 2 of channels were just sitting there unused so I bi-amped the main speakers, and it that case it was a little bit better than not using them at all.

But going to a more powerful 200W + amplifier was better yet than the lower power bi-amp setup.  The more powerful amplifier had more reserves and dynamic power to give the speaker what it needed when it needed it.

So that's my personal experience with passive bi-amping.  If you have extra channels of amplification lying around (and the amplifier cannot be bridged) what the heck, go for it.  But if you can bridge the amps or are able to replace them with a more powerful amplifier, 4 times out of 5 you'll probably be happier with the results.

BTW, many bridgeable amplifiers when bridged can't deal with lower impedance 4 ohm (or less) speakers as the bridged amp often sees half the impedance (2 ohms or less).  Apparently the NuPrime amplifiers don't have this limitation.

Active bi-amping with an active line level crossover (bypassing the speaker's internal passive crossover) does have a lot more potential, but that also comes with additional expense and complexity.

Steve
Title: Re: STA-9
Post by: Jg107 on 9 Jul 2016, 10:22 pm
Hello all,  I just stumbled onto the Nuprime threads last night for the first time and read a lot of posts that has caught my attention :thumb:.  I was wondering how hot these (or ST-10) get idling and under load.  I'm currently using an Adcom GFA 5800 (114* idle) with a Denon receiver (100* idle) and it gets pretty toasty in my small room.
Title: Re: STA-9
Post by: jonbee on 10 Jul 2016, 12:04 am
Hello all,  I just stumbled onto the Nuprime threads last night for the first time and read a lot of posts that has caught my attention :thumb:.  I was wondering how hot these (or ST-10) get idling and under load.  I'm currently using an Adcom GFA 5800 (114* idle) with a Denon receiver (100* idle) and it gets pretty toasty in my small room.
I have an ST-10, and it gets just a little warm at idle, and it doesn't change much under load (85% efficient). Nowhere near the heat of what you're using.
Title: Re: STA-9
Post by: Jg107 on 10 Jul 2016, 01:44 am
I have an ST-10, and it gets just a little warm at idle, and it doesn't change much under load (85% efficient). Nowhere near the heat of what you're using.

Thank you very much!  I'm new to the hobby and learning everyday.  Until yesterday my short list of amplifiers were Hypex based amplifiers,  the Acoustic Imagery Atsah 500 and the NAD M22.  I have decided to purchase a Parasound P5 preamp,  hopefully it would match nicely with any of these amplifiers.  Now I have to decide on the ST-10 and STA-9(s) as well   :lol: 
Title: Re: STA-9
Post by: JackD on 10 Jul 2016, 03:50 am
jg107

A little more info about your system would be helpful before giving advice but absent of that I would stick with the ST-10.  It is a higher level and more developed product.  I own the ST-10, DAC-10 and the IDA-8 (which is supposed to be voiced similar to the STA-9)  If that is in fact the case the ST-10 is a far more flexible and resolving amp.  If you want to look on the Hypex front look at the Nord amps instead of the Acoustic Imagery.
Title: Re: STA-9
Post by: Nidri17 on 10 Jul 2016, 03:57 am
Thank you very much!  I'm new to the hobby and learning everyday.  Until yesterday my short list of amplifiers were Hypex based amplifiers,  the Acoustic Imagery Atsah 500 and the NAD M22.  I have decided to purchase a Parasound P5 preamp,  hopefully it would match nicely with any of these amplifiers.  Now I have to decide on the ST-10 and STA-9(s) as well   :lol:

Agreed with the previous comment. The ST-10 is outstanding.
But perhaps also have a look at the NuPrime Amp Comparison Chart:

http://www.audiocircle.com/index.php?topic=138606.0
Title: Re: STA-9
Post by: rustydoglim on 10 Jul 2016, 04:44 am
Quote
Thank you very much!  I'm new to the hobby and learning everyday.  Until yesterday my short list of amplifiers were Hypex based amplifiers,  the Acoustic Imagery Atsah 500 and the NAD M22.  I have decided to purchase a Parasound P5 preamp,  hopefully it would match nicely with any of these amplifiers.  Now I have to decide on the ST-10 and STA-9(s) as well   :lol:

Thanks. May I know how you get into this hobby? You can PM me if you don't want to elaborate in public. I think we are on the right track to attract new hobbyists into high-end and affordable audio. Some of our products are now approaching DIY pricing (the effort and cost of putting together a Hypex amp is about the same as STA-9).

I will also like to take very opportunity to remind people not to value a product simply based on price alone.
This article explains why we are affordable: http://www.nuprimeaudio.com/index.php/sales-contact/about-us.html#faq_28 (http://www.nuprimeaudio.com/index.php/sales-contact/about-us.html#faq_28)
Title: Re: STA-9
Post by: Eisener Bart on 10 Jul 2016, 09:16 am
Some of our products are now approaching DIY pricing (the effort and cost of putting together a Hypex amp is about the same as STA-9).


Nope.  :D

Hypex NC400 mono kit costs 650 Euro + transportation and it will be without extra cost for assembling if you
may not do it yourself (from my experience - not all music lovers are able to keep soldering iron in hand  :green: ).
Retail price of STA-9 is 650 USD.
Title: Re: STA-9
Post by: maty on 10 Jul 2016, 09:25 am
You are wrong.

You must compare Nuprime ST-10 (stereo) and Nord with Hypex NC500, Sonic Imagery 994Enh-Ticha Dual Discrete Op Amp + Sparkos voltage regulators (stereo). The price is very similar if you live in EU.

With the Hypex standard op amp and regulators the sound is other, the type of class D that many refuse!

The buffer is the key, with Nuprime and Nord.
Title: Re: STA-9
Post by: Eisener Bart on 10 Jul 2016, 05:04 pm
Gentlemen,

I uploaded today my review of STA-9 in my personal blog. Review is on Ukrainian language.
English version is in progress.

For the most impatient guys - you may use special Google tool for translation which I am including to
every my review. Just choose your language. You should understand that translation will be done by robot, so
better to wait English version.

Anyhow - for the moment you may look on photos.

Here you go:
http://eisenerbart.blogspot.com/2016/07/3.html
Title: Re: STA-9
Post by: Eisener Bart on 10 Jul 2016, 05:14 pm
Yeah, and I forgot to say.  :duh:

My compliments to Mr. Jason Lim and the NuPrime Brand! 

You've created a serious product for very-very reasonable money.
I am in Hi-Fi and Hi-End hobby from 2003 and, I beleive, I have enough own experience to compare.

Title: Re: STA-9
Post by: John Casler on 10 Jul 2016, 05:29 pm
Thank you very much!  I'm new to the hobby and learning everyday.  Until yesterday my short list of amplifiers were Hypex based amplifiers,  the Acoustic Imagery Atsah 500 and the NAD M22.  I have decided to purchase a Parasound P5 preamp,  hopefully it would match nicely with any of these amplifiers.  Now I have to decide on the ST-10 and STA-9(s) as well   :lol:

All good gear to consider, and glad you are looking at NuPRIME.

As some have said above, choosing between the STA-9 and the ST-10 will be based on several considerations.

1) Price:  A pair of STA-9 = $1298  An ST-10 = $1595
2) Power Needed/Wanted: The STA-9 bridged is 290wpc  The ST-10 is 150wpc
3) Tone/Sound:  The STA-9 is slightly warmer and sepia toned  The ST-10 is refined, transparent and accurate

The above are only a small list to consider, since in the end the sound you will generate will also depend on Speakers, Room and Associated gear.

Speaking of associated gear, I see you are considering the excellent Parasound P5, but since you have now discovered NuPRIME, you may also want to look at the DAC-9 and the DAC-10.  Often times people see the DAC designation and don't realize that they really are  Preamp/DACs, with really high quality parts (especially the volume controls) and have great sonic synergy to the NuPRIME amps.



Title: Re: STA-9
Post by: Jg107 on 10 Jul 2016, 07:14 pm
Thanks for all the replies,  I really appreciate it!

My current setup-

Marantz UD7007 player
Denon x3200 AVR
Emotiva XDA2 DAC (to be replaced)
Adcom GFA 5800 (to be replaced)
JBL Studio 500 series speakers
Panamax M5500-EX power conditioner

I started in the hobby last Black Friday when I purchased a Denon X3200 AVR,  little did I know I would become addicted to the hunt for better sound.  Since then,  I went through Monitor Audio Silver speakers,  B&W 600 series speakers and now my current JBL Studio 500 series speakers.  The Monitor Audio and B&W speakers were good but a little too bright,  and for some odd reason these JBL sound magical to me  :lol:.  The main reason I have decided to go with a Parasound P5 was for the features of HT bypass,  tone controls,  and the subwoofer crossover.  I am still open to suggestions on the preamp,  it would be nice to have a matching brand system.  Also for the record,  the main speakers are 250 watts max, 92db sensitivity,  and are 6ohm.

Thanks!
Title: Re: STA-9
Post by: Eisener Bart on 10 Jul 2016, 07:33 pm
ince then,  I went through Monitor Audio Silver speakers,  B&W 600 series speakers and now my current JBL Studio 500 series speakers.

Right choice, man! I also prefer JBLs from such list.
Title: Re: STA-9
Post by: RoadTripper on 10 Jul 2016, 09:40 pm
Is there an analogue to Moore's Law such that every X years audio gear bests or matches gear that cost twice as much as the gear that was being sold X years ago? In other words, what can the STA-9 compete with from just a few years ago. Or doesn't it work that way at all.

Title: Re: STA-9
Post by: snoocher on 10 Jul 2016, 10:42 pm
I recently bought an IDA-8 and am astounded by it. It's for my casual listening in the living room with some bookshelf speakers - B&W CM1s. Don't hold that against me.  :icon_lol:

For my serious system, I have a refurbished, rebuilt, and upgraded 30 year old Adcom GFA-555. It's amazing - and pumps out plenty of power into my 805D2s. 325WPC. I'm a B&W guy...sue me.

But here's where I can provide some guidance. NuPrime clearly is high end at an affordable price. Follow John's advice above on the amps. Don't worry about the 'max' on your speakers. That's irrelevant. You want the headroom. They can handle 500 WPC. It's driving speakers too hard with lower powered amps that's the problem. Just be smart.

And I'd seriously look at the DAC-9 or DAC-10. I'm happy with my Wyred4Sound DAC-2, but instead of upgrading it to an SE, I'll probably end up with the upgraded DAC-10.

Parasound makes great gear, but it's kind of 'yesterday'. This NuPrime stuff is the future.


Thanks for all the replies,  I really appreciate it!

My current setup-

Marantz UD7007 player
Denon x3200 AVR
Emotiva XDA2 DAC (to be replaced)
Adcom GFA 5800 (to be replaced)
JBL Studio 500 series speakers
Panamax M5500-EX power conditioner

I started in the hobby last Black Friday when I purchased a Denon X3200 AVR,  little did I know I would become addicted to the hunt for better sound.  Since then,  I went through Monitor Audio Silver speakers,  B&W 600 series speakers and now my current JBL Studio 500 series speakers.  The Monitor Audio and B&W speakers were good but a little too bright,  and for some odd reason these JBL sound magical to me  :lol:.  The main reason I have decided to go with a Parasound P5 was for the features of HT bypass,  tone controls,  and the subwoofer crossover.  I am still open to suggestions on the preamp,  it would be nice to have a matching brand system.  Also for the record,  the main speakers are 250 watts max, 92db sensitivity,  and are 6ohm.

Thanks!
Title: Re: STA-9
Post by: snoocher on 10 Jul 2016, 10:48 pm
It COULD work that way, and I think Jason and NuPrime are in that direction. But normally with the big boys in this game they find a 1% improvement, market it as unbelievable and earth-shattering, get the audio media to write a similar review, and increase the price from a previous model by at least 10-15%.

This industry and hobby is more like wine. Most top end bottles are certainly great, but when you find the one that's just a touch less 'amazing' for a fraction of the price, that's when you really know that you've done your research and can feel great about. And get just as much enjoyment with a lot of money left over...

Is there an analogue to Moore's Law such that every X years audio gear bests or matches gear that cost twice as much as the gear that was being sold X years ago? In other words, what can the STA-9 compete with from just a few years ago. Or doesn't it work that way at all.
Title: Re: STA-9
Post by: John Casler on 11 Jul 2016, 12:21 am
  The main reason I have decided to go with a Parasound P5 was for the features of HT bypass,  tone controls,  and the subwoofer crossover.  I am still open to suggestions on the preamp,  it would be nice to have a matching brand system. 

Thanks!

Yes, I used to be a JBL dealer when those first came out and liked them a lot.

Regarding the elements of consideration for the preamp:

Both the DAC-9 and DAC-10 have "input memory".  That means if you run your HT L&R inputs in through the analog inputs, you simply set the VOLUME to 94-99db and it is the same as HT bypass since the signal flows straight through at the same level whenever you select it.

Neither of them have "tone" controls as that would disrupt the purity of the signal.  Unless your speakers or other system components have irregular Frequency Responses, tone controls are generally not wanted for that reason.

Both DAC-9 and DAC-10 have RCA outputs that many use for adding a sub to the system.  No need for "on board" cross-over adjustment for most modern subs have both "low pass" frequency adjustments, and basic volume settings, which should be all you need.   You just set the subs Low Pass Filter to where you want it to be, to blend with your main speakers.  In fact, most are continuously variable dials and not "fixed" at a small selection of settings like AVR and Preamp bass management.  If however you want the bass management of reducing the bass to your mains, on board can be for you.

Once the Sub volume is blended, the main gain of the DAC-9/10 would control everything for two channel listening.

I mention these things since you did say, you are rather new to the hobby, and sometimes all the options can cause confusion.  And that is not to say, you may not actually need or want those features, but for more serious music listening, some of them can reduce fidelity, or are redundant.



Title: Re: STA-9
Post by: Eric Gustafsson on 11 Jul 2016, 06:21 am
Gentlemen!
Please remember that it is STA-9 we are discussing here.  :eyebrows:
Title: Re: STA-9
Post by: RoadTripper on 12 Jul 2016, 05:12 am
Let me ask my question about the STA-9 another way. Would it have been possible for the STA-9 to have been developed and marketed at its current price, say, 10 years ago? If not, would it be because of technology improvements along the lines of Moore's law or because of design breakthroughs that had not yet occurred?
Title: Re: STA-9
Post by: Eisener Bart on 12 Jul 2016, 08:33 am
Let me ask my question about the STA-9 another way. Would it have been possible for the STA-9 to have been developed and marketed at its current price, say, 10 years ago? If not, would it be because of technology improvements along the lines of Moore's law or because of design breakthroughs that had not yet occurred?

10 years ago Class D was in the cradle. Nothing to compare.  :D
Title: Re: STA-9
Post by: gregfisk on 13 Jul 2016, 03:47 am
All good gear to consider, and glad you are looking at NuPRIME.

As some have said above, choosing between the STA-9 and the ST-10 will be based on several considerations.

1) Price:  A pair of STA-9 = $1298  An ST-10 = $1595
2) Power Needed/Wanted: The STA-9 bridged is 290wpc  The ST-10 is 150wpc
3) Tone/Sound:  The STA-9 is slightly warmer and sepia toned  The ST-10 is refined, transparent and accurate

The above are only a small list to consider, since in the end the sound you will generate will also depend on Speakers, Room and Associated gear.

Speaking of associated gear, I see you are considering the excellent Parasound P5, but since you have now discovered NuPRIME, you may also want to look at the DAC-9 and the DAC-10.  Often times people see the DAC designation and don't realize that they really are  Preamp/DACs, with really high quality parts (especially the volume controls) and have great sonic synergy to the NuPRIME amps.

John,

Can you tell me with these two amps, does the upper midrange and highs soften up a bit (less glare) with the dual STA-9 compared to the ST-10? I'm still trying to decide, and while the guide is useful and I realize the only way to really know is to put them in my system, can you shed any light on this?

Or perhaps I will wait and just buy the K-38 which is what I really want :thumb:
Title: Re: STA-9
Post by: rustydoglim on 13 Jul 2016, 04:18 am
Audio technology takes longer time to advance than PC or mobile phones. But also there are just a handful of companies doing advance high power  class-D research (as far as I know there are only three, Nuprime being one of them). The chip companies (TI, Analog Device, ST, etc) are focusing on DAC and class-D integration.
Here's a prototype of STA-9 junior, it sounded like a lite version of STA-9, mainly for DIY, low cost pro audio, commercial, or beginning audiophiles.

It is about 3" x 2", very small and capable of 70W per channel.  The photo shows two mono amp board powered by a 200W SMPS (at the top cut off from photo). It sounded very good. This is still an R&D project just to show that it takes a long time to come up with new products.  It is just as challenging to come up with a cheaper and yet good sounding amp. Even when it sounded good as a R&D prototype, a lot has to be done to bring it to the market.

(http://www.audiocircle.com/image.php?id=146746)
Title: Re: STA-9
Post by: Eisener Bart on 13 Jul 2016, 08:36 pm
Gentlemen,

as I promised before.  :D

Review on English here.
http://eisenerbart.blogspot.com/2016/07/killers-of-class-ab.html
Title: Re: STA-9
Post by: John Casler on 13 Jul 2016, 09:27 pm
John,

Can you tell me with these two amps, does the upper midrange and highs soften up a bit (less glare) with the dual STA-9 compared to the ST-10? I'm still trying to decide, and while the guide is useful and I realize the only way to really know is to put them in my system, can you shed any light on this?

Or perhaps I will wait and just buy the K-38 which is what I really want :thumb:

Hi Greg,

Well many who follow NuPRIME know that my "personal" favorite (since I can't afford the Ref 20) is the MCH K-38, so no argument on waiting for the ability to get that one.

That said, the STA-9 "certainly" has a more relaxed presentation of the highs and mids, but I would not represent the ST-10 as having "glare".  It is just more forward and evident, without edge, grate or glare (unless the recording has it)

Strangely enough have a bit more time on the STA-9, I found that I notice the vocal a bit more  :scratch:  Not sure why, and I need to A/B with the ST-10 to actually confirm that.

And I am now using the EVOKE EDDIE speakers (like we used at the SHOW) and just tried an experiment adding a "BASS RAMP" :thumb: to the Stand.

And the BASS is crazy good with the STA-9 and the BASS RAMP.  So the take home, is that even though I didn't change the amp, the BASS RAMP displayed the reproductive ability of the STA-9 in the bass, as well as what the speaker can do.

Ohhhhh YEAH :green:

Maybe this weekend I will have the opportunity to do an A/B/C with the ST-10 and the K-38.

I can certainly say that the ST-10 is more forward, and more transparent through the upper mids and highs, without being bright.

The STA-9 is "Sepia Toned" and more relaxed, but certainly not lacking in detail or high end.

So far my K-38 fan status is still intact.   8)
Title: Re: STA-9
Post by: Letitroll98 on 13 Jul 2016, 09:46 pm
Thanks Eisener, good review.  I'm more sold on the STA-9 than ever.  I think I'm going to try one amp and see how it goes.  I have a small room and don't listen at loud levels.

A friend of mine who doesn't like class D and owns an audio equipment company says the self oscillating nature of the amp will transmit an AM signal through the speaker wires causing all kinds of obvious problems.  Has anyone experienced this?  You would need an AM radio to pick up the interference separate from the music signal.  And does NuPrime use any technology to combat this?
Title: Re: STA-9
Post by: Eisener Bart on 13 Jul 2016, 10:20 pm
Thanks Eisener, good review.  I'm more sold on the STA-9 than ever.  I think I'm going to try one amp and see how it goes.  I have a small room and don't listen at loud levels.

A friend of mine who doesn't like class D and owns an audio equipment company says the self oscillating nature of the amp will transmit an AM signal through the speaker wires causing all kinds of obvious problems.  Has anyone experienced this?  You would need an AM radio to pick up the interference separate from the music signal.  And does NuPrime use any technology to combat this?

You are welcome.

I have receiver, I can check it.
Title: Re: STA-9
Post by: Eric Gustafsson on 14 Jul 2016, 12:12 pm
Gentlemen,

as I promised before.  :D

Review on English here.
http://eisenerbart.blogspot.com/2016/07/killers-of-class-ab.html

Great review Sergii.  :thumb:
Title: Re: STA-9
Post by: Eisener Bart on 14 Jul 2016, 12:15 pm
Great review Sergii.  :thumb:

Thank you, Eric. I liked it too.  :green:
Title: Re: STA-9
Post by: gregfisk on 14 Jul 2016, 02:45 pm
Sergii,

Thank you for the review, very well done. I wonder what the recessed sound stage would sound like on my speakers? I don't have anything behind them, it's all open but they are O.B.
Title: Re: STA-9
Post by: Jg107 on 20 Jul 2016, 05:43 am
I would like to thank John Casler for the demo of the STA-9 and ST-10 today.  I was very impressed of how well they sounded in his "man cave".  After about an hour of questions and listening to music,  I left with a pair of STA-9s!  Next up: Dac-9/10,  interconnects, and power cords  (what are some of everyone's favorites?).  Thanks again John!!     
Title: Re: STA-9
Post by: Letitroll98 on 20 Jul 2016, 06:22 am
Why did you pick the STA-9's over the ST-10?
Title: Re: STA-9
Post by: gregfisk on 20 Jul 2016, 07:00 am
Why did you pick the STA-9's over the ST-10?
     

Yes that, also what differences did you hear in the presentation?
Title: Re: STA-9
Post by: Jg107 on 20 Jul 2016, 08:32 am
Why did you pick the STA-9's over the ST-10?

I have very sensitive hearing,  the ST-10 was a touch too edgy for me (I hope that's the correct terminology).  There were 2 notes from one song that made me almost cringe.  I did not experience this with the STA-9s.  For the most part it was close between the two amplifiers.  If John had a DAC-9 to demo along with the DAC-10,  I could of went home with the ST-10. 

     

Yes that, also what differences did you hear in the presentation?

I noticed a higher level of detail with the ST-10.  The STA-9 was warmer and overall more pleasing to my ears.  I believe the comparison chart is spot on when comparing these two models.   

I have been enjoying the STA-9s for over 6 hours straight so far... :lol:


       
 
Title: Re: STA-9
Post by: Letitroll98 on 20 Jul 2016, 11:23 am
Thanks for the reply.  I love detail and a warmish sound at the same time, so I've been going back and forth.  Your answer helps a great deal.  Enjoy.
Title: Re: STA-9
Post by: John Casler on 20 Jul 2016, 04:52 pm


I have been enjoying the STA-9s for over 6 hours straight so far... :lol:


       

And THAT is what we like to hear.  The main goal is long term enjoyment.   :thumb:

Great to see you yesterday Jeff.
Title: Re: STA-9
Post by: gregfisk on 20 Jul 2016, 08:01 pm
Thanks for the reply.  I love detail and a warmish sound at the same time, so I've been going back and forth.  Your answer helps a great deal.  Enjoy.

Letitroll98, I'm in the same exact boat :duh: I want the warmth as I think it will go better with my other components but I love micro detail as well.

Jg107, thank you for your great answer, I think you summed it up well, enjoy the amps. Now, if I could only figure out a way to listen to both in my system before buying :scratch:
Title: Re: STA-9
Post by: jonbee on 20 Jul 2016, 10:53 pm
Thanks for the reply.  I love detail and a warmish sound at the same time, so I've been going back and forth.  Your answer helps a great deal.  Enjoy.
Matchups are everything. In my system, I found the ST-10 to be ultra smooth and neutral, even a little laid back on top compared to my n-cores. I would not want any less detail or more warmth. If the STA-9 is warmer, I wouldn't even consider it for my system.
Also, cabling and power conditioning in particular have big roles here. They can affect tonality in a major way.
So- think abut which direction you want to take your system. If speakers and front end have problems, don't try to fix them by a choice of amps. In general, the more neutral is the better choice long term, imo.
Title: Re: STA-9
Post by: jonbee on 20 Jul 2016, 11:00 pm
Thanks for the reply.  I love detail and a warmish sound at the same time, so I've been going back and forth.  Your answer helps a great deal.  Enjoy.
Just to add- of course the real matchup is with the listener and his tastes. I'm sure the STA-9 is very good, and your own satisfaction is the only touchstone.
Title: Re: STA-9
Post by: John Casler on 20 Jul 2016, 11:05 pm
Matchups are everything. In my system, I found the ST-10 to be ultra smooth and neutral, even a little laid back on top compared to my n-cores. I would not want any less detail or more warmth. If the STA-9 is warmer, I wouldn't even consider it for my system.
Also, cabling and power conditioning in particular have big roles here. They can affect tonality in a major way.
So- think abut which direction you want to take your system. If speakers and front end have problems, don't try to fix them by a choice of amps. In general, the more neutral is the better choice long term, imo.

That is correct.  Synergy is key.

Since I use the EVOKE Eddies (and that is what Jeff was listening through) and they have adjustability of the highs and mids, I have them slightly tilted up (hot) on the tweeter.  This is because I (like many over 60) have a little roll-off in the upper frequencies.

I also like to listen at lower levels and Fletcher-Munson also attenuates the highs at my normal listening levels.  We may have listened slightly above that DB range.

So this can make the ST-10 sound slightly bright.  The ST-10 is an incredible amp and in most speakers it will be a big hit.

You must figure your SYNERGY

Title: Re: STA-9
Post by: Eric Gustafsson on 27 Jul 2016, 05:06 pm
It has crossed my mind to go for a K-38, but still four STA-9 is cheaper then one K-38. At least here in Sweden.

Today I have decided to go for K-38 instead of my two STA-9. I've made a deal with my local dealer and waiting for the delivery date.
Title: Re: STA-9
Post by: drumnman2 on 10 Aug 2016, 01:27 pm
John, any progress on the bridged STA 9 comparisons you were working on ?
Title: Re: STA-9
Post by: John Casler on 11 Aug 2016, 01:40 am
John, any progress on the bridged STA 9 comparisons you were working on ?

Hi Drumnman2,

My problem is keeping them in the system long enough to get a good assessment.

As soon as I get them set up, someone comes in and purchases them.  Good problem to have  :thumb:

But, most of the general perceptions posted by myself and others is pretty accurate.

Of course they have a smoother sound than the ST-10 and K-38, and it is oh so slightly less refined, which you would expect from the price differences.  I did notice they exhibited great VOCALS that were super clear, and not expected.

Obviously the ST-10 will have more "detail" and be a bit more aggressive than the STA-9, but when bridged the STA-9 has an ease of power and grace at the same time.

Much will be speaker, room and system matching when selecting the NuPRIME Amp. 

My additional problem when I was listening and comparing was the every time I switched from the ST-10 to the STA-9 I would get entranced with the sound, enjoying it so much, I didn't want to switch back.

I think you will be fine with whatever amp you select, as the sonic signatures of each is complete and musical.  It is just the abilities and the specific characters that might fit "your" system and preferences that should be considered.
Title: Re: STA-9
Post by: JackD on 11 Aug 2016, 02:25 am
John

You continue to categorize the ST-10 based on listening tests with speakers that you have admitted to tailored to your preference by adjusting them to have more energy in the upper frequency regions.  So yes the two amps that have more in common with the IDA-8 will sound more natural.  Put the speakers back to neutral and test again.  You are the only one I have ever heard call the ST-10 aggressive.  You are doing a great amp a disservice.
Title: Re: STA-9
Post by: John Casler on 11 Aug 2016, 03:07 am
John

You continue to categorize the ST-10 based on listening tests with speakers that you have admitted to tailored to your preference by adjusting them to have more energy in the upper frequency regions.  So yes the two amps that have more in common with the IDA-8 will sound more natural.  Put the speakers back to neutral and test again.  You are the only one I have ever heard call the ST-10 aggressive.  You are doing a great amp a disservice.

Hi Jack,

Thanks for the feedback.

I need to be clear, that to me "more aggressive", or "more laid back" are relative and not negative terms.

When I employ the term aggressive (by comparison) it means more dynamic and with greater contrasts.

I use the same settings on my speakers for all amp or gear comparisons so that will always produce the same relativity.

And to anyone who reads my comments on these amps, I find them to actually be well priced and placed as far as performance and quality of sound.  That is, the STA-9 is not quite at the same level in overall sound qualities as the ST-10, K-38, or Reference 18 and 20.

There seems to be a clear and escalating quality as you go up the line.  In most cases, one would look for "refinements" to the sounds of amps as you move up the line, and that is what occurs with NuPRIME.  (From the IDA-8 to the Reference 20)

So to reiterate, the ST-10 is an "exceptional" amp at any price, and the only amps I like better, are the K-38 and I assume the REF20 (but I haven't had opportunity to spend time with them yet)

So I might hope that would correct any impression that "aggressive" when I use it as a descriptor, is comparing primarily "dynamic abilities". When I hear a more crisp "snap" to a snare, or instant rise of a percussive sound, I describe that as more aggressive dynamics.

And a forward aggressive sound is only considered negative, if it is harsh, or overtly so, to the point it is distracting or not real sounding.

I tend to think that, in general, most amps and speakers are less real sounding because they lack the dynamics heard in real space.

In the future I will likely use "aggressive" and "responsive" to further add to being able to describe those aspects as "positive".

My comparison also means that for those looking for something "laid back", or smoother, they will likely be perfectly happy with the STA-9, which certainly does have its roots in the IDA-8.

I apologize for rambling on, but I wanted to make sure no one felt I was suggesting the ST-10 was less refined in any way.

I am currently using it in my system for a while and love it.
Title: Re: STA-9
Post by: JackD on 11 Aug 2016, 03:45 am
John

I understand that you use the same settings on the Evoke's for every equipment comparison, just as you did with Brian's speakers whose basic DNA they share. My point is that the tweaking of the speaker's balance upward in tonality to compensate for either personal preference or age induced hearing dececiencies changes the perspective on other equipment relative to a "neutral" baseline speaker which I suspect the designer intended.  So it changes the prespective one has on the components relative to each other and until tonight you have never explained "your definition" of the terms yet you have used them for months.  I have used the ST-10 with speakers as varied as the Nola KO, Odyssey Lorelei, Golden Ear Triton 5 and the Spatial M3 Turbo S and aggressive is a term I would have never thought of.  While when I tried the IDA-8 with all of the same speakers the only one that didn't make me think it "subdued" on the top end was the Triton 5 which like the Evoke has a ribbon tweeter.  Like you never heard the REF 20's but I find it hard to think it better.  My opinion of the ST-10 is pretty much in line with Stephen Stone's and it is amongst my first recommendation to people looking for a great amp at a fair price. We may be saying similar things just differently.
Title: Re: STA-9
Post by: Eisener Bart on 11 Aug 2016, 08:42 am
Hi Jack,

Thanks for the feedback.

I need to be clear, that to me "more aggressive", or "more laid back" are relative and not negative terms.

When I employ the term aggressive (by comparison) it means more dynamic and with greater contrasts.

I use the same settings on my speakers for all amp or gear comparisons so that will always produce the same relativity.

And to anyone who reads my comments on these amps, I find them to actually be well priced and placed as far as performance and quality of sound.  That is, the STA-9 is not quite at the same level in overall sound qualities as the ST-10, K-38, or Reference 18 and 20.

There seems to be a clear and escalating quality as you go up the line.  In most cases, one would look for "refinements" to the sounds of amps as you move up the line, and that is what occurs with NuPRIME.  (From the IDA-8 to the Reference 20)

So to reiterate, the ST-10 is an "exceptional" amp at any price, and the only amps I like better, are the K-38 and I assume the REF20 (but I haven't had opportunity to spend time with them yet)

So I might hope that would correct any impression that "aggressive" when I use it as a descriptor, is comparing primarily "dynamic abilities". When I hear a more crisp "snap" to a snare, or instant rise of a percussive sound, I describe that as more aggressive dynamics.

And a forward aggressive sound is only considered negative, if it is harsh, or overtly so, to the point it is distracting or not real sounding.

I tend to think that, in general, most amps and speakers are less real sounding because they lack the dynamics heard in real space.

In the future I will likely use "aggressive" and "responsive" to further add to being able to describe those aspects as "positive".

My comparison also means that for those looking for something "laid back", or smoother, they will likely be perfectly happy with the STA-9, which certainly does have its roots in the IDA-8.

I apologize for rambling on, but I wanted to make sure no one felt I was suggesting the ST-10 was less refined in any way.

I am currently using it in my system for a while and love it.

So instead of term "aggressive" better use "more detailed", neh?  :D
Title: Re: STA-9
Post by: drumnman2 on 11 Aug 2016, 12:34 pm
Thanks John. I have been enjoying an STA 9 for 8 months now and am just considering to get another and bridge or go to the ST 10. I am aware of the basic sound differences between  the two. I remember once you saying that the STA 9's sounded even better in bridged mode and just wondered with more time if you still felt that way. Tons of system variables I know. I'll just go ahead and order another 9 and make up my own mind which is what matters anyhow, thanks.
Title: Re: STA-9
Post by: Eisener Bart on 11 Aug 2016, 12:42 pm
Thanks John. I have been enjoying an STA 9 for 8 months now and am just considering to get another and bridge or go to the ST 10. I am aware of the basic sound differences between  the two. I remember once you saying that the STA 9's sounded even better in bridged mode and just wondered with more time if you still felt that way. Tons of system variables I know. I'll just go ahead and order another 9 and make up my own mind which is what matters anyhow, thanks.

I am wating ST-10 for reviewing.  8)
Title: Re: STA-9
Post by: John Casler on 11 Aug 2016, 05:01 pm
So instead of term "aggressive" better use "more detailed", neh?  :D

Yes, keep in mind this was a relative comparative evaluation.

The ST-10 while it was initially called a "near reference" component, in my mind is certainly "reference class".  This has been demonstrated by the professional reviewers, and the owners who have spent time with it.

It is more aggressive at mining detail, and producing micro and macro dynamics with immediacy, than the amps below it.

This is opposed to "more subdued", or more "laid back", which it is not. (by comparison)

I might add, that I tend to "prefer" more aggressive amps, with those qualities, over the more soft, smooth, warm, soothing, laid back sonics.

Title: Re: STA-9
Post by: John Casler on 11 Aug 2016, 05:08 pm
Thanks John. I have been enjoying an STA 9 for 8 months now and am just considering to get another and bridge or go to the ST 10. I am aware of the basic sound differences between  the two. I remember once you saying that the STA 9's sounded even better in bridged mode and just wondered with more time if you still felt that way. Tons of system variables I know. I'll just go ahead and order another 9 and make up my own mind which is what matters anyhow, thanks.

Yes, as has been stated and posted many times, there seems to be something unique to the STA-9 and the K-38 technology/topology, that "improves" the sound a bit when bridged.

This is in comparison to older amps that when bridged suffer from reduced stability, increased distortions, S/N.

Of course part of this is simply increased headroom from the additional power, but it seems like more than this.  I believe Jason posted the technical reasons a few months ago.
Title: Re: STA-9
Post by: Eisener Bart on 11 Aug 2016, 05:13 pm
Yes, as has been stated and posted many times, there seems to be something unique to the STA-9 and the K-38 technology/topology, that "improves" the sound a bit when bridged.

This is in comparison to older amps that when bridged suffer from reduced stability, increased distortions, S/N.

Of course part of this is simply increased headroom from the additional power, but it seems like more than this.  I believe Jason posted the technical reasons a few months ago.

STA-9 has interesting THD+N:
0.02% (Stereo) / 0.01% (Mono).  8)
Title: Re: STA-9
Post by: Eisener Bart on 11 Aug 2016, 05:13 pm
Yes, keep in mind this was a relative comparative evaluation.

The ST-10 while it was initially called a "near reference" component, in my mind is certainly "reference class".  This has been demonstrated by the professional reviewers, and the owners who have spent time with it.

It is more aggressive at mining detail, and producing micro and macro dynamics with immediacy, than the amps below it.

This is opposed to "more subdued", or more "laid back", which it is not. (by comparison)

I might add, that I tend to "prefer" more aggressive amps, with those qualities, over the more soft, smooth, warm, soothing, laid back sonics.

Thus, Ref-20 will be the aggressivist NuPrime's Power Amp.  :D
Title: Re: STA-9
Post by: John Casler on 11 Aug 2016, 05:17 pm
STA-9 has interesting THD+N:
0.02% (Stereo) / 0.01% (Mono).  8)

That is exactly what I was talking about.

In most amps distortion "doubles" and stability worsens. 

With the STA-9 and K-38, it seems this is not the case.
Title: Re: STA-9
Post by: John Casler on 11 Aug 2016, 05:18 pm
Thus, Ref-20 will be the aggressivist NuPrime's Power Amp.  :D

 :lol:

Title: Re: STA-9
Post by: rustydoglim on 14 Aug 2016, 08:04 pm
Typically bridging is done by using OpAmp to invert one set of signals, which resulted in more distortion.
Our bridging circuit is done by using transistors.  Transistors are the fundamental building blocks of electronics circuit but many engineers don't design circuit with transistors anymore (similarly, who writes in assembly language? Most software engineers write in object oriented language and scripts). Many high level functions are integrated into complex chips as building blocks. There are literally unlimited number of circuits that can ben created out of transistors but it requires more experience and in-depth understanding of various transistors. Fortunately our chief engineer has decades of experience.
Title: Re: STA-9
Post by: Eisener Bart on 14 Aug 2016, 09:36 pm
Typically bridging is done by using OpAmp to invert one set of signals, which resulted in more distortion.
Our bridging circuit is done by using transistors.  Transistors are the fundamental building blocks of electronics circuit but many engineers don't design circuit with transistors anymore (similarly, who writes in assembly language? Most software engineers write in object oriented language and scripts). Many high level functions are integrated into complex chips as building blocks. There are literally unlimited number of circuits that can ben created out of transistors but it requires more experience and in-depth understanding of various transistors. Fortunately our chief engineer has decades of experience.

Thank you, Jason!
Title: Re: STA-9
Post by: Bill_Bill on 28 Aug 2016, 05:38 am
Hi Lim and other members, just wandering can the sta-9 use T3.15A fuse as replacement for the original T3A as the T3.15A has more choice, any negative affect? And can anyone please advise what is the main difference in sound quality compare to stereo mode and in bridge mode (mono block)? Thanks a lot!
Title: Re: STA-9
Post by: John Casler on 30 Aug 2016, 08:13 pm
Hi Lim and other members, just wandering can the sta-9 use T3.15A fuse as replacement for the original T3A as the T3.15A has more choice, any negative affect? And can anyone please advise what is the main difference in sound quality compare to stereo mode and in bridge mode (mono block)? Thanks a lot!

Not sure regarding the fuses, that is a tech support determination.

But, I think most have confirmed that the "bridged" STA-9 has improved sonic properties.

These are generally mentioned as, Better and Deeper Bass, Improved Dynamics, more Relaxed Presentation, Blacker Backgrounds, slightly more Transparency, and Better Imaging and Soundstage.

Much of this is due to two primary factors:

1) Bridging increases Power from 120wpc to 290wpc
2) Bridging actually improves Noise/Distortion Numbers.

Seldom does anyone purchase a single STA-9 anymore, or they grab a second soon after.
Title: Re: STA-9
Post by: Bill_Bill on 31 Aug 2016, 01:05 pm
Thanks John! Now thinking might get another sta-9.
Title: Re: STA-9
Post by: akopperl on 5 Sep 2016, 12:43 am
Deleted
Title: Re: STA-9
Post by: srb on 5 Sep 2016, 12:55 am
If you connect the amp in mono mode, the manual states to use the top speaker outputs (both posts red).  In this scenario, which post is the + terminal and which is the - terminal?

They're marked + / - separately for BTL mode.

 (http://www.audiocircle.com/image.php?id=149782)

Steve
Title: Re: STA-9
Post by: Rx8man on 23 Sep 2016, 04:12 pm
Does the STA-9 go into 2ohms like my Ref9 V2SE's?

I'm thinking of auditioning two STA-9's to compare.

If they retain the liquid sound I'm getting, with the additional power and "modern" technology, that'd be nice.
Title: Re: STA-9
Post by: rustydoglim on 27 Sep 2016, 05:18 pm
No problem with 2 ohm.
Title: Re: STA-9
Post by: zwizardofoz on 5 Oct 2016, 09:53 am
Is the gain the same over both RCA and XLR @ 22dB ???

I think 22 is quite low as most amps I see are are in the 28-29 range. Similarly is the same over when in bridged mode?

It would be really nice to see data posted like Emotiva does of the Precision Audio measurements data on many of its amps http://emotiva.com/resources/media/xpa1/XPA-1gen2_8Ohms_2013-08-09.pdf



Title: Re: STA-9
Post by: Eric Gustafsson on 5 Oct 2016, 05:15 pm
Use, and trust, your ears instead of comparing a lot of technical data.
Title: Re: STA-9
Post by: zwizardofoz on 6 Oct 2016, 11:38 am
I do but the engineer in me wants to know more details so when I do the selling its backed up with the numbers  :thumb:
Title: Re: STA-9
Post by: mrthib on 6 Oct 2016, 05:48 pm
I am looking for nuprime amp to feed my Regas speakers.
Could you tell me how the sta 9 sound compared to the nuforce sta-100 and sta-120 ?
Title: Re: STA-9
Post by: John Casler on 8 Oct 2016, 04:06 pm
I am looking for nuprime amp to feed my Regas speakers.
Could you tell me how the sta 9 sound compared to the nuforce sta-100 and sta-120 ?

In a general sense, the NuFORCE will tend to sound slightly more "clinical" and less "warm".

The term dryer, compared to more liquid might also come to mind.

All three are great amps if matched to complimentary systems.
Title: Re: STA-9
Post by: mrthib on 10 Oct 2016, 08:44 am
okay, the sta 9 is not far better than the sta 100, it is just "different" ?
It also depend a lot of wich pré amp is working with the amp !
Title: Re: STA-9
Post by: SFDude on 10 Oct 2016, 03:46 pm
Waiting for my pair of STA-9s from John. Hope to have impressions up after listening to them for a little on both digital and analog sources.

Funny enough, will have a pair of tube amps to compare them to as well so I'll see how "warm" the STA-9s sound in comparison to actual tubes.

-dave
Title: Re: STA-9
Post by: Eisener Bart on 10 Oct 2016, 04:02 pm
Waiting for my pair of STA-9s from John. Hope to have impressions up after listening to them for a little on both digital and analog sources.

Funny enough, will have a pair of tube amps to compare them to as well so I'll see how "warm" the STA-9s sound in comparison to actual tubes.

-dave

Very interesting to get info regarding such comparison, Dave.
Title: Re: STA-9
Post by: slefley on 10 Oct 2016, 04:17 pm
I am also using a tube amp and like how it sounds with my system but was intrigued by the STA-9 so tried one.  It does many things very well but is noticeably less transparent than the tube amp.  Can someone with experience with a mono pair let me know if they are significantly more transparent than the stereo version?   Or maybe the TDSS modification?
Title: Re: STA-9
Post by: seikosha on 10 Oct 2016, 04:22 pm
I've got an STA-9 and a few tube amps to compare it to.  Tonally the STA-9 does sound a bit tube-like in that it's a little softer sounding.  However, there's more to sounding like a tube amp than getting the tonality right.  For me, the magic in tubes is in the dimensionality of the presentation.  With a good tube amp, the imaging really pops.  Sometimes it's even startling and within each image in a soundstage, tubes can really make the images sounding like they are radiating sound in all dimensions.

Good solid state amps can do imaging really well and present images in a soundstage just as good as tubes, but when you compare them to a good tube amp, there's that special aspect of dimensionality that's missing.  Once you hear it, you'll know it.

Title: Re: STA-9
Post by: rustydoglim on 10 Oct 2016, 07:55 pm
Did you try STA-9 mono or stereo? I agree that if the goal is to 100% mimic tube amp, just using transistors in the design is not enough.
So this is an area of research we are working on.
Title: Re: STA-9
Post by: SFDude on 10 Oct 2016, 10:53 pm
Good solid state amps can do imaging really well and present images in a soundstage just as good as tubes, but when you compare them to a good tube amp, there's that special aspect of dimensionality that's missing.  Once you hear it, you'll know it.

This is a broad statement that's been mentioned often over the many years of tubes vs SS. I hope this isn't a discussion or comparison about that in particular. I enjoy aspects of both technologies in amplification. There's nothing like a good SS amp to grab your speakers by the balls (sorry for any offense on this statement in light of the recent Election news  :oops: :icon_twisted:) and a very well done tube amp topology can also do it with certain tube types as well.

The question is, seikosha, what do you prefer and in which situations? Imaging and spatiality are probably not what I'm going for while playing electronica (or electronic-based generated music like techno/trance/dubstep) but they are important when playing intimate jazz ensemble music.
Title: Re: STA-9
Post by: seikosha on 11 Oct 2016, 02:01 am
Overall, I prefer tubes, but I do appreciate what good SS can do.  I've got two systems (1 tube and 1 SS) set up and enjoy going back and forth depending on the mood.
Title: Re: STA-9
Post by: SFDude on 22 Oct 2016, 09:24 am
Pair of STA-9s delivered!  :D

(http://www.audiocircle.com/image.php?id=152399)

Stuck overseas in Ireland on a work trip.   :(

Will have to wait until later next week to listen to these and get some impressions up. Thanks John for the delivery and great price on these.  :thumb:
Title: Re: STA-9
Post by: Eisener Bart on 22 Oct 2016, 02:16 pm

Will have to wait until later next week to listen to these and get some impressions up. Thanks John for the delivery and great price on these.  :thumb:

Cultural shock is granted.  :D
Title: Re: STA-9
Post by: John Casler on 22 Oct 2016, 04:39 pm
Pair of STA-9s delivered!  :D

(http://www.audiocircle.com/image.php?id=152399)

Stuck overseas in Ireland on a work trip.   :(

Will have to wait until later next week to listen to these and get some impressions up. Thanks John for the delivery and great price on these.  :thumb:

Hi David,

Glad to assist.  Timing is everything.  These should light up your system nicely.

Title: Re: STA-9
Post by: SFDude on 29 Oct 2016, 06:48 pm
So these are my initial impressions after about 2 hours of firing them up and listening to them, cold out of the box (these were demos from John Casler).

I have the following system:
* PS Audio PerfectWave DAC Mk II w/Bridge (have owned this for about 4 yrs now)
* Pair of STA-9 monoblocks
* Spatial M3 Turbo S open baffle speakers
* cords/cables not worth mentioning but a little better than stock and not quite Kimber Monocle XL type ones  :P

My current set up is temporary and I'm only able to connect a MacBook Pro directly via USB to the PWD MkII DAC. I'm using Tidal to stream music initially. (I'm too exhausted after work to setup the more serious config currently which consists of my NAS filled with FLAC files converted from my CD collection.)

This is as much a review of the speakers as they are for the STA-9s, the combination of it. The DAC I'm well aware of its nuances, idiosyncracies and limitations of it, although it is extremely good value for the money if you buy it used today!

I use orchestral soundtrack music (a la Hans Zimmer or 2 Steps From Hell style, grand sweeping dramatic orchestral stuff) to usually break in anything. There are enough swings across the frequency spectrum on any of the dramatic ones to test any system.

First word that comes to mind: dynamic. Wow. This combination is NOT slow. It's quick, immediate and full. Highs are crisp and lows are impactful. Mids are slightly recessed initially (I'm a tube guy traditionally) but I suspect (without measuring anything) that I'm listening to frequency response range that is more flatter than what I am used to.

Second word that comes to mind: impactful. The lower registers from the amp driving the speakers, this combination of it, is noticeable. It is not shy. You can feel it when it hits. I never had this with a pair of Martin Logan Aeons I used to have in the past. My current room setup is similar to what I've had in the past as well. But everything on the bass notes went deep and was impactful thus far.

Again, these are initial listening impressions so take these with a grain of salt. I'll know more as I put some mileage on everything and get everything dialed in a little more. Out of the box, with nary anything done in terms of fine tuning, this is going to be a long-term relationship. For better or worse, but, like any marriage, seems worth exploring in the long run. I suspect happier times ahead more than the frustration.  :green:
Title: Re: STA-9
Post by: rustydoglim on 29 Oct 2016, 07:18 pm
Did anyone (or heard from anyone) ever find that STA-9 bright? I have never heard a single feedback about STA-9 being bright before but got this feedback for the first time. Very puzzling.
Title: Re: STA-9
Post by: seikosha on 29 Oct 2016, 09:09 pm
Did anyone (or heard from anyone) ever find that STA-9 bright? I have never heard a single feedback about STA-9 being bright before but got this feedback for the first time. Very puzzling.

Bright can be a relative term.  I've got one tube amp that can be pretty dark sounding with some speakers.  If that was the only amp I had and had become accustomed to that sound and it was paired with bright speakers, if I switched in a STA 9, I could see myself saying it was bright.  But then again, most amps would sound bright if introduced in that type of system.
Title: Re: STA-9
Post by: SFDude on 30 Oct 2016, 05:06 pm
Did anyone (or heard from anyone) ever find that STA-9 bright? I have never heard a single feedback about STA-9 being bright before but got this feedback for the first time. Very puzzling.

Hope this isn't in reference to my description about the amps' highs as being "crisp". I don't think I meant that to be bright at all.

And no, these aren't bright amps at all. I had a Rotel amp a long long time ago which would take the paint off a car.  :lol:
Title: Re: STA-9
Post by: rustydoglim on 30 Oct 2016, 10:47 pm
The comment came from a reviewer who likes the IDA-16 but find STA-9 bright, and that's make it so puzzling to me.
Title: Re: STA-9
Post by: Bill_Bill on 16 Jan 2017, 02:28 am
Had bought 2 x STA 9 at the weekend and connected both in the bridged mode, one side is louder than the other, trying to change over and reconnect all the cables and also check all the switch again and again but still the same that really makes me crazy :( as I call up the dealer and I need to take public transport to bring both amp all the way to the shop for them to check (far away from where I live). Just wandering does anyone has experience with the same problem? and How come this will happen, because of the QC? Thanks!
Title: Re: STA-9
Post by: John Casler on 16 Jan 2017, 02:51 am
Had bought 2 x STA 9 at the weekend and connected both in the bridged mode, one side is louder than the other, trying to change over and reconnect all the cables and also check all the switch again and again but still the same that really makes me crazy :( as I call up the dealer and I need to take public transport to bring both amp all the way to the shop for them to check (far away from where I live). Just wandering does anyone has experience with the same problem? and How come this will happen, because of the QC? Thanks!

Hi Bill,

Sorry to hear of your issue.  As a dealer, I did have one customer report exactly the same issue.   :scratch:

I had him "check" all his connections and switch settings and the "issue" went away.

I had him CAREFULLY check the following:

1) That the VOLTAGE switch was set properly for the voltage in his area.  In the USA that it 115v.
2) That ALL RCA to XLR switches on the channels were set to the CORRECT input setting
3) That ALL Stereo/Bridged Settings were set to BRIDGED

4) And most importantly that he had read the manual, and looked at the section on how to connect the SPEAKER WIRES when using the bridged mode.

When he performed those tasks again, his issue was solved.  I only hope if you follow those steps that you find that a switch, or wire was in the wrong spot, and you are able to enjoy your STA-9s.

CHECK AND RECHECK. 

Good Luck
Title: Re: STA-9
Post by: Bill_Bill on 16 Jan 2017, 03:13 am
Thanks for your reply! Actually I have checked all the things you mention but still no goal. As I did follow this forum for awhile and in my case one of the amp is much much louder than the other as the vocal image you can hear is go to the one side and the other side does make sound but much softer, and the amp with soft sound is hot in temp. and the louder amp. is just warm in temp. Any idea? Thanks!
Title: Re: STA-9
Post by: RafaPolit on 16 Jan 2017, 05:40 am
If you switch the right amp to be the left and the left to be the right, is the problem 'reversed'?

Is now the other speaker softer than the other? If no, perhaps the problem is in the speakers or in the PRE section. Or perhaps in the cables? If you switch cables, is the problem reversed or does it keep the same 'soft' speaker?

This is the things I would try to determine if the issue is with the Amps or with any other part of the system.

Best of lucks,
Rafa.
Title: Re: STA-9
Post by: Bill_Bill on 16 Jan 2017, 08:37 am
Hi Rafa,

Yes after switch the speaker cables and the vocal shifted from right to left so I am very sure is the power amp itself. Thanks anyway  :)!
Title: Re: STA-9
Post by: rustydoglim on 17 Jan 2017, 05:34 pm
When you report the problem to support or Help Desk, please mention the test that you have done to confirm the problem. And I am sure we or your distributor will fix it.
Title: Re: STA-9
Post by: rustydoglim on 17 Jan 2017, 05:39 pm
Oh, please provide the serial number of both STA-9 to support.  I don't follow such details, may be the gain was changed ?
Because hardware problem doesn't behave like this. Either it has horrible noise (component failure) or no sound at all.
Title: Re: STA-9
Post by: Bill_Bill on 20 Jan 2017, 11:31 pm
Thanks for the reply have arranged to bring those machine and check with the dealer at next week. One thing i forgot to mention is that one come with an UK type power cable and the other is the US type power cable (but i use my own power cable UK type for both machine), anyway i dont think this will make the difference due to export to different country.
Title: Re: STA-9
Post by: MASH on 29 Jan 2017, 08:49 am
Hi,
I'm new in this forum. Have a question. I like to buy STA-9 + DAC-9 with B&W CM9. Wondering if this will work or any comments I will be tankful.
Thank you !
Kind Regards
Title: Re: STA-9
Post by: damguz on 1 Feb 2017, 02:05 pm
Hi,
I'm new in this forum. Have a question. I like to buy STA-9 + DAC-9 with B&W CM9. Wondering if this will work or any comments I will be tankful.
Thank you !
Kind Regards

First of all, Welcome to the site and to Nuprime´s Circle.
CM9´s sound can be a little bit to oriented towards the low frequencies and require a good amp able to control them in that region, so the STA-9 could be an interesting pairing if you like a warm sounding set-up.  Be aware that it could be too much, and you would need to start pluggin ports, playing with speaker positioning, etc.

Personally, I would try the DAC-9 ST-10 combo.  In my mind they sound like a better pairing to your CM9s.  Greater lf control with a neutral amp, feed by a more liquid soundig DAC.
Title: Re: STA-9
Post by: i06marjo on 1 Feb 2017, 10:19 pm
Hi!

I am currently owner of the old Nuforce IA7 v2 and I am looking into buy the DAC9/STA9 combo.

On the STA-9 Product description page it says the following:
"The bandwidth of the front-end circuits of the STA-9 and HPA-9 are up to 300KHZ, which produce a more natural sound. With very low negative feedback, the sound is smooth and relaxed rather than harsh."

Does the ”low negative feedback” mean that damping factor is lower compared to the old Nuforce amps?
I also read in the STA9 manual on Nuprimes homepage that Nuprime ”has extermely high damping factor”.

What is the case regarding low negative feedback and damping factor for the Nuprime STA9?

Also, is the DAC9/STA9 a significant improvement compared to the IA7?

Best Regards
Title: Re: STA-9
Post by: Bill_Bill on 8 Feb 2017, 03:39 am
Just notice that the Nuprime Sta-9 has grand a Qobuzissime award from Europe! :thumb:
Title: Re: STA-9
Post by: John Casler on 8 Feb 2017, 03:49 am

Also, is the DAC9/STA9 a significant improvement compared to the IA7?

Best Regards

I think you will find the STA-9 and DAC-9 a few levels above the IA7 (which actually was actually quite good for that period)

But to answer your question, YES the combo would certainly be a significant improvement.

I just installed an "open box" pair of the STA-9 into my DEMO System earlier to day and straight out of the gate, still cold, they were "just WOW!" with all the REF CUTS I had time to play.   :thumb:

Title: Re: STA-9
Post by: rustydoglim on 9 Mar 2017, 08:53 am
Here's a quote from Jim Merod (recording engineer, audiophile reviewer, professor, and Jazz music album producer) for STA-9 and DAC-9 under review.
http://www.blueportjazz.net (http://www.blueportjazz.net)

THESE  TWO UNITS ARE FANTASTIC BARGAINS . . .

     sonic over-achievers, the precise sort of audio music enhancements

       that the so called "high-end" once promised, seldom delivered, but here

     with your committed honesty and technical brilliance allow any audiophile

      and/or music lover to own for enduring listening benefit.  They are under-priced

       in the current price-bloated marketplace that shames 90% of existing audio

     companies with NuPrime's commitment to musical glory and financial value.

      Few products of any kind in the existing world of audio blather and hoopla

        produce such an astonishing price - value ratio !  I recommend any listener,

     regardless of ability to spend (squandering money on fancy chassis glitter

       of published hype), to consider each of these products not merely as great values

     -- the proverbial "bargain" most people hope for and rarely find -- but great delivery

          systems for any superior audio system -- JIM MEROD
Title: Re: STA-9
Post by: Eisener Bart on 19 Mar 2017, 05:54 am
I finally bought a pair of STA-9.

(http://f21.ifotki.info/org/bc6aed7b854ba2a48534e8956eaaaa595d4ff6272562918.jpg) (http://i-fotki.info/)
Title: Re: STA-9
Post by: gnostalgick on 20 Apr 2017, 12:51 pm
Any opinions on how long they take to break in?  What areas--if any--notably changed with time?
Title: Re: STA-9
Post by: Eisener Bart on 20 Apr 2017, 01:07 pm
Any opinions on how long they take to break in?  What areas--if any--notably changed with time?

Standard time (130-150 hours) will be enough.
Sound will "jump out", I don't remember significant floating during breaking-in process.

Power will be enough to control 95% of speakers on the market, so you may leave breaking-in process for 24 hour.
I left for all night decreasing level on minimum, so you will spend around 1 week for 1st stage of breaking-in.
Title: Re: STA-9
Post by: Eisener Bart on 14 May 2017, 03:43 pm
I received from capitol this Pre Amp 2 days ago for test and probably - for purchase.

It's PS Audio PCA-2 with Analog HCPS (external PSU). This Pre Amp can control 4 channels simultaneously, so I could arrange vertical bi-amping. That's I have another System now.
Title: Re: STA-9
Post by: Samac on 14 May 2017, 09:41 pm
Cool, Sergio. The PCA-2 looks like a great pre. So, are you bi-amping with the T+A and the NuPrime STA-9s?

Cheers,

Scott
Title: Re: STA-9
Post by: Eisener Bart on 15 May 2017, 11:16 am
So, are you bi-amping with the T+A and the NuPrime STA-9s?

No.

Vertical bi-amping
using 2 pcs of STA-9 as stereo amps.
1 channel from every STA-9 cuts to the upper pair of contacts on speakers, 1 channel - to the lower pair.
Title: Re: STA-9
Post by: Samac on 15 May 2017, 03:25 pm
No.

Vertical bi-amping
using 2 pcs of STA-9 as stereo amps.
1 channel from every STA-9 cuts to the upper pair of contacts on speakers, 1 channel - to the lower pair.

Excellent, I bet that sounds great. :thumb: The NuPrime gear is fantastic. My IDA-16 is one of the best amps I've heard. Do you think you'll get a chance to try the NuPrime Ref 20? I hope one day to get to listen to those.

Cheers,

Scott
Title: Re: STA-9
Post by: Eisener Bart on 15 May 2017, 08:00 pm
Excellent, I bet that sounds great. :thumb: The NuPrime gear is fantastic. My IDA-16 is one of the best amps I've heard. Do you think you'll get a chance to try the NuPrime Ref 20? I hope one day to get to listen to those.

Cheers,

Scott

I planned to buy Ref 20, but some circumstances were against me this year.

For the moment I have great space for manoeuvring:
1) I may add 2 pcs of STA-9;
2) I may start to jump to Ref 20 (2 or even 4 pcs).

But for the moment I gonna wait.
Title: Re: STA-9
Post by: Eisener Bart on 15 May 2017, 08:01 pm
I planned to buy Ref 20, but some circumstances were against me this year.

Now I have options:

1) I may add 2 pcs of STA-9;
2) I may start to jump for Ref 20 (2 or even 4 pcs).

But for the moment I gonna wait.
Title: Re: STA-9
Post by: Samac on 15 May 2017, 08:57 pm
I planned to buy Ref 20, but some circumstances were against me this year.

For the moment I have great space for manoeuvring:
1) I may add 2 pcs of STA-9;
2) I may start to jump to Ref 20 (2 or even 4 pcs).

But for the moment I gonna wait.

Either set-up would be excellent, I'm sure. Look forward to seeing how you go.

Cheers,

Scott
Title: Re: STA-9
Post by: John Casler on 15 May 2017, 09:47 pm
I might jump in here and mention, that I am currently using a Pair of STA-9 bridged to Mono, in evaluating the new EVOKE Ruby (http://evokespeakers.com/ruby/) speakers and the combination is WOW!  :o :o

I might add that my "favorite" NuPRIME amp that I have had in my system is the "bridged" K-38, but if it sounds better in this current set up, I will be thrilled.

I also have to try the ST-10, and I have a pair of "still in the box" STA-6, which I plan to also review bridged to 190wpc.

But, my point in commenting, is the absolute incredible SONICS coming from these STA-9 pair with this particular speaker.

In the pecking order of NuPRIME amps, they "should" in most systems be above the STA-6, but slightly below the ST-10, and K-38.

Now this "pecking order" is based basically on price, because as most know, these amps all have slightly different components and stages that offer some sonic qualities that might be preferred.

It is hard to believe the quality of sound now available for these pricing levels.
Title: Re: STA-9
Post by: Eisener Bart on 16 May 2017, 09:28 am

I also have to try the ST-10, and I have a pair of "still in the box" STA-6, which I plan to also review bridged to 190wpc.

I thought about STA-6, but there is no XLR inputs.
Title: Re: STA-9
Post by: jmiguelbarone on 17 Jun 2017, 09:06 am
I read all the topic but the experiences goes from one stereo sta-9 to monoblock mode with 2 sta-9 ... but biamping configuration with 2 stereo sta-9 offers another option.

Yes, you need speakers with 2 pairs of terminals and a preamp with a+b outputs, but in modern times this usually happens.
Somebody test the difference between biamping and monoblock mode with 2 sta-9?
Title: Re: STA-9
Post by: in1unison on 17 Jun 2017, 04:07 pm
@jmiguel

http://totallywired.co.nz/nuprime_sta_9.html

http://www.fairaudio.de/dwt/test/endstufe/2016/nu-prime-sta-9-test-endstufe-verstaerker-class-d-1.html
Title: Re: STA-9
Post by: srb on 17 Jun 2017, 04:16 pm
Somebody test the difference between biamping and monoblock mode with 2 sta-9?

I haven't tested it with the STA-9, but with most 2-way speakers having such a small relative percentage of total power used by the tweeter, testing passive bi-amping with several other amplifiers has always fallen short of the performance gained by having a single more powerful amplifier channel driving both speaker drivers.

Steve
Title: Re: STA-9
Post by: John Casler on 17 Jun 2017, 06:13 pm

Somebody test the difference between biamping and monoblock mode with 2 sta-9?

Although each system and set up is different, IN GENERAL, the "bridged" STA-9 should sound better than the "stereo" configuration.

This is not just because of power distribution, but because "bridging" the amp actually IMPROVES some of the performance qualities.

For example THD improves - (from 0.02% (Stereo) / 0.01% (Mono) - when bridged as do some of the other specs.

As well power output, (thus headroom) more than doubles from 120wpc to 290wpc.

So it is likely that your use would benefit from the bridged performance.
Title: Re: STA-9
Post by: in1unison on 17 Jun 2017, 07:27 pm
Dealer from NZ has different take on STA-9 bridged vs. bi-amped although he does not specify if test was done on 2 or 3-way speakers. Neither is he clear if bi-amping is horizontal or vertical.

http://totallywired.co.nz/nuprime_sta_9.html
Title: Re: STA-9
Post by: Eisener Bart on 18 Jun 2017, 01:40 am
I may say much more about STA-9 now (bi-amping and bridged modes).

Unfortunately I am already 2 weeks at sea with shity Internet. I will prepare post, even with photos, and upload later.
Title: Re: STA-9
Post by: jmiguelbarone on 18 Jun 2017, 01:55 am
Thanks for the answers ... it seems that monoblock configuration wins on preferences :-)
Title: Re: STA-9
Post by: Eisener Bart on 18 Jun 2017, 01:59 am
Thanks for the answers ... it seems that monoblock configuration wins on preferences :-)

not in all respects.
Title: Re: STA-9
Post by: in1unison on 18 Jun 2017, 07:38 am
@Sergii

Thanks, looking forward to your test report.
Title: Re: STA-9
Post by: jmiguelbarone on 18 Jun 2017, 11:43 am
not in all respects.

Yes, we wait your opinions in your test (hungrily  :lol:)
Title: Re: STA-9
Post by: Tan Raymond on 9 Jul 2017, 03:44 am
My first post. Have been using the Marantz PM Pearl Lite (PL)/ SA8005 combi for some years, and just added the Nuprime Dac10. Using it as DAC into the amp. Found it too cold albeit with more detail compared to using the SA8005 dac. Was thinking of adding the ST-10, but worries it will be even "colder" if the PL is removed from the equation. Would 2x sta9 bring back some warmth but retain the details?? My speakers are Harbeth SHL5plus.
Title: Re: STA-9
Post by: JackD on 9 Jul 2017, 03:58 am
Tan

I've owned the 10 combo for well over a year and cold is not at all how I would describe them.  They are neutral which is a good thing to me.  The Harbeth's should be "warm" enough on their own unless you want to go way in that direction.  I would order the ST-10 from somewhere that has a 30 day return policy and try it instead of the STA-9.  You need to leave it powered on though to get the best sound and the same is true of the DAC-10.
Title: Re: STA-9
Post by: dspringham on 9 Jul 2017, 05:02 am
JackD is exactly right. I have the Nuprime 10 combo as well and it is not "cool' to my ears in any way. As far as Harbeth goes? - a fine match with my 40.1's which have a nice natural warmth on their own. The Nuprime 10 pair certainly doesn't tilt the balance any further in that direction. Just right I would say.

Dave
Title: Re: STA-9
Post by: JackD on 9 Jul 2017, 05:25 am
Tan

I own the Marantz HD-CD1 which has the exact same DAC section as the 8005 so I am familiar.  I wouldn't think either one to have a DAC section anywhere near that in the DAC-10.  I only listened to the internal DAC for a couple of discs and then moved on. Don't get drawn into the added power of the 9 mono's as you don't need it and quantity over quality in this case may not be a good thing.
Title: Re: STA-9
Post by: mresseguie on 9 Jul 2017, 06:08 am
Hi, Raymond.

How long have you had the DAC-10?

I ask because it's been my experience that DACs tend to need at least 100 hours to burn in, and as many as 250+ hours to fully burn in. Prior o full burn in, a whole range of unpleasant sounds may be heard. These include tinniness, brightness, dull midrange, goofy bass (yes, goofy is an audiophile word), strident highs, toilet bowl echoes, flat uninteresting music, and who knows what else?

If you haven't run it 200 hours already, keep using it, and keep it turned on all the time. Turning it off overnight results in 'off' music until everything warms up inside.

Best of luck!

Michael
Title: Re: STA-9
Post by: RafaPolit on 9 Jul 2017, 04:41 pm
Raymond, I was myself reluctant to acknowledge what Michael is saying, but I found it to be true nonetheless.

But to answer to your original question, yes! A pair of STA-9s would be warmer than a single ST-10, as per NuPrime's own chart.  It would retain most of the characteristics but with slightly reduced stage, bass extension... you can check the trade offs in the comparison chart.

But if warm is what you are after, there are a lot of people very happy with a pair of STA-9s, so I'm assuming you can't go wrong that way.

I do find the 10s to be neutral rather than cold, but if you think the DAC-10 cold (which I agree is a personal taste!), then by all means the STA-9s will help in that sense!

Best regards,
Rafa.
Title: Re: STA-9
Post by: Tan Raymond on 10 Jul 2017, 03:35 am
Thanks, Jack, Dave, Michael and Rafa for taking the time to read and post your thoughts. I bought the dac10 from Singapore and has less then 100 hours on it yet. Tried it as a pre with my A30 and PL as power amp and as a dac into the PL, both had given me more details, without doubt, but either it's not fully broken in yet, or, I'm having a new auditory experience, is a big question. I am listening to Allan Taylor now as I'm writing this reply, and as mentioned getting amazing details. There is no chance for any "trials/return" as I return to Singapore only twice a year. Guess I'll let it burn in more and hopefully get used to the more neutral sound, then decide on which to add. Thanks again and sorry for a long read.
Title: Re: STA-9
Post by: SFDude on 10 Jul 2017, 06:55 am
Thanks, Jack, Dave, Michael and Rafa for taking the time to read and post your thoughts. I bought the dac10 from Singapore and has less then 100 hours on it yet. Tried it as a pre with my A30 and PL as power amp and as a dac into the PL, both had given me more details, without doubt, but either it's not fully broken in yet, or, I'm having a new auditory experience, is a big question. I am listening to Allan Taylor now as I'm writing this reply, and as mentioned getting amazing details. There is no chance for any "trials/return" as I return to Singapore only twice a year. Guess I'll let it burn in more and hopefully get used to the more neutral sound, then decide on which to add. Thanks again and sorry for a long read.

Raymond,

I think you should probably start a new thread about the DAC-10. It might be worth to provide further observations there. Having said that, I also have a DAC-10 that I use in DAC-only mode now. I can provide more details and also some comparisons with another DAC I have (PS Audio PerfectWave DAC II).

-dave
Title: Re: STA-9
Post by: Tan Raymond on 11 Jul 2017, 02:29 am
Thanks Dave, I came into this thread as I'm considering the sta 9, but looks like many here are favouring the st10, due to it's overall better detail and presentation. I will end here then. Thanks to all.
Title: Re: STA-9
Post by: 1st1015 on 11 Jul 2017, 09:53 pm
I have a sta-9 with Dynaudio Emit M10 bookshelf speakers (6 ohm). Does anyone know if adding a 2nd sta-9 could make any improvement? I mostly play music at low to moderate volume.

I've read that 2 sta-9 in mono is great but does it matter at lower volumes? Or is it more about control at high volume?
Title: Re: STA-9
Post by: rustydoglim on 12 Jul 2017, 04:41 pm
STA-9 in mono mode feels more "punchy" (this is not simply due to extra power, but the custom opamp circuit in mono mode).
But since you play at low volume and probably jazz, classical music, so the improvement won't be dramatic.
Actually you can get just test it with one channel by turning your stereo STA-9 into mono.
Play STA-9 in stereo mode but only either left or right channel. Then mono to the same channel for comparison.
Title: Re: STA-9
Post by: MFM72 on 21 Jul 2017, 06:23 pm
Hi guys,

New to the Circle, would like to get some inputs in regards to prior purchasing a pair of STA-9s.

Currently running a Marantz CD/PM6006 thru KEF LS50 / ATC SCM 11 and I need the extra grunt to get the most out of these speakers hence the pair of STA-9s, apart from the obvious pairing of the DAC-9, is there any other recommendations/ experience that you might have in regards to other brand of pre-amps? Is there anything specific that I should be looking for/at for when looking at other alternative brands of pre-amps WITHOUT losing the 'warmth' expected out of the STA-9s?

FYI my music ranges from mostly female vocals, 4/5 jazz ensembles, progressive house & the occasional classicals ( Vivaldi-esques )..
Title: Re: STA-9
Post by: drumnman2 on 21 Jul 2017, 07:57 pm
The Absolute Sound and also Nuprime, in a follow up, found the STA 9's not a good match for LS50 due to brightness. I am using STA 9 with Sonus Faber and hear no such brightness whatsoever.
Title: Re: STA-9
Post by: jmiguelbarone on 21 Jul 2017, 10:50 pm
Brightness or any other aspect of sound it is the result of all the audio chain, not one particular component. Sometimes something as a power cable or toe in on speakers can do significant changes in the sound.

The brave reviews on the major press with the LS50 doesn't say that this speaker is "bright".

What do you like more? the LS50 or the ATC scm11 ... both are great speakers, really.
Title: Re: STA-9
Post by: MFM72 on 22 Jul 2017, 12:48 am
The Absolute Sound and also Nuprime, in a follow up, found the STA 9's not a good match for LS50 due to brightness. I am using STA 9 with Sonus Faber and hear no such brightness whatsoever.

Have done a bit research on the LS50s so-called 'brightness' and users have found using tube amps resolving the 'problem' hence the decision to use the STA-9s for their 'tube-like'/warm sound. I notice that the LS50s are very sensitive to cable selections, most noticeably from my recent switch from Audioquest FLX/SLip4 to Telerium Q Blue, where the mentioned 'brightness' was most noticeable ( too much tech i guess in the combo :) )

Was considering tube-amps i.e. Primalunas, Unison Research, Bob Carver Black Magic, etc ( surprisingly it 'gels' with these so-called 'low-wattage' amps) but personally don't like the hassle that comes with it, hence again the STA-9s.

As for the SCM 11s, I love the 'naturalness' of its presentation esp. with timbre instruments whilst the LS50s its 'preciseness' esp. with progressive house music and both do well with female vocals, albeit in their own personal way. I tend to alternate usage, depending on my mood.

As mentioned, I am in need of more 'grunt'/power to get the best of of both speakers ( they 'breath' way easier/dynamically, with the extra power as reviewed)
Title: Re: STA-9
Post by: in1unison on 22 Jul 2017, 08:46 am
@ MFM72

My experience with STA-9/DAC-9 combo is quite opposite (Monitor Audio GX 200, BJC LC-1 interconnects, BJC White Ten spaker cables) although I listen to more or less the same type of music you do. Found sound to be too soft and subdued comparing to ST-10/DAC-9 or my old system (Yamaha A-S1100/CA Stream Magic6). Finally settled on bi-amping Yamaha (HF/MF + pre-amp) and ST-10 (LF) using DAC-9 as DAC only.

l guess it just shows how different all of us are in tastes in sound presentation and music perception.
Title: Re: STA-9
Post by: drumnman2 on 22 Jul 2017, 11:55 am
The Absolute Sound review is May /June 2017  if you care to read the review. His bottom line was only recommended if you have speakers with rolled off high frequencies.In the manufactures follow up directly from Jason Lim he states " we have confirmed in our lab that the ls50 does not work well with STA9. The LS50 high frequencies are emphasized by the even order harmonics of the STA9 and sounded harsh. He did however like the ls50 with the IDA-16." Having had  STA 9 for 1/12 yrs I was shocked at the review but don't have LS50's. I would think if anything the highs are a little soft but that's also dependent on the rest of my system. Try them and send them back if you aren't happy. I think they are wonderful for a modest cost with a huge soundstage and a sound you can listen to all day without fatigue. Depends on what type of sound you are after.  Good luck.
Title: Re: STA-9
Post by: MFM72 on 23 Jul 2017, 05:30 pm
The Absolute Sound review is May /June 2017  if you care to read the review. His bottom line was only recommended if you have speakers with rolled off high frequencies.In the manufactures follow up directly from Jason Lim he states " we have confirmed in our lab that the ls50 does not work well with STA9. The LS50 high frequencies are emphasized by the even order harmonics of the STA9 and sounded harsh. He did however like the ls50 with the IDA-16." Having had  STA 9 for 1/12 yrs I was shocked at the review but don't have LS50's. I would think if anything the highs are a little soft but that's also dependent on the rest of my system. Try them and send them back if you aren't happy. I think they are wonderful for a modest cost with a huge soundstage and a sound you can listen to all day without fatigue. Depends on what type of sound you are after.  Good luck.

Though I love the idea of 'auditioning' at home that option is not remotely available where I live, in fact I would have to fly to another country to buy the equipment and as far as I know they do not have any return policy (except for manufacturer defect) hence the dilemma. And there I thought my quest for 'warmth' without the hassle of actual tubes, at a decent price & package has been settled for the LS50s  :duh: ...I guess that's part & parcel of the hobby...so the search goes on...IDA-16  :| aye, but would it be enough, grunt-wise, for the SCM 11s though  :roll:
Title: Re: STA-9
Post by: opnly bafld on 23 Jul 2017, 05:58 pm
IDA-16  :| aye, but would it be enough, grunt-wise, for the SCM 11s though  :roll:

200 watts not enough?  :scratch:

Recommended Power Amplifier:  75 to 300 Watts

FWIW the 5 solid state amps I have used are 50, 70, 150, 100, and 375 watts/ 8 ohms (in order of preference).
Title: Re: STA-9
Post by: MFM72 on 23 Jul 2017, 06:13 pm
200 watts not enough?  :scratch:

Recommended Power Amplifier:  75 to 300 Watts

FWIW the 5 solid state amps I have used are 50, 70, 150, 100, and 375 watts/ 8 ohms (in order of preference).

Looking at your avatar seems ur driving the SCM 11s...do you like it at 375watts or less? I'm aiming for 'optimum' if there's such a thing for it  :green:
Title: Re: STA-9
Post by: opnly bafld on 23 Jul 2017, 06:47 pm
My system is in a fairly large room, but I listen at 80~85 dB average, so the sound quality of amp is way more important to me than watts.

Amplifiers ranked according to sound IMO:
1) 50 (watts/ch 8 ohms)
2) 70
3) 150
4) 100
5) 375

Amplifiers listed according to retail price (lowest first):
1) 100 (watts/ch 8 ohms)
2) 375
3) 70
4) 150
5) 50
Title: Re: STA-9
Post by: MFM72 on 23 Jul 2017, 07:08 pm
My system is in a fairly large room, but I listen at 80~85 dB average, so the sound quality of amp is way more important to me than watts.

Amplifiers ranked according to sound IMO:
1) 50 (watts/ch 8 ohms)
2) 70
3) 150
4) 100
5) 375

Amplifiers listed according to retail price (lowest first):
1) 100 (watts/ch 8 ohms)
2) 375
3) 70
4) 150
5) 50

I do agree with the 'quality' being a priority but due to almost a non-existent of what might constitute as a 'hi-fi' shop in my country, the need to have a-one-all solution in regards to equipment plays an important role in choice of equipment specs, and having ample 'wattage' when needed, say, in the pursuit of better dynamics, power is everything imo (though i cud be wrong), lest I enjoy paying the extra USD$400-500 more ontop of the retail price AND the travelling time (4hrs total by plane), my options though varied takes quite a toll on oneself hence the need to 'have it when needed', if that makes sense...enjoyong this hobby from where I'm at is a bit challenging  :green: but I do know what your getting at, but then again that's my dilemma  :cry:
Title: Re: STA-9
Post by: RafaPolit on 24 Jul 2017, 03:32 am
MFM72, for what is worth, I went through a silimiar dilema and the inability to test the components (albeit with different speakers).

Finally, I decided to go for the near-reference ST-10 to avoid any issues.  It's more money, but perhaps it helps take some of the guessing out of the equation? Of course, the warmth you are seeking for is the signature of the STA-9s, but perhaps the better control of the ST-10 is good enough?

Perhaps searching users with your speakers and the ST-10 would yield success stories you could relate to?

Best regards,
Rafa.
Title: Re: STA-9
Post by: MFM72 on 16 Aug 2017, 07:11 pm
Thought had the perfect amp pairing to drive both of my speakers when I came across NuPrime but I guess it was not meant to be so off to the ever exciting hunt for the perfect amp  :green:
Title: Re: STA-9
Post by: Bill_Bill on 31 Aug 2017, 06:00 am
Just wandering does anyone know what is the peak output current and voltage of STA-9? Thanks!