STA-9

pewe · « **Reply #320 on:** 26 Mar 2019, 08:10 am »

Thank you for your reply. Just to clarify: do you mean that one STA-9 is doing a better job than two STA-9 in bridged configuration to a pair with low sensitivity speakers like mine? I'm not that technical but surely a pair of amplifiers in bridged mode is more capable of running difficult speakers? Or am I missing something here?

ST-10M is out of my budget unfortunately. So I'm choosing between two STA-9 or one ST-10. I'm going to use my system for both music and movies in a 2.0 configuration.

I also believe that the ST-10 is a safe choice, it looks like a very fine amplifier, but I was curious to hear what you recommend to low sensiitivity speakers.

RafaPolit · « **Reply #321 on:** 26 Mar 2019, 01:36 pm »

Don't get hung up on the 85db number. Most speakers fall between 85 and 88. The horns have 90+ but that is another niche.

Mine are 87db and deep to 3.8Ohms, and the ST-10 could punch a hole in them with ease. Go for two STA-9 if you want the warmer sound, go for the ST-10 for more neutral sound. Don't worry about power.

You could even go with a single STA-9 and see if you are missing power (I bet you won't) and if you are, go with those second one.

To clarify, no, no one said that one 9 has more punch than two, he recommended two 9s (in modo mode) or two 10Ms.

pewe · « **Reply #322 on:** 27 Mar 2019, 12:27 pm »

Thanks for your input RafaPolit, much appreciated. My gut feeling says I should choose ST-10. BTW, do you use DAC-9 and ST-10 in your own system?

RafaPolit · « **Reply #323 on:** 28 Mar 2019, 05:14 am »

I have the matching ST-10 and DAC-10 vía balanced connectors. I don't have access to the DAC-9.

My gut feeling said the same as yours: the 9s may be enough, but the 10s are for sure going to fit the bill. Without the option to audition them, I decided for the surest bet.

Eisener Bart · « **Reply #324 on:** 3 Jul 2019, 02:36 pm »

Quadro-Amping Audiophilical Perversion

Taken into account that my 2 pcs of Nuprime STA-9 can be switched from stereo mode into mono (and I've tried to do it with great results earlier) I decided to order 2 pcs more.

100% prepayment finally cost me 4 months awating.

Shipper sent my amps to USA instead of Ukraine.
Manufacturer and distributor spent 1 month for investigation.
USA or Ukraine, well, small mistake, right?

Well, I received my wandering Power Amps in good condition. 1 week for standard heating procedure and I've been fallen in the Quadro-Amping Heaven.

Blowing in modest 580 Watts into 1 Speaker got me almost unlimited dynamic and total control of Amps. System shows full absence of sound treatment of the Listening Room.

My review about Nuprime STA-9 still can be found here.

rustydoglim · « **Reply #325 on:** 3 Jul 2019, 08:34 pm »

Happy to hear that you're enjoying your systems. Isn't this amazing that high-end audio is no longer expensive.
By the way, I am not clear about your trouble of sending the amp to USA (for service? Why?).

If you can submit your review to https://nuoem.com/forum/nuprime-brand/ that will be greate. All it takes is 10 min work and you might be selected for free gift or discount coupon.

Eisener Bart · « **Reply #326 on:** 4 Jul 2019, 03:27 pm »

Quote from: rustydoglim on 3 Jul 2019, 08:34 pm

Happy to hear that you're enjoying your systems. Isn't this amazing that high-end audio is no longer expensive.
By the way, I am not clear about your trouble of sending the amp to USA (for service? Why?).

If you can submit your review to https://nuoem.com/forum/nuprime-brand/ that will be greate. All it takes is 10 min work and you might be selected for free gift or discount coupon.

I didn't send anything to USA.
I've ordered 2 Amps from Ukrainian Dealer, shipper sent devices to USA instead of Ukraine.
Ukrainian Distributor spent 1 or 2 month to find out where are Amps.
Simple logistic negligence.

I will submit 2 my reviews regarding Numpire products:
STA-9 http://eisenerbart.blogspot.com/2016/07/killers-of-class-ab.html

and uDSD http://eisenerbart.blogspot.com/2016/09/diminutive-proud-almighty.html ,

thanks you.

Actually I would like to review all Nuprime products, but my Dealer can't assist me with devices.

hnnaum · « **Reply #327 on:** 27 Jul 2019, 08:11 pm »

Hello to all,
can I use Pro-Ject prebox s2 digital as preamplifier for sta-9 or st-10? Its output voltage is 2.05 Veff..
Thank you

JackD · « **Reply #328 on:** 28 Jul 2019, 12:47 am »

Sure you can as you are just using the digital preamp functions available from the ESS chipset. The Oppo Sonica worked the same way. As to how it sounds only you can be the judge. Also that 2 volts gain is at its Unity Gain setting as if you were using it as a DAC only.

left channel · « **Reply #329 on:** 30 Jul 2019, 08:01 pm »

Quote from: hnnaum on 27 Jul 2019, 08:11 pm

Hello to all,
can I use Pro-Ject prebox s2 digital as preamplifier for sta-9 or st-10? Its output voltage is 2.05 Veff..
Thank you

I have used a Pre Box S2 Digital as preamp for an STA-9. No problem. I've driven the STA-9 with other preamps too.

chandlerbing · « **Reply #330 on:** 7 Nov 2019, 11:38 pm »

Hi all,

New to the forum. Found this site while researching about an issue with my STA-9 on Google. I assumed you would like to keep all the STA-9 related discussion in this thread so I thought I'd revive this old thread. Please let me know if I should open a new thread instead.

I have been using a single STA-9 for about a year and I recently got my hands on another one and made them monoblocks. However, I noticed that the sound is off centre when they are in balanced mode, while the sound is completely fine unbalanced.

In order to isolate the issue, I did the following:

Checked all my connections and made sure that they are connected properly. They were.
Swapped the XLR cables to see if it makes a difference. The problem remains and the sound was still off centre to the same side.
Switched back to stereo/balanced mode on the quieter STA-9 and see if it's off centre. The sound/vocal is perfectly in the middle
Played pink noise through the STA-9s one at a time in stereo/balanced mode and measure the sound level. It turns out one of them is 4 db louder than the other.

Does anyone know if there's a way to adjust either the input or the output of the STA-9? (Opening the case or otherwise?) I do realized that there was another member had the same issue a while back, and he fixed it by flipping the mono/stereo switch a few times and it worked for him. Unfortunately it did not work for me and it's greatly appreciated if someone have any suggestion.

Thanks!

slash71 · « **Reply #331 on:** 8 Nov 2019, 11:06 am »

Hi, what preamp you use ..

if the new sta-9 is off centre in stereo mode open a issue , is in warranty time ?

I'm using two sta-9 in mono too, and sound perfect balanced..

chandlerbing · « **Reply #332 on:** 9 Nov 2019, 03:01 am »

@slash71, for BALANCED input, I tried a Nuprime DAC 9 and a GeekPulse XFI and the results are the same, that eliminated the possibility of preamp being the issue.

As I mentioned in my original post, I've tried the STA-9 in stereo/balanced mode and it's perfectly centered. The issue is the balanced input/output of one STA-9 is louder than the other in bridged mode, hence my question about the possibility of adjusting the volume input/output of the balanced circuit.

Thanks.

chandlerbing · « **Reply #333 on:** 12 Nov 2019, 04:28 am »

Hi rustydoglim,

Is this something you can help by any chance?

Thanks!

rustydoglim · « **Reply #334 on:** 26 Nov 2019, 06:31 pm »

Have you created a help desk ticket (go to helpdesk.nuoem.com), once you have log all the info, ask support for instructions to DIY changing of gain. If you don't get any reply in a "timely" manner, response in the ticket to tell them to escalate to Jason.

chandlerbing · « **Reply #335 on:** 28 Nov 2019, 03:42 am »

Thank you rustydoglim. I will create a new ticket soon.

emilk · « **Reply #336 on:** 10 Dec 2019, 09:12 pm »

I just bought two Nuprime STA-9.
But one of the amp is about 5-6 dB louder than the other amp.

This issue is with XLR connection but with RCA cables there is no difference is gain.
Using them in mono config.

I’ve created a ticket and waiting for response..
Seems like something is wrong with these amps.
At least a few of them since I’m not the only one experiencing the issue.

rustydoglim · « **Reply #337 on:** 14 Dec 2019, 09:29 am »

I am aware of your problem, support is on top of this, I think they are asking for photos and serial numbers.

jai1611 · « **Reply #338 on:** 8 Jan 2020, 04:31 pm »

I recently picked up a sta9. Ive got the blue led up front lighting up but no sound. Any troubleshooting to do? The switches at the back set to stereo and unbalanced, which is the way I have it wired up. Tried a different preamp. Should I try the balanced connection?

John Casler · « **Reply #339 on:** 8 Jan 2020, 07:15 pm »

Quote from: jai1611 on 8 Jan 2020, 04:31 pm

I recently picked up a sta9. Ive got the blue led up front lighting up but no sound. Any troubleshooting to do? The switches at the back set to stereo and unbalanced, which is the way I have it wired up. Tried a different preamp. Should I try the balanced connection?

If it is a factory fresh, new amp the first thing to do is check to make sure the "VOLTAGE SELECTOR" is set correctly for your Electrical Power.