AudioCircle
Other Stuff => Archived Manufacturer Circles => NuForce => Topic started by: rustydoglim on 18 Dec 2006, 02:38 pm
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[This an updated posting. The measurement result was better than anything else on the market at any price :drool:]
I will post more information on the website but here's the summary. We have listened to early production P-9 last week and totally impressed. P-9 is expected to retail for $2950 and it will match the performance of Mark Levinson No.326S $10,000 (yes, we have this preamp in our lab to do AB comparison). The software still need some revision (some cool features such as the motorized Apls volume pot will slowly go back to its previous position when power on!). Some distributors and reviewers will be getting them in January but customers will get the volume shipment starting from end of Feb. This is a major break-through from Nuforce. By the way, we can't claim all the credit. The core of P-9 is designed by Demain Martin. We did the integration.
[I removed the summary and spec since the website now provide the latest update]
http://www.nuforce.com/products-preamp.htm (http://www.nuforce.com/products-preamp.htm)
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Outstanding news Jason! Looking forward to upgrading my P-8/Ref9's to P-9/RefSE as soon as humanly possible. Can you provide a few pix of the new units?
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yea jason, how about some pics. aa
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Will have pic in another day or two. We're waiting for photo from the studio.
0.0004% THD+N, Zero phase shift. Very scary. Click on the link on P-9 product page to see the plot. Show me another preamp that come close to it :). Wait till you hear it at CES 2007.
Well, for those of you who doesn't know Demian Martin, read his brief profile on our product page.
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(http://www.nuforce.com/gallery/P-9-gallery-small.jpg)
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Are the 3 power supplies SMPS or linear? Thanks!
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hey jason if it sounds as good as it looks, you will have another winner, thanks for the pics,
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Are the 3 power supplies SMPS or linear? Thanks!
The audio stages are powered by 2 separate linear supplies. In our CES demo, we are using an SMPS for the logic supply, although we may change it to a linear for production.
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Take a look at the plot http://www.nuforce.com/plots_p9.htm (http://www.nuforce.com/plots_p9.htm)
No other preamp in the world can handle a 125KHz square wave input as clean as P9.
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Jason,
How much gain does this unit offer ?
Michael
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Take a look at the plot http://www.nuforce.com/plots_p9.htm (http://www.nuforce.com/plots_p9.htm)
No other preamp in the world can handle a 125KHz square wave input as clean as P9.
Why do you want to pass 125k square waves, ie what does the output of your companion power amp look like with realistic loads at full power if you do?
thanks
steve
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Jason,
How much gain does this unit offer ?
Gain is 5dB. It can be adjusted up to 20dB of gain (factory option).
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Take a look at the plot http://www.nuforce.com/plots_p9.htm (http://www.nuforce.com/plots_p9.htm)
No other preamp in the world can handle a 125KHz square wave input as clean as P9.
Why do you want to pass 125k square waves, ie what does the output of your companion power amp look like with realistic loads at full power if you do?
thanks
steve
That's what it takes to preserve music's transients.
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Take a look at the plot http://www.nuforce.com/plots_p9.htm (http://www.nuforce.com/plots_p9.htm)
No other preamp in the world can handle a 125KHz square wave input as clean as P9.
Why do you want to pass 125k square waves, ie what does the output of your companion power amp look like with realistic loads at full power if you do?
thanks
steve
That's what it takes to preserve music's transients.
I don't know what source you might be using, but what would your companion power amp look like with realistic loads at full power if you do?
thanks
steve
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Why do you want to pass 125k square waves, ie what does the output of your companion power amp look like with realistic loads at full power if you do?
THD, phase-shifts, and bandwidth limitation are cumulative, so a preamp that does not corrupt music would be ideal, and P-9 is Nuforce's attempt to accomplish the goal of 'a straight wire with gain'. Indeed when the preamp 'no longer matters', then the limiting factors in the music reproduction are now the loudspeakers and the power amplifiers, these are no yet 'a straight wire with gain', as of today, but surely we are working towards that goal.
You can refer to the measurement plots of Nuforce amplifier published on our web site.
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Casey,
Considering that the P-9 is a two chassis design, do you think it would be possible to include a DAC with a couple of digital inputs? The AVP 16 has a preamp and a DAC section and that price point it is unbelieveable IMO. The P-9 with a great built in DAC would be a killer combination.
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can anyone who has a p-9 up and running in there system give some feedback on your thoughts, and comments, i have ref 9ses and its seems like a no brainer to add a p-9, any replies would be appreciated, thanks
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P-9 has been in field testing with 8 distributors around the world at trade shows and dealers visits during the past few weeks. It was also sent to an indpendent lab/review. The comment was that the spec is the best ever measured and the sound is world class. I will publish more plots when I get the chance.
During the field testing, we found some minor bugs and will be sending the revised units to distributors again for qualification. P-9 will likely ship to dealers around Mid March even through we are producing them at end of Feb. We want to ensure a perfect release of this world class preamp.
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ok jason thanks for the update, have been using a marsh tubed preamp lately, and will sure try the p-9 when available, mike
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Sadly not balanced ?
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well with the help of john at summit audio boxed up my p-8 today and sent in to nuforce for the p-9 upgrade. looking forward to the fine looking p-9, will give updates
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(http://www.nuforce.com/gallery/P-9/P9-Copper1.jpg)
(http://www.nuforce.com/gallery/P-9/P9-Copper2.jpg)
(http://www.nuforce.com/gallery/P-9/P9-Silver2.jpg)
(http://www.nuforce.com/gallery/P-9/P9-Black3.jpg)
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Knowing how good the P-8 is makes it really interesting to get the P-9. I have pretty high expectations :) It looks very nice too, well done.
Regards,
Karsten
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Got the P-9 today, has been breaking in for 6 hours so far. I like the direction it it seems to be heading. Very transparant, fast and dynamic. Just the virtues i like in a preamp. Way to go NuForce :thumb:
Karsten
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great karsten, hows the remote, sounds like early thoughts on p-9 or very good. keep us updated, thanks mike
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Beachbum,
The remote is really cool, I like it a lot. It is hard to describe but I think NuForce will post a picture soon, otherwise I can mail you one.
I just did some serious listening for a few hours. You have something to look forward to :D I can say with confidence that you cannot possibly imagine how good it is......
Karsten
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hey karsten, what amps are you using with your p-9, also is the volume control step ed with a wide range, thanks mike
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Yes, I'm contemplating the Nuforce amps, but can't decide on the 9.02 or the 9.02SE. Everybody would like the SE's but how do you decide who would be happy with the non SE version?
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hello tyee, i will give you my experience with ref 9, and the SE version, i had the first ref9s in my system for a good nine months and the amps were very detailed and put out a fine stage, they give my wife and myself a lot of music sessions with great enjoyment, when the nuforce gang improved the ref 9 to the SE version, i had my sights set on upgrading,
nuforce service was super fast and i had my amps back in less than a week, the SE version goes deeper into the music, gives micro details and is a super amp, in my case it was a good upgrade as my system fell right into it, both amps have no problems driving my tyler signature system speakers,
now i am going the upgrade to my p8 preamp, and really looking forward to what p9 is all about, good luck and happy musical days, mike
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hello again karsten do you stack the two p-9 components like the pictures from nuforce, or you using any type of isolation under them, and curious about the connections between the two, thanks mike
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Beachbum,
The volume steps seem fine enough to me, but I guess that people with high effiency speakers may find step 1 too high. The SP Tech Revelations I'm using are 91 db (4 ohm) and step one is just on the border of being too loud as lowest level.
I'm using it with a set of Ref 9 SE.
I have placed them next to eachother on a little plate in my Starsound Sistrum Rack. They are connected to eachother with high density sub d connectors. Looks pretty much as a short VGA cable.
Break-in is still doing small wonders here...... :)
Karsten
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thanks for the answers and keep us updated as breakin goes on, i am in a waiting pattern with mine hopefully soon, thanks again karsten, and have a good one, mike
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The best way for placing P-9 is to put the two units side by side. The transformer is very quiet. But we all know that audiophiles pick on everything.
I think Beachbum will have to wait for 2 more weeks before he can listen to P-9. If my memory serves me right, he ordered a silver color P-9 and it is all sold out. :duh:
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hello Jason and thanks for the bad news, go figure i would have the one out of stock, good things come to those that wait, i always have my back up marsh p2000t thank goodness, to be with out music now that would be a bad thing, thanks for the update Jason and if possible let john know or email me a tracking number when shipped, and keep the fine equipment coming,
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Hopefully black is not sold out too!
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Thanks for all the interests on P-9. We recommend keeping the 2 boxes side-by-side, and for the most logical wire routing, put the Analog Box on the Left, and Control/Power supply Box on the Right, you will notice that the smallest incoming signal is furthest away from the AC power inlet, and wire-crossings minimized.
However, the locations of the circuit boards and the transformer are well thought out, so there has been NO MEASURABLE performance variance when stacking the 2 boxes. aa
Make sure you use P-9 with the included AC cord (the same AC cord supplied as with Ref9 and Ref9SE). The extra high bandwidth means the AC cord for the P-9 should have a level of RF and noise rejection.
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My SE's arrived this week as an upgrade to my 9.02s. P-9 arrives Friday (upgrade for the P-8), the same day my visiting folks depart for home. Freeing up what looks to be one heck of a break-in / upgrade weekend! Reviews to follow...
Though, I plan to use my own AC cords, opposed to what Casey recommended. Hopefully this is OK. I currently use a Zu Audio Bok for the P-8 (and soon P-9), and Harmonic Pro AC 11's on the Ref 9's (and soon for the SE's.)
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hey stingfan i cant comment yet on p-9, but i can tell you that you are going to love ref -9 SE. they will go through changes until broke in, but for me it was fun to hear the differences in break in, good music listening ahead,
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The volume steps seem fine enough to me, but I guess that people with high effiency speakers may find step 1 too high. The SP Tech Revelations I'm using are 91 db (4 ohm) and step one is just on the border of being too loud as lowest level.
Karsten
This is my first impression as well. I have Zu Druids mk4's which are 101db sensitivity and step 1 is also right on the edge of being too loud. What's more, subsequent volume steps are not the same step up decibels. Let me explain:
There are 100 digital steps on the Control Box read-out from 0-MAX on the P-9. However, the first 13 steps are huge volume jumps each. At level 13 out of 100, the analog ALPS pot dials ups up to the half way point-- bad user interface here IMHO. At the halfway point on the ALPS (12 o'clock on the dial) I would expect to be at volume step 50, not 13. And further, as you get dial up past 12 o'clock, the decibel steps get increasingly smaller. Its almost a logarithmic step function. This may not make sense or be all that user friendly to our fellow hi-fi'ers. I much prefer a linear volume step function, as that of my old P-8 volume steps. Though the P-8 was almost too much in the other direction with the steps being slightly too small, even for the Zu's. At low volumes it is especially important to have the most subtle control over volume. I hope Nuforce chimes in to explain and resolve w/ the P-9.
When using the ALPS dial manually you **can** indeed get much more sensitive volume control. But that means you have to physically walk up to the unit to adjust each time. Not good if the P-9 is controlling your tv/dvd as well.
I am curious and surprised that none of Nuforce's professional beta customers spotted this before full customer ship. It is the most glaring aspect of unit, since volume control is one of the most visible user interface aspects of a pre-amp. Hopefully this is addressable in some easy way.
The rest of my review, on sound quality, to follow once I've had a fair listening session today.
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Repost from another topic about the volume issue:
With P8, the digital volume control is not as 'pure' device as the passive Alps pot, and the primary goal for electronic volume control (as in the P8) is it's very easy to use software to dial-in exactly the volume level, and there are 200 steps available.
The challenge with P9 is that we have exactly 1 rotation on the Alps pot, as limited by its physical form. Compare this to the equivalent of "20 turns" (equivalent) on P8 volume.
One point that I want to make is that human hearing is 'logarithm' in nature, and on P9, we decided to simply divide down the 1 rotation into 100 steps, as the Alps port is logarithm in nature, display=50 not necessary means a 12'o clock position on the analog pot, but rather, the Alps port gain is at the 50% level in dB scale.
We are tracking the voltages electronically and not memorizing the physical position.
- Casey
I will add that using the Apls volume pot allow us to achieve pure analog volume control without the expense of using banks of expensive resistors and relays (that will double the price of P-9 :)). The result is superior performance as evident in the spec. The drawback is the integration with digital volume remote and the Apls volume pot. I think after a while, you'll get use to it :). The alternatives are not good. Pure digital solution degrade performance. Array of resistors banks (traditional high end approach) will bring the price of P-9 to $10,000. So, I think at US MSRP $3150 for a best performing preamp in the world, this is a good compromise in value for money :)
- Jason
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Excellent point. So in my estimation, a key factory update for the P-9 would be, via software: Resetting the digital-to-ALPS volume interface as follows: 100 steps of **equal** gain all the way around the ALPS dial should do the trick, with 0 being silent and 100 = 100% gain. Agree?
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The Alps port only comes with Log-scale Audio steps only. Alps does not make a linear pot (useful in adjusting voltage) with a motor control.
The following chart shows the various difference scales used in potentiometer:
(http://sound.westhost.com/pots-f4.gif)
With Audio-taper potentiometer, 50% half-way point actually is 1/10 of the full wiper range (i.e. total resistance), i.e. for a 10k pot, 50% is 1k.
Supply Voltage= 1.0 Volts
Pot's Total Resistance = 10kOhms
Position (0-100%)=50%
Wiper Voltage (Linear)=0.5Volts
Wiper Voltage (Logarithmic)=0.11Volts
Further reading: http://tangentsoft.net/audio/atten.html (http://tangentsoft.net/audio/atten.html)
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Yes, thanks for your chart etc. But you have misunderstood me. The Alps POT is NOT in question here. Using the Alps dial manually works great, and I'm fine with its log based steps. Lets be clear there are two "steps" we are talking about here: Alps steps and your digital volume controller display steps. Two very different things.
The problem is in the P-9's electronic volume controller that interfaces with, and controls the Alps pot motor for motorized (not manual, hand turned) volume adjustment. When # clicks = 1 and display = 1, you send a signal to the Alps motor to rotate the POT certain distance around the dial. Let's say for display volume step 1 it rotates the POT roughly 12 degrees on the dial. You can easily tell the motor not to travel such a long distance for display = 1. This has nothing to do with the Alps. Because I can manual dial/adjust the Alps dial in much smaller increments than your controller is moving it, and get much more precise volume adjustments, which means the solution to this resides in tuning your digital volume controller. For example: reprogram the digital volume controller display=1 to equate to moving the Alps motor only say 6 degrees around the dial instead of 12. This very different from the actual Alps steps which are fine when manual dialing volume with the Alps. The problem is not the Alps, nor its own steps itself. Does everyone understand this now? :)
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sorry to hear your volume control problems stingfan, and knowing the nuforce gang i am sure they will work it out, are you getting much music time. whats your thoughts on the audio secton of the p-9?
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Oh for sure. I think part of the frustration simply stems from trying to explain a complex problem in email or a forum. This one is particularly hard, given both the price and the top billing for the P-9. Mostly because I am getting the impression that these 'artifacts' ma As there are a zillion Alps-based pre-amps out there, and they all let the remote control directly control the Alps, making fluid, limitless volume control. Why would someone pay $3k to have such imprecise control over volume?
Hardly any air time with the P-9, other than when I switched back to the P-8 (with zero problems with my XLRs) did I hear a noticeable downgrade in resolution, clarity, and detail...I was not even formally paying attention to the music when this difference practically hit me over the head. I decided it would be harder to judge it fairly until my 4 other issues are addressed. Its deliciately placed back in the box, and going to Milpitas tomorrow. Hopefully it doesn't get scratched in the repair shop. I'm very particular about this. My old Ref 9's probably look better than they did when I bought them.
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stingfan call nuforce by phone, they have always been able to answer my questions,
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We lowered the gain on P-9 for Stinfan. The noise that he reported is always there in his system. I beleive Casey worked with him to get rid of the noise (not related to Nuforce equipment).
As the alps motor turns, there is a very small (I have to put my ear to the tweeter to hear the very faint sound) noise but it becomes dead quiet when it stops.
Anyway, the P-9 is back to Stinfan and we'll hear from him next week. We did not find any fault with his P-9.
Using the digital volume to control the Alps motor is tough to make it perfect (ie as smooth as manually turning the Alps pot). We understand Stinfan's point. I guess we're asking customer to get use to it as a compromise to the superior sound of P-9.
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My interactions, test sessions, and discussions with Casey were long, thorough, and quite enjoyable. Definitely upholding the Nuforce reputation of their commitment to quality, performance, and service. We learned many things through our exchange. Yes, some minor things that I will have to live with as Jason points out, in exchange for the best sound. I have 101db sensitive speakers, far more efficient that the S-9's used to test my P-9 back at Nuforce. So indeed my speakers will be far more revealing of any residual noise or other artifacts.
Indeed together with Nuforce, we found some removable noise coming from the HDMI of a couple of my sources, but it was only with the P-8 in the system thus far, while P-9 at their lab. We have not yet concluded the noise was/is solely from the sources, but we sure hope this is indeed the case! :)
Jason left out one very fascinating fact I learned from Casey regarding the non-uniformity of the *motorized* movement of the Alps pot. The reason the motorized dial travels so far for the first 1-10 steps displayed on the P-9's digital controller display and then much less so for say, steps 30-50 has to do with the resistance on the Alps. The best sound, as Casey explains, comes when there is minimal resistance on the signal. The resistance on the Alps goes down as you turn up the dial, or when the dial is 'opened' up all the way. So apparently the ideal minimal resistance position, or "sweet spot" for the dial is between 12-3pm (closer to 3pm) To achieve this, the *digital* steps are set to manage the motorized alps movement scale in such a way as to get the "ideal" listening volumes to align with the dial in the 12-3pm. By universally lowering my gain in some special way (different than described earlier in this thread) we enable my system to get to 3pm on the dial without shattering the windows in my loft. Should be quite interesting to see the results. Unfortunately, I have to fly to east coast for mtgs all next week, so I won't be able to test until Sunday of next week. Stay tuned!!
Final Disclaimer:
I am a product designer by profession, as such, my design-related and usability issues with the system stem from my ruthless attention to detail that often goes well beyond most prosumers, and even audiophiles in this department. This explains why you'll often see quite a bit of colorful feedback in this regard, in my postings here.
I really appreciate Nuforce's approachability and time commitment to one small customer such as myself. It is what makes the different between really good companies and really great companies. More on this story to follow!