NuPrime Reference Evolution - a breakthrough product with 1M Ohm input impedance

rustydoglim · « **on:** 19 Jan 2018, 09:47 pm »

The main engineering challenges for Class-D are:

1. Sound tuning - that we already solved with hybrid design using custom crafted Class A transistor circuit

2. Stability and reliability - done

3. switching frequency - as the frequency goes up, it becomes exponentially difficult in design of the amp. In the past 2 years we have been steadily raising the frequency close to 600KHz. Higher freq resulted in more detail and smoother sound. Basically high-end class D amp can now equal or surpass solid state or tube amp, the classification is not the issue anymore, now it is simply who has a better amp.
NuPrime Reference Evolution has achieved a switching frequency of 750KHz. Wow. It is so smooth, fast and revealing.

4. Input impedance - this is a challenge facing all type of amps. If the input impedance of an amp is low, it is harder for the source/preamp to drive it, and the result is distortion. Most good amps on the market have less than 100K input impedance (the famous ST-10 has 47,000 Ohm). Reference Evolution has 1,000,000 Ohm input impedance.
Amps with 1M Ohm are considered so exotic that they are either extremely hard (don't know if one exist today) to find and cost exorbitant amount of money. So when I listened to the NuPrime Reference Evolution in the lab a few weeks ago, I was really surprised by this one change that changes everything I hear. It is hard to describe. Basically everything just sounded better.

That's why instead of calling it Reference 21, we decided to call it the Reference Evolution - it is a breakthrough that no other amp has been able to achieve. It is a mono amp that looks identical to Reference 20 on the outside, but completely difference on the inside.

Shipping early Feb, MSRP $2995 per mono amp.

Wind Chaser · « **Reply #1 on:** 19 Jan 2018, 09:51 pm »

Quote from: rustydoglim on 19 Jan 2018, 09:47 pm

3. switching frequency - as the frequency goes up, it becomes exponentially difficult in design of the amp. In the past 2 years we have been steadily raising the frequency close to 600KHz. Higher freq resulted in more detail and smoother sound. Basically high-end class D amp can now equal or surpass solid state or tube amp, the classification is not the issue anymore, now it is simply who has a better amp.
NuPrime Reference Evolution has achieved a switching frequency of 750KHz. Wow. It is so smooth, fast and revealing.

Have you tried, or do you plan to go beyond 750KHz?

Samac · « **Reply #2 on:** 19 Jan 2018, 11:49 pm »

That is exciting news, Jason. I am really looking forward to the evolution of the Nuprime dac/amp integrateds in general and the IDA-16 in particular.

Keep up the good work, Nuprime.

Cheers,

Scott

slash71 · « **Reply #3 on:** 20 Jan 2018, 12:49 pm »

evolutionary! very intriguing product! hope to hear soon!

Jérôme · « **Reply #4 on:** 20 Jan 2018, 09:34 pm »

Looking forward to buying this wonderful amplifier.
Use my ida-16 as a preamplifier, a good idea?

rustydoglim · « **Reply #5 on:** 21 Jan 2018, 06:35 pm »

Quote

Use my ida-16 as a preamplifier, a good idea?

Yes, and no.
Yes because the preamp is very good, and you will hear big improvement. But this $2995 mono amp is at the highest end of high-end audio performance, there is nothing like this on the market (I heard the last time such an amp would cost > $100K).
No because to get the best performance out of this amp, you should have very revealing speakers, DAC and preamp.

If you have IDA-16, there are two scenarios here:
1. You are just getting into this hobby (a few thousands $ is not that expensive considering what people spend a year for nice dinners, gadgets, or vacation) and plan to build a new system (IDA-16 can be moved to another room). Go for it.
2. You already decided to downsize and don't want the hassle. In this case you should resist the temptation

I sure like to take your money but I always offered my unbiased advice.

Quote

Can we go beyond this in the future?

Sure.

giordy60 · « **Reply #6 on:** 22 Jan 2018, 03:02 pm »

Hi Jason
It is expected to release even the pre ref. 20?

rustydoglim · « **Reply #7 on:** 23 Jan 2018, 08:18 am »

Actually there were multiple R&D projects going on. We evaluated the enhancement of Ref 20 with TDSS/Bob and was planning to release it, but hesitated because it was just a modification. Right then R&D accomplished a major milestone (we know we can do 1M ohm input impedance in the lab, and ultra-high switching frequencies, but research has to make its way into production by solving all sorts of problems) so I got a big surprise when I was in the lab and chief engineer said, "come and hear this".
We are lucky to have this genius chief engineer, he has been a life long tube and solid state amps guy who got into class-d and now hybrid class-d designs. A lot of our amps are very good (ST-10, Ref 20) but to be in a million dollar system (money no object kind of system), they are not quite there. In his view, Ref Evolution is worthy of being in the best system.
I didn't realise how much better it can get until I heard what the 1M ohm impedance can do.

giordy60 · « **Reply #8 on:** 23 Jan 2018, 09:11 am »

thanks Jason

giordy60 · « **Reply #9 on:** 23 Jan 2018, 01:07 pm »

Jason why I do not see the pre ref 20 anymore ?

http://www.nuprimeaudio.com/product-category/amplifier/

audio.bill · « **Reply #10 on:** 23 Jan 2018, 01:27 pm »

Very interesting new amplifier design from an engineering perspective! When will additional details be available on the website? TIA

jeanpapi · « **Reply #11 on:** 23 Jan 2018, 04:45 pm »

Hi, which is the appropriate preamp to use with these amp's? I have the Dac10h/st10 combo with Tdss mods in both of them. Can i use this preamp or i need to change it for something else?
Thanks
Jean.

Wcheng · « **Reply #12 on:** 24 Jan 2018, 03:34 am »

Would this high inlut impedance work well for passive preamps?

audio.bill · « **Reply #13 on:** 24 Jan 2018, 03:40 am »

Quote from: Wcheng on 24 Jan 2018, 03:34 am

Would this high inlut impedance work well for passive preamps?

A high input impedance power amp is ideal for use with a passive preamp since it's driven more easily with lower current demand.

envydd · « **Reply #14 on:** 24 Jan 2018, 03:59 am »

Also I am guessing these will be better than the Hypex NC500 + class A opamp and Icepower 1200AS2 based OEM amps (that seem to be generating some interest) ....

Disclaimer: Am a newbie and would like to be within the intersection of cheap-fi and mid-fi

Loved listening to an old Nuforce amp of mine so I just got an IDA-6 (and happy with the output for now)

rustydoglim · « **Reply #15 on:** 24 Jan 2018, 07:26 pm »

Please do not compare Ref Evolution with Hypex NC500 etc. That's the job of STA-9, STA-6. Or ST-10.
Come on guys, we designed this amp to compete with the best amps in the world, at any freaking price. Bring it on

.

Sorry I went overboard a bit. I have a simple explanation why NuPrime is able to innovate while Hypex and other volume production amp companies don't do (I didn't say they can't)

NuPrime designs amps for its own consumption. Our chief engineer is free to innovate and if the new design costs more, then it goes into a newer model at higher price.
On the other hand, a volume production amp company has to keep its cost low (most of these amp modules are sold way below the retail parts price that you can buy online, at 1000 or 5000 units quantity, it is really really low

). Sure they can innovate, but that's not their business model. They use large OEM factories to make these boards at low cost, and you just can't make 100 to 200 pieces at a time.

It is like buying a burger from McDonald, even if it is their top of the line Angus beef burger, it is still mass produced, not the same as what you can get from a fine restaurant.

rustydoglim · « **Reply #16 on:** 24 Jan 2018, 07:32 pm »

Quote from: giordy60 on 23 Jan 2018, 01:07 pm

Jason why I do not see the pre ref 20 anymore ?

http://www.nuprimeaudio.com/product-category/amplifier/

It is there. I was configuring the website recently and probably something went wrong.
We have some Ref 20 on sale due to the newer Ref Evolution.
The Ref 20 has more power than Ref Evolution, and also the bass might go a little deeper.
If your music preference is the loud and punchy type, you might still prefer Ref 20.

audio.bill · « **Reply #17 on:** 31 Jan 2018, 06:48 pm »

Quote from: rustydoglim on 24 Jan 2018, 07:26 pm

Please do not compare Ref Evolution with Hypex NC500 etc. That's the job of STA-9, STA-6. Or ST-10.
Come on guys, we designed this amp to compete with the best amps in the world, at any freaking price. Bring it on .

Is the NuPrime Reference Evolution on target to begin shipping in early February, and when will additional details be provided on the website? TIA!

envydd · « **Reply #18 on:** 31 Jan 2018, 07:28 pm »

Quote from: rustydoglim on 24 Jan 2018, 07:26 pm

Please do not compare Ref Evolution with Hypex NC500 etc. That's the job of STA-9, STA-6. Or ST-10.
Come on guys, we designed this amp to compete with the best amps in the world, at any freaking price. Bring it on .

Completely understand your logic around mass production and I am happy to see how NuP is innovating with a small team. As an EECS engineer, I am excited to be a NuPrime customer (even though I am not an audiophile).

rustydoglim · « **Reply #19 on:** 31 Jan 2018, 07:49 pm »

Arrrggggg... Sorry, I got confused with the Ref Evolution sample (usually a "gold" sample is made before production) and production release date. The production date is around mid March.