Hypex nCore vs Class A amps

[waltzingbear]

Do not feed the Borg?

 

[boXem]

I decided I would be a nice guy. Let me enjoy it please, knowing myself, it may not last too long.

 

[ppataki]

I have ordered 2 of Audiophonics PA-S250NC (Hypex NC250MP) amps as I have a 4.0 setup (Nubert nuVero 140 in the front and nuVero 50 in the back)
I have replaced a Crown CT8150 amplifier that I previously had

I must say that it was definitely an "awwwwww" experience when I first listened to these beasts....the sound is totally amazing
It is as transparent as possible, it sounds as clean as I have never heard before
The words "dynamic range" and "stage" have a new definition now: Hypex
Space has opened up in all 3 dimensions but in a scale I still cannot believe
Also it is worth noting that I hear instruments/sounds that I have not heard before - and believe me it is not my imagination playing tricks with me...
Warning: If you are looking for "warm" sound and all that audiophile BS please do not buy these amps as the are fully linear; they will not add any coloration or distortion; they will produce exactly what is in the recording - and that is what a proper amplifier should exactly do!
I have asked Audiophonics to remove the RCA inputs and the input selector switch - which they did
I am extremely satisfied and I would very strongly recommend these amps to anybody looking for a dynamic, linear and transparent sound

 

[ahofer]

Hi,
The main difference I would mention would be: Class AB are quieter than Class D.
It's just an hypothesis. What do you think?

Not my experience. I replaced an Adcom 5802 with p252 from @March Audio . Couldn't tell the difference, and it seems very quiet. I believe the NC252mp S/N is not quite at NC400 level, though.

 

[ahofer]

I just switched from my 3000€ flagship integrated Amp (Denon PMA-2500NE, 25Kg, Class AB) to 2 litlle Monoblocs, NC250MP based, paired with my ADI-2 DAC. (also, an Apollon AS1200 to come)

I noticed nothing what audiophiles are saying. I'm only enjoying very stable and clean power, with no distortion. It doesn't sound better or worse, just as good for a fraction of the price/weight/size. Period.

Exactly my experience (with Harbeth SHL5+ on the receiving end. I A/B'd the March Audio p252 vs Adcom 5802 as fast as I could manage with manual connection changes, with a variety of my music, over the course of an evening. Would love to try with a different amp sometime.

 

[peng]

I just switched from my 3000€ flagship integrated Amp (Denon PMA-2500NE, 25Kg, Class AB) to 2 litlle Monoblocs, NC250MP based, paired with my ADI-2 DAC. (also, an Apollon AS1200 to come)

I noticed nothing what audiophiles are saying. I'm only enjoying very stable and clean power, with no distortion. It doesn't sound better or worse, just as good for a fraction of the price/weight/size. Period.

Just curious, as far as I know, the PMA2500NE is not the flagship. I believe Denon has the 30.2 Kg PMA-SX, SX1 that are their higher end integrated amp.

 

[JohnYang1997]

It's all about implementation. Good class A class AB even under-biased class B will be better than bad implemented class D. Good class D will be better than bad implemented class A even when the class A has more power than class D amp.

 

[Stonetown]

The Hypex NCore 400 measured a S/N of 120 dB. I cannot point to many AB amplifiers that improve on that.

Is 123 dB in 90s Denons Optical Class A series comparible?
POA-6600A monoblock:

• Power output: 260W into 8Ω (mono)
  Frequency response: 20Hz to 20kHz
  Total harmonic distortion: 0.002%
  Input sensitivity: 1V
  Signal to noise ratio: 123dB
  Speaker load impedance: 4Ω to 16Ω
  Dimensions: 310 x 207 x 456mm
  Weight: 15.6kg

 

[Stonetown]

Related to GD things are not really that simple - you may find this measurement interesting. Reflections screw up everyhing in time domain, GD included, and yet it somehow doesn't seem to matter.

Hello! Yes but dont have to be so strange.
Don't mix up: 1)Linear phase (phase shift increasing linearly with frequency), 2)Constant group delay, and 3)Time delay!
All three are actually exactly the same thing.
The problem is distorted group delay, not linear phase = Not all frequencies arriving at the same time.

 

[essence]

I was seeking a nCore amp for a while but then just as I was about to get one the review for the new Purifi modules came out and decided to wait for those to hit mass production instead. But couldn't be bothered waiting so I ended up ordering a Denafrips Hyperion. The stated specs looked too tempting with in house provided measurements:

And based on the same source, it seems Denafrip seems to be under reporting the listed specs.

I hope the price creep isn't too bad for the new Purifi based amps as the costs are slowly approaching used AHB2 territory...

 

[Stonetown]

Anyone compared class D with Class AA from Technics?

Nice to see that todays class D-amplifiers finally have reached the same level as like this one from the early 90s. I had it from 1990 and are still using it. Even still using the built in DAC, made up of 4 pieces Burr Brown PCM56P plus 2 bits of resolution extension. Yes, 16-bit input and 18-bit output via an Yamaha-IC oversampling digital filter, but this vintage digital section is a different story which we are not discussing here.

About the amplifier section: Look especially at the specs for the lower power levels which we seldom seeing specified from amplifier manufacturers. Do we need to replace it with a class D-amp like discussed here in this thread? Have anyone listened to an amplifier with this particular Class AA-patent from Technics, and compared it with an NC-amp or similar? (Or maybe I has to do it myself? )
Cheers, /Per

 

[Willem]

Impressive, other than that it is very power hungry. See here for the contemporary 2x140 watt Quad 606-2 current dumper: http://www.meridian-audio.info/public/606+service+data[3127].pdf I don't think any of these amplifiers have imperfections that rise above the audibility threshold.

 

[boXem]

This heater seems to have pretty good measurements.

 

[restorer-john]

About the amplifier section: Look especially at the specs for the lower power levels which we seldom seeing specified from amplifier manufacturers. Do we need to replace it with a class D-amp like discussed here in this thread?

The issue with the Technics is the residual noise. It's 300uV, which is seriously high for a power amplifier, and with respect to full power the S/N isn't very good. It's only when it's weighted (excluding the hum and harmonics at the low end) does it get remotely close to the class Ds running on an SMPS.

The technics numbers may seem impressive, but it's early in the years when actual harmonic distortion was being separated from THD+N. The 'N' component clearly dominates by a huge margin. On their numbers, the S/N with respect to rated power @8ohms is only 100dB.

 

[Stonetown]

The issue with the Technics is the residual noise. It's 300uV, which is seriously high for a power amplifier, and with respect to full power the S/N isn't very good. It's only when it's weighted (excluding the hum and harmonics at the low end) does it get remotely close to the class Ds running on an SMPS.

View attachment 35740

The technics numbers may seem impressive, but it's early in the years when actual harmonic distortion was being separated from THD+N. The 'N' component clearly dominates by a huge margin. On their numbers, the S/N with respect to rated power @8ohms is only 100dB.

Can you compare that so? Maybe we should consider if the residual noise voltage is measured A-weighted or not? Is it really an issue? Anyway, despite I am driving quite sensitive speakers (96 dB /1,2W) I can't hear any noise at all, even when I put my ear close to the treble/mid/bass elements... From other amps you can hear the noise clearly in my speakers, when listening that close distance, but not from an McIntosh either, and not from a Denon Optical Class A amp either ( I have POA-2400 and POA-6600A, and tested also with a friends McIntosh MA6600, none of the amplifiers having noticable noise even at 1 cm distance)
Is the stated residual noise the only parameter you believe makes the amp unusable? How much is it affecting and how do you believe it would add negative effect to the audio quality?

What about the rest of the parameters? Are they ok?


Cheers,
Per

 

[Stonetown]

This heater seems to have pretty good measurements.

Yes but not so much heat like a pure class A, but a lot more than an SM-amp.

But it is a good bargain we can get, if we are buying the right type of a vintage amplifier, Like these Technics Class AA or probably Denons Optical Class A amps. The latter should be about same low distortion at lower power levels but I might try to measure it to se if it is truth. I believe that is the thing we are gaining with the SM amps; no crossover distortion. The class B-amplifiers crossover distortion is causing the higher THD at lower power levels.

The normal push pull amps needs to run som sort of Class A, to achieve this low distortion during more normal listening (lower power) levels.

Maybe little off topic, but exciting if some of these old vintage amplifiers can compete with a modern good SM-amp like NC. I mean, check the prices!
Interesting thoughts I think, anyway Isn't it?

Cheers, /Per

 

[restorer-john]

Can you compare that so? Maybe we should consider if the residual noise voltage is measured A-weighted or not? Is it really an issue? Anyway, despite I am driving quite sensitive speakers (96 dB /1,2W) I can't hear any noise at all, even when I put my ear close to the treble/mid/bass elements...

There is not a single amplifier I own (and I have an awful lot of them) where I cannot hear the residual hiss when close to a typical tweeter. Some of them have rated S/N numbers >120dB and residuals noise levels <100uV. Even a power amp with a 16uV residual and an 89dB/1W speaker is audible at close range.

The S/N was generally measured with a shorted input or specific value resistance with respect to full rated power.

Maybe little off topic, but exciting if some of these old vintage amplifiers can compete with a modern good SM-amp like NC. I mean, check the prices!

Vintage amplifiers can compete in many areas with modern Class Ds. Class D has brought cheap, plentiful, bandwidth-limited power to the people, whereas previously, the highest power, low distortion, wide bandwidth amplification was the province of wealthy audiophiles.

 

[Stonetown]

Even a power amp with a 16uV residual and an 89dB/1W speaker is audible at close range.

Really? Maybe I don't get close enough to the VLD13 driver because of the depth of the horn itself? Anyway I can hear most amps hissing very distinctly in the VLD13, but not the mentioned Technics and Denon amps. Especially tube amps are noisy, but of course not in a normal distance from the speakers.

The low noise values we are reaching at best are overkill for us but it always feels better when we know the good values regardless of what parameters we are discussing, and in the measurements the later switch mode amps like the NC400, are really nice looking. Looks absolutely beautiful here on Amirms measurements This is way different to some people who talks about things that cannot be specified or measured in audio measurements parameters and whom are not interested in specifications...(like wires, capacitors, mains filtering with DC-blocking etc...blah blah..)

I will compare later with a soft dome tweeter where we are getting really close

Cheers!

 

[restorer-john]

I will compare later with a soft dome tweeter where we are getting really close

Cheers!

I think I have a low tolerance for hiss to be honest. Coming from the analogue era and showing my age- we spent forever trying to minimize noise. Then along came digital and spoiled us, but also highlighted any areas of deficiency.

 

[Stonetown]

I think I have a low tolerance for hiss to be honest. Coming from the analogue era and showing my age- we spent forever trying to minimize noise. Then along came digital and spoiled us, but also highlighted any areas of deficiency.

Yes. Nice when the the analog parts comply with the good digital systems. It was for a quite long time when FM broadcasts was the best audio source in a home, so CDs really made the difference when arrived. Especially Philips CD104 etc, but that is another story Yes btw Denon state for their PRA-1500, 96 dB S/N for the moving magnet (special J-FET) input preamplifier, that is about same as the red book CD 16 bit system, and I cant find those low noise preamps today... Different story and off topic.. Sorry