Why Audiophonics HPA-S400ET over Benchmark AHB2 or vice-versa?

[Bob101]

Amen.

 

[MaxwellsEq]

There may be a difference in gain, which might make have a practical impact. ISTR, that the Benchmark is relatively low gain, whereas most 1ET400A amps ship with a buffer which allow different gain settings (mine do). If this is the case someone with a preamplifier with relatively low output would find the Audiophonics more practical.

 

[ehabheikal]

Another point, i have deal this audiophonics, they are terrific. I had a defective part, but was in another country, they sent me the replacement without needing to send in the defective part, it was 50euro or so.
I also have the same insides as the audiophinics amp but from another vendor, and i think from mesurements both these amps are totally transparent. They both are above the ability of humans to hear. I will get a lot of heat for my comment.

 

[antcollinet]

I will get a lot of heat for my comment.

Not on ASR you won't.

 

[ehabheikal]

Not on ASR you won't.

ASR is a great place.

 

[ehabheikal]

My question is this: considering how the Audiophonics HPA-S400ET (which I own) measures, specificallY against the benchmark AHB2; is there an objective reason to choose one over another for someone who wants transparent amplification @ power of, say, 100 Watts or more?
Do these amps still have a 'sound'? And if so: is one sounding better (or less good) for certain (domestic) applications?
Why or when should someone go for the Benchmark instead of the HPA-S400ET?

I hope the questions are formulated clearly enough. This is my first Post, so correct me if I'm in the wrong place or redirect me to an older thread about this topic if it already exists.

Save your amp upgrade money for something like better speakers, since both these amps are close to perfect sonically and i think the one you have has more power too the the ahb2.

 

[AweLoi]

I read this quote from John Siau, chief designer at Benchmark:

"The AHB2 is a linear amplifier, but its efficiency is close to that of a class-D amplifier. The difference is that the AHB2 does not produce the distortion and high levels of ultrasonic noise that are always produced by class-D amplifiers. Class-D performance measurements can be deceiving because the measurements are made with a 20 kHz brick-wall lowpass filter that removes the ultrasonic noise. That test-equipment brick-wall filter is missing when you connect your speakers to a class-D amplifier. The ultrasonic noise and distortion are sent directly to your tweeters where they can be demodulated back into audible frequencies. For this reason, class-D amplifiers do not sound as good as the measurements would suggest."

Does this critique apply to the Purifi modules or did Bruno solve this problem?

 

[Purité Audio]

Masters of the disingenuous.
Keith

 

[AweLoi]

Masters of the disingenuous.
Keith

Not trying to be rude but I am not sure what you mean with this comment? Was it an answer to my question in the previous post? Do you mean John Siau is disingenuous or Bruno Putzeys? Both? Or are you perhaps referring to me? I am not english speaking so might be why I am not quite understanding. Therefore my question still stand for someone to answer.

 

[cicastol]

I read this quote from John Siau, chief designer at Benchmark:

CUT

The ultrasonic noise and distortion are sent directly to your tweeters where they can be demodulated back into audible frequencies. For this reason, class-D amplifiers do not sound as good as the measurements would suggest."


Does this critique apply to the Purifi modules or did Bruno solve this problem?

Simply BS.....

Review and Measurements of Purifi 1ET400A Amplifier

Along comes class D. A class D amplifier is already light, compact, an in a reasonable form factor can provide power for virtually all listening conditions, short of a street party. And we don’t need to use old fashioned heavy toroidal transformers. We can use SMPSs. After all, we are in the era...

www.audiosciencereview.com

 

[Bob101]

I read this quote from John Siau, chief designer at Benchmark:

"The AHB2 is a linear amplifier, but its efficiency is close to that of a class-D amplifier. The difference is that the AHB2 does not produce the distortion and high levels of ultrasonic noise that are always produced by class-D amplifiers. Class-D performance measurements can be deceiving because the measurements are made with a 20 kHz brick-wall lowpass filter that removes the ultrasonic noise. That test-equipment brick-wall filter is missing when you connect your speakers to a class-D amplifier. The ultrasonic noise and distortion are sent directly to your tweeters where they can be demodulated back into audible frequencies. For this reason, class-D amplifiers do not sound as good as the measurements would suggest."

Does this critique apply to the Purifi modules or did Bruno solve this problem?

As you can see in Amir's test results, the Purifi

I read this quote from John Siau, chief designer at Benchmark:

"The AHB2 is a linear amplifier, but its efficiency is close to that of a class-D amplifier. The difference is that the AHB2 does not produce the distortion and high levels of ultrasonic noise that are always produced by class-D amplifiers. Class-D performance measurements can be deceiving because the measurements are made with a 20 kHz brick-wall lowpass filter that removes the ultrasonic noise. That test-equipment brick-wall filter is missing when you connect your speakers to a class-D amplifier. The ultrasonic noise and distortion are sent directly to your tweeters where they can be demodulated back into audible frequencies. For this reason, class-D amplifiers do not sound as good as the measurements would suggest."

Does this critique apply to the Purifi modules or did Bruno solve this problem?

In Purifi modules, the utrasonic noise is filtered before the speaker output. The Purifi amp 'only' has a bandwidth of 20kHz, and then drops off. I don't know how the 'RMSlevel(dBrA)' on the vertical axis translates to 'regular' db attenuation, but -5 at 50kHz I expect to be plenty. No cheating needed in testing, unless you call Amir a cheater

There might still be class D amps around that don't bandwidth-limit their output, but I think most half-decent manufacturers have got the message by now.

 

[AweLoi]

As you can see in Amir's test results, the Purifi

In Purifi modules, the utrasonic noise is filtered before the speaker output. The Purifi amp 'only' has a bandwidth of 20kHz, and then drops off. I don't know how the 'RMSlevel(dBrA)' on the vertical axis translates to 'regular' db attenuation, but -5 at 50kHz I expect to be plenty. No cheating needed in testing, unless you call Amir a cheater
View attachment 389908

There might still be class D amps around that don't bandwidth-limit their output, but I think most half-decent manufacturers have got the message by now.

In this review of the Purifi modules, https://www.audiosciencereview.com/...easurements-of-purifi-1et400a-amplifier.7984/, Amir seem to confirm that there is ultrasonic noise. He is talking about baseline noise which I have no idea what it is or if it is relevant in this discussion.

Quote from the review below:

The Benchmark AHB2 maintains its less noisy baseline but as we reach full power, the 1ET400A catches up to it and keeps going with more power.

Distortion+noise versus power and frequency yields this (with pre-gain stage on):

I was surprised to see the rise in distortion with frequency. I had hoped that the super high gain-bandwidth of the 1ET400A would do away with this. Not an audible concern though as the distortion products here are all in ultrasonic range.

 

[Bob101]

In this review of the Purifi modules, https://www.audiosciencereview.com/...easurements-of-purifi-1et400a-amplifier.7984/, Amir seem to confirm that there is ultrasonic noise. He is talking about baseline noise which I have no idea what it is or if it is relevant in this discussion.

Quote from the review below:

The Benchmark AHB2 maintains its less noisy baseline but as we reach full power, the 1ET400A catches up to it and keeps going with more power.

Distortion+noise versus power and frequency yields this (with pre-gain stage on):

I was surprised to see the rise in distortion with frequency. I had hoped that the super high gain-bandwidth of the 1ET400A would do away with this. Not an audible concern though as the distortion products here are all in ultrasonic range.

You are right, and I shouldn't trust on my selective memory alone when replying
Amir stating it as 'inconsequential', is why I stopped worrying, and learned to lave class D.

 

[AweLoi]

You are right, and I shouldn't trust on my selective memory alone when replying
Amir stating it as 'inconsequential', is why I stopped worrying, and learned to lave class D.

You are probably right. Bruno Putzeys seem like a really competent engineer too.

I actually already own the Audiophonics hpa-s400et and it sounds very good to me but I have not compared it to a high end class a amplifier though. I have compared it to a Classé ca-2100 AB amp and I could not really tell the difference to be honest. I thought there perhaps was a small favour towards the Purifi but really hard to tell when you need to unplug and plug in and then level match. To much time in between.

 

[Bob101]

You are probably right. Bruno Putzeys seem like a really competent engineer too.

I actually already own the Audiophonics hpa-s400et and it sounds very good to me but I have not compared it to a high end class a amplifier though. I have compared it to a Classé ca-2100 AB amp and I could not really tell the difference to be honest. I thought there perhaps was a small favour towards the Purifi but really hard to tell when you need to unplug and plug in and then level match. To much time in between.

I use a Dynavox AMP-S MkII to switch between amps. It's a passive no-nosense device. 12 banana plug inputs at the back (designed for switching between amps on one pair of speakers, you can just as easily use it as a speaker selector: the thing doesn't care). 12gauge wiring inside and one very big, solid rotary switching knob at the front. If it adds distortion it's not the amount I can hear or care about. It lets me switch between level matched amps almost, but not really instantaniously. The unavoidable middle position of the knob is 'off'. No signal goes anywhere. And to switch from amp1 to amp2, there is a unavoidable moment of silence as you have to pass the middle position. I just turn the thing real fast
My experience: all amps sound different, but driven within their normal operating range all well-designed amps do the exactly the same. Some are tighter, brighter, punchier, harsher, but after fifteen minutes of listening to material I am not intimately familiar with in my 'average' living room (a tasteful mixture of reflecting and absorbing surfaces, not specifically acoustically treated but with combined well-considered speaker and sofa placement) my ears just accept the sound of amp2 as the new normal.
I love love listening to music, but I just as much like to use music to listen to my gear.

 

[Waxx]

Another point, i have deal this audiophonics, they are terrific. I had a defective part, but was in another country, they sent me the replacement without needing to send in the defective part, it was 50euro or so.
I also have the same insides as the audiophinics amp but from another vendor, and i think from mesurements both these amps are totally transparent. They both are above the ability of humans to hear. I will get a lot of heat for my comment.

Audiophonics (and most boutique brands that live on reputation) have a good support, but so does Benchmark. I worked in studio's before and benchmark is a known brand there with pro support with a good reputation (long before they went into hifi). They started as a supplier of custom equipment for the broadcast industry in the 1980's. I also thought the company is still owned by the original owners, not sold to an investment funds or a large multinational.

 

[Waxx]

I think once the sinad is higher than 96dB, it becomes irrelevant and other factors come into play. Both amps are so good on neutrality (the ASR standard) that the only factors are how powerfull it is and asthetics/functionality/branding. For the rest they are equal in real use (altough they measure slightly different) and should not have a sound. Even my cheaper NCore NC122NC board based amp get to that poiont (but is only 75w/8R and in a very bland case).

 

[Purité Audio]

At one point we had Hypex/Purifi ( both March Audio at that time) and Benchmark I couldn’t hear any difference between them all fine amps.
The Hypex did get quite warm the Purifi modules ( Boxem now) are cool, ( aesthetics and temperature).
Keith

 

[walt99]

I run AHB2 for LCR and Hypex for surround, but the Benchmark is something I consider as an end game amp, the Hypex is budget friendly for 8 channels surround speakers but I consider it almost as a throw away amp. I think of the Benchmark as the industrial version of McIntosh, solid product made in the USA from a great company.
I would never consider replacing the Benchmark with a purify.
I would prefer an 8 ch purify to the 252 Hypex but the price/availabily for those are quite high.