Review and Measurements of Benchmark AHB2 Amp

[DonH56]

Your reaction is totally overboard to my simple comment. You clearly don't know me or you might think twice about your comment.

I think the response was in general and not to (at) you specifically...

Scott Wurcer, from ADI?

 

[scott wurcer]

I think the response was in general and not to (at) you specifically...

Scott Wurcer, from ADI?

Yes, I don't subscribe to any nonsense OTOH I am totally cool with the SET and full range horn crowd. Whatever enriches someones life is OK by me.

 

[GrimSurfer]

I think the response was in general and not to (at) you specifically...

That's how I read @Sal1950's post too.

I'm a little "past" being cool with whatever enriches somebody's life, as that way of thinking can be used to justify administering cupcakes ahead of medicine. That may not be your intent @scott wurcer but people here are sensitive to people using such thin wedges to introduce all sorts of subjectivist nonsense to the forum.

On the other hand, people here are generally cool with expressions of personal preference.

 

[scott wurcer]

That's how I read @Sal1950's post too.

I'm a little "past" being cool with whatever enriches somebody's life, as that way of thinking can be used to justify administering cupcakes ahead of medicine. That may not be your intent @scott wurcer but people here are sensitive to people using such thin wedges to introduce all sorts of subjectivist nonsense to the forum.

On the other hand, people here are generally cool with expressions of personal preference.

Grim you are.

 

[Xulonn]

Your reaction is totally overboard to my simple comment. You clearly don't know me or you might think twice about your comment.

Welcome to ASR, Scott. I think most people - especially "old timers" - know who you are, and your professional record in audio electronics is quite remarkable as is your participation in the DIY community. I look forward to more contributions by you to our conversations here.

However, there is no need to defend yourself and your ego based on a perceived sleight. Simply call out ASR regular contributor Sal1950 and engage him in conversation. Like most of the science-oriented regulars here, he would likely respond in a civil manner.

As to the original quoted misconception "aesthetic judgement are forbidden on this forum," such b.s. is typical of the whiny statements made here by hard-core audio subjectivists who do not (or refuse to) understand human psychology, psycho-acoustics, and the body of scientific knowledge related to audio. Results of sighted listening comparisons, statements of preferences and aesthetic statements are fine - just don't present them as evidence (proof?) of actual sonic differences, because science-based testing demonstrates clearly that most sighted comparisons are not comfirmable via level-matched DBT.

I have a feeling that the science-literate regulars here would agree that the "holy trinity" (amplifier<>speakers<>room) and their interactions are where the real, audible sonic differences lie.

I am an audio enthusiast and music lover who started his journey with a monaural HiFi vinyl/FM radio vacuum tube system in 1958 when I was also an usher for the Chicago Symphony Orchestra in the Fritz Reiner era. Now, for my twilight years in expat-land with reliable 100mbit internet in the mountains of western Panama, my music sources are digital only - NAS and internet radio. I want my digital components to be accurate, and have low distortion and noise - which I have accomplished on a tight budget. Amp, speakers and room and their interaction are still a challenge, and I suspect that the Benchmark ABH2 amplifier that is the subject of this discussion would drive most speakers - even those that are difficult loads - and minimize the coloration added to the mix.

How do we know if someone auditioning the amp in a home system is reacting to sighted preferences or other psychological factors - or are there actual audible differences based the amp's interaction with his speakers in his room? Without a decent DBT trial, we will never know.

 

[agtp]

Is that true, it would be unfortunate if that was so?

This is a science based website. If your going to present strong opinions on the sound of one component compared to another you should be prepared to back that up with the data from your bias controlled DBT's. Things are a little different here from the audiophool sites where they gush on and on over the sound of $5000 power cables and USB widgets.
Evidence is expected if your opinion is expected to be taken seriously.

Subjective audio claims are perfectly okay as long as you assert that the explanation is an invisible, supernatural, unfalsifiable entity (e.g., Audio Fairy). Sal, and a few others here, accept the supernatural as an explanation, so they have absolutely no argument against it.

 

[Xulonn]

Yes, I don't subscribe to any nonsense OTOH I am totally cool with the SET and full range horn crowd. Whatever enriches someones life is OK by me.

Whew! So you won't condemn me for owning and enjoying a system in the early 2000's consisting of a YBA CD player (France), McIntosh tuner (USA), Supratek tube preamp (Australia), Tektron 2A3 single-ended amplifier (Attilio Caccamo, Italy) and a pair of 100dB sensitive Klipsch Forte II speakers! Truly my most international audio system ever!

I share your audio philosophy - but here at this science-based internet forum, I - and others - will challenge claims of sonic differences that are based on sighted listening sessions and not backed up by DBT.

 

[SIY]

That may not be your intent @scott wurcer but people here are sensitive to people using such thin wedges to introduce all sorts of subjectivist nonsense to the forum.

As someone who has known @scott wurcer well for a few decades, and learned a ton from him, I can assure you that "nonsense" is the last thing you'll hear from him. There's nothing wrong with subjectivism as long as you don't conflate that concept with "wild and unsubstantiated fact-claims." It's a pity that the term has been hijacked.

 

[Sal1950]

Is that true, it would be unfortunate if that was so?

That's how I read @Sal1950's post too.

I'm a little "past" being cool with whatever enriches somebody's life, as that way of thinking can be used to justify administering cupcakes ahead of medicine. That may not be your intent @scott wurcer but people here are sensitive to people using such thin wedges to introduce all sorts of subjectivist nonsense to the forum.

On the other hand, people here are generally cool with expressions of personal preference.

I can only speak for myself but I don't come here for listening impressions and frankly could care less.

How do we know if someone auditioning the amp in a home system is reacting to sighted preferences or other psychological factors - or are there actual audible differences based the amp's interaction with his speakers in his room? Without a decent DBT trial, we will never know.

Grim you are.

Grim, humm that's an interesting response,

Thanks Xulonn, you posted very close to what I had started to type.
Scott, I don't know why you seemed to take my post as a personal attack, I see it simply as a question asked and answered. The internet is full to overflowing with "audio" sites that take some keyboard cowboys drivel about what component X or accessory Y sounds like as gospel without any supporting evidence what-so-ever. Anyone is free to post anything they like but if he doesn't expect to be ask for supporting evidence ??? A member is totally free to say he loves the sound of his SET amp and leave it at that. But if he wants to make a claim that the sound of that amp is more accurate to the source than a ABH2 I promiss you he'll be hit with a bevy of requests for measurement and data to support that statement.
If you want to advance the SOTA in audio reproduction, it will never be done using sighted listening, you need to close your eyes.

 

[Sal1950]

Subjective audio claims are perfectly okay as long as you assert that the explanation is an invisible, supernatural, unfalsifiable entity (e.g., Audio Fairy). Sal, and a few others here, accept the supernatural as an explanation, so they have absolutely no argument against it.

 

[amirm]

Add a truck to that picture and it fully describes Sal.

 

[GrimSurfer]

The problem with our society is that BS is left to propagate for fear of hurting someone's feelings.

I'm ok with people doing their own thing. I'm even ok with them telling us about it. We've all seen how this gets out of hand, however. So when the personal preference declarations end and the value statements/sales pitches begin, that's the time to start drawing the line.

 

[agtp]

View attachment 28001

"The hard core faith healers always end up telling us to shove the measurements up our butts in any case." -Sal1950 LOL!

"But of course when the hoards of believers decend over some fact that shakes one of their closely held delusions, we're expected to shut up and not argue back too strongly. How dare we ask for supportable evidence for any ridiculous claims the believers present. The real problem is our ears or gears of course and you might even get banned for being right." -Sal1950

“Progress can only be made thru a scientific approach to investigation.” -Sal1950

“I’ve often been asked why my responses and attitude tend to have a decidedly "snarky" tone. In reply I've been forced to a declare, when modern scientific knowledge and a lack of common sense fail to have any effect on the deluded and closed mind, All that is left is ridicule.” -Sal1950

“As I've said a number of times here, when all attempts to inject true scientific paths and common sense fall on deaf ears, all that's left is ridicule the wrongheadedness.” -Sal1950

"...a natural outcome of normal human weaknesses and a refusal by them to examine their delusional occurrences in a scientific manner. Reminds me of the schizophrenic that refuses to take his meds because his imaginary friends go away." -Sal1950

“As the saying goes, "you just can't fix stupid”.” -Sal1950

Okay, Sal, I think you see the point. Some of us don’t understand how you think it’s honorable to constantly demand of others what you don’t demand of yourself? No offense and nothing personal. Cheers.

 

[Wombat]

View attachment 28001

The long-standing typo has caused considerable misdirection in US society. The capitalists have always known it to be INGOT WE TRUST.

Which God?

https://undergod.procon.org/view.resource.php?resourceID=000068

Why bless only the USA? A needs basis plea?

Save it for a non-science forum.

 

[LTig]

I think the response was in general and not to (at) you specifically...

Scott Wurcer, from ADI?

@scott wurcer , the designer of the AD797 op-amp which I use in the first stage of my DIY MC phono preamp? It made it much easier to design it. Let me lift my virtual hat !

 

[Purité Audio]

I lent a unit to a potential customer m he had been using a 10watt design, he didn’t like the ‘heavy bass’ the AHB2 produced!
I didn’t hear his system , I imagine the 10 water simply wasn’t driving his loudspeakers properly.
I have sent demonstrated pretty transparent loudspeakers to customers who preferred the colouration of their current set up, ultimately the individual has to listen to it.
As long as they realise the reasons why .
Keith

 

[Daverz]

I lent a unit to a potential customer m he had been using a 10watt design, he didn’t like the ‘heavy bass’ the AHB2 produced!
I didn’t hear his system , I imagine the 10 water simply wasn’t driving his loudspeakers properly.
I have sent demonstrated pretty transparent loudspeakers to customers who preferred the colouration of their current set up, ultimately the individual has to listen to it.
As long as they realise the reasons why .
Keith

The speakers probably have too much bass for the room. I think I hear something similar going back and forth between my Bryston amp and my Rogue tube amps: the Bryston is really strong and controlled in the low bass, but this is not always desirable in a second floor condo. The Rogues have softer bass, which is sometimes easier to listen to. Of course, tone controls would be helpful here.

 

[oivavoi]

Class D proponents of course say no, it doesn't matter.

Those of us who favour completely noiseless High Fidelity equipment might say otherwise. Me, I like my waveforms clean, not fuzzy traces polluted with switching garbage.

That said, not many people listen to square waves or pure sine waves (I do on my bench, but that's me..).

I'd like to follow up on this, hope it's not OT in this thread.

Would you like to chime in on this, @John_Siau ? I noticed that you wrote this in an application note:

Class-D amplifier switching noise can create problems in a loudspeaker measurement system. More importantly, this ultrasonic noise may become audible when it is demodulated by the non-linearities that occur in all loudspeakers. This potential source of distortion may detract from our musical enjoyment. Class-D amplifiers are compact and cheap, but are not necessarily a good choice for a high-end Hi-Fi system.

What I wonder is if this a purely theoretical worry, or whether you have been able measure it? Or heard it in a blind test?

 

[scott wurcer]

you need to close your eyes.

You must be mistaking me for someone else. You better be prepared to back up claims with some sort of controlled DBT. That includes claims of -120dB vs -100dB THD having anything to do with superior sound. I have a place in Leesburg for part of the winter, so I understand the "Florida Man" thing.

 

[GrimSurfer]

That includes claims of -120dB vs -100dB THD having anything to do with superior sound.

Yup. Easy to see where this is going. Scott will try to negotiate superior sound down to a THD of below -80 dB. Then he'll make absurd declarations about his interpretation of the Nyquist-Shannon theorem. That will open the door to the vinyl is superior argument... a necessary precondition to selling MM/MC preamps under the guise of audio superiority.