Do all amplifiers sound the same? Level matched listening test

[Doodski]

What a sheltered life you've led. Far from all amps sounding the same, there's a massive difference despite what readings might suggest.

First, you need good quality speakers to judge the ability of an amp to get them to sing in such a way as to give you goosebumps. Don't bother looking for an exciting amp if you have drearily dull speakers.

With good speakers, borrow or buy a bunch of amps of Class A, AB, D, SET, OTL, or whatever and spend a few days listening to one and then another. You'll soon realise that not all amps sound the same, despite similar measurements.

An extreme point to illustrate this. I bought a Benchmark AHB2 amp on a rave recommendation and its exceptional measurements to replace SETs I'd been previously using. Instead of listening to music, I found myself listening to Muzak such that I wanted to turn down the volume - kiss of death surely. I bought or borrowed numerous ss amps and listened to each for between a week and a year to establish their worthiness in my system. Some were dire while others excited the soul and neither group was influenced by price.

Over 24 years of working professionally with audio gear and handling thousands of amps with and without switchboxes for comparison of the amps and owning a bunch it became totally obvious that the legend of the amps sounding different was urban rumor and imagination. Yes, if one operates extremely difficult impedance load speakers the amp is critical otherwise not so much. I have heard some colored tube amp stuff that sounded a bit off and different and I heard and owned 2 identical model solid state amps that sounded a bit different although the difference was not really noticeable unless one was looking for it. If you stop peeking at what you are listening to and do proper blind listening tests you will see that what I say is true and stop fooling yourself.

 

[Chr1]

Can you post a link that shows effective use of a tube amp to EQ a speaker, with the frequency response deviation, or some measure of a “voiced amplifier” actually being used to actually improve the response of a speaker in a room? I’ve never seen one example that is even dimly useful.


I can’t figure out what you are saying, your comments are mutually exclusive.

The output impedance of many tube amps is high. This will change the sound, audibly with some speakers. Not in a useful way, unless you are into Rube Goldberg EQ.

Okay. I think that we are now into the realms of semantics. Perhaps I should have used the word "adjust" rather than EQ. My point was that, without DSP we are left with rather crude methods of altering the sound of an analogue system to one's taste. All on a finite spectrum of quality and adjustability. Obviously all way more crude than DSP. With vinyl these include the choice of cartridge, preamp, power amp, plus graphic equalisers and tone controls. And speakers obviously.
They are all rather crude tools/methods for signal prosessing for sure, but tools none the less imho.

As previously mentioned I don't even use vinyl. I do use both DSP and valves however. Not always at the same time. However I don't see them as mutually exclusive.
I also don't see all valve amps as "bad".
YMMV.

 

[Grotti]

What a sheltered life you've led. Far from all amps sounding the same, there's a massive difference despite what readings might suggest.

First, you need good quality speakers to judge the ability of an amp to get them to sing in such a way as to give you goosebumps. Don't bother looking for an exciting amp if you have drearily dull speakers.

With good speakers, borrow or buy a bunch of amps of Class A, AB, D, SET, OTL, or whatever and spend a few days listening to one and then another. You'll soon realise that not all amps sound the same, despite similar measurements.

An extreme point to illustrate this. I bought a Benchmark AHB2 amp on a rave recommendation and its exceptional measurements to replace SETs I'd been previously using. Instead of listening to music, I found myself listening to Muzak such that I wanted to turn down the volume - kiss of death surely. I bought or borrowed numerous ss amps and listened to each for between a week and a year to establish their worthiness in my system. Some were dire while others excited the soul and neither group was influenced by price.

Not this old story again. And not in this thread, please. Pavel has stated clearly that the amps under test measure with a difference of 20 - 30 dB (THD+N) which means lightyears for amplifiers. And still he and others couldn't hear a difference of statistic value. I am abroad at this moment without the ability to listen to the file but given my experience and the trust in at least Pavel's statement I am pretty sure, that I couldn't hear a difference too. Pavels test is of scientific value whereas your statement is strictly anecdotal. I would really appreciate seeing your ABX test report before PMA reveals the DUTs.

 

[TurtlePaul]

Pavel has stated clearly that the amps under test measure with a difference of 20 - 30 dB (THD+N) which means lightyears for amplifiers.

Unfortunately I am away from my system today but suspect I would not hear a difference. It will be curious to see if this is a comparison of an 80 dB SINAD vs. 105 dB SINAD (which I suspect can’t be heard) or a 70 dB SINAD vs. 95 dB SINAD (likely hard to hear but maybe possible?). I do think many here overestimate the audibility of 80 dB SINAD due to the coloring of the charts.

 

[Purité Audio]

What a sheltered life you've led. Far from all amps sounding the same, there's a massive difference despite what readings might suggest.

First, you need good quality speakers to judge the ability of an amp to get them to sing in such a way as to give you goosebumps. Don't bother looking for an exciting amp if you have drearily dull speakers.

With good speakers, borrow or buy a bunch of amps of Class A, AB, D, SET, OTL, or whatever and spend a few days listening to one and then another. You'll soon realise that not all amps sound the same, despite similar measurements.

An extreme point to illustrate this. I bought a Benchmark AHB2 amp on a rave recommendation and its exceptional measurements to replace SETs I'd been previously using. Instead of listening to music, I found myself listening to Muzak such that I wanted to turn down the volume - kiss of death surely. I bought or borrowed numerous ss amps and listened to each for between a week and a year to establish their worthiness in my system. Some were dire while others excited the soul and neither group was influenced by price.

You have been a member here for five years, i just don’t think you have been paying attention.
Keith

 

[MAB]

Okay. I think that we are now into the realms of semantics. Perhaps I should have used the word "adjust" rather than EQ. My point was that, without DSP we are left with rather crude methods of altering the sound of an analogue system to one's taste. All on a finite spectrum of quality and adjustability. Obviously all way more crude than DSP. With vinyl these include the cartridge, preamp, power amp, graphic equalisers and tone controls. And speakers obviously.
They are all rather crude tools/methods for signal prosessing for sure, but tools none the less imho.

As previously mentioned I don't even use vinyl. I do use both DSP and valves however. Not always at the same time. However I don't see them as mutually exclusive. YMMV.

No problem, and agree that semantics is not a good debate!!!

Erin has videos that explore this idea, for example he discusses in his Zu Audio video since this speaker has poor FR and is said to benefit from ‘tube voicing’ by many:

He discusses this about 15 minutes in.

I still have tubes, and vinyl. None of it is useful for EQ. If it was, it would be for a particular pair of speakers in a specific room location. Moving the speakers would be a larger change in FR than the amp's ‘voicing’, rendering any EQ practicality useless.

 

[peng]

I wouldn't think such a poll is worth taking. The wording seems suspicious, does "all amps" mean literally all amps?

If one answers yes, does one mean a low cost amp like the one below would sound the same as a Benchmark AHB2 when driving a pair of popula speakers such as the KEF' rated 4 ohms, producing 75 dB from 2 meters, level matched?

Edit: On my phone for some reason I couldn't tell there was attached files, also, my comments referred to the thread title only, that's why I thought the poll was pointless.

 

[TurtlePaul]

I wouldn't think such a poll is worth taking. The wording seems suspicious, does "all amps" mean literally all amps?

The original post is very careless in this regard. It should be titled: can you hear SINAD. The poster is clear that the main difference in the samples is SINAD. The poll is regarding these two amps. Logic suggests that there is no way that a comparison of two amps can determine if all amps sound the same. And all amps don’t sound the same, there are clearly amps with frequency response anomalies, amps with high output impedances, amps with 1% distortion without clipping (maybe little/no feedback). Regarding you last question, there are some diminutive boxes with blue LEDs from China which perform quite well. You can’t know how that will do unless you measure it, although its 12V power supply will be limiting.

 

[peng]

The original post is very careless in this regard. It should be titled: can you hear SINAD. The poster is clear that the main difference in the samples is SINAD. The poll is regarding these two amps. Logic suggests that tAgreedhere is no way that a comparison of two amps can determine if all amps sound the same. And all amps don’t sound the same, there are clearly amps with frequency response anomalies, amps with high output impedances, amps with 1% distortion without clipping (maybe little/no feedback). Regarding you last question, there are some diminutive boxes with blue LEDs from China which perform quite well. You can’t know how that will do unless you measure it, although its 12V power supply will be limiting.

Agreed, polls like this may be well intended but the results won't mean much. Edit: Didn't realize he compared two specific amps and attached a zip file for tests, so my comments were not relevant, but still, the thread title :

"Do all amplifiers sound the same? Level matched listening test"​

is confusing and misleading, it that was (now I know it really wasn't) the real poll question, then the poll would have been pointless.

 

[Hear Here]

Over 24 years of working professionally with audio gear and handling thousands of amps with and without switchboxes for comparison of the amps and owning a bunch it became totally obvious that the legend of the amps sounding different was urban rumor and imagination. Yes, if one operates extremely difficult impedance load speakers the amp is critical otherwise not so much. I have heard some colored tube amp stuff that sounded a bit off and different and I heard and owned 2 identical model solid state amps that sounded a bit different although the difference was not really noticeable unless one was looking for it. If you stop peeking at what you are listening to and do proper blind listening tests you will see that what I say is true and stop fooling yourself.

I had no axe to grind regarding expectations of the performance of the amps I tested. All were recommended by reviewers or owners of the same speakers or similar as mine, and all passed my check of specs, looks, etc and all were within the budget I had set - £3-8K. Why do you think they should all sound much the same? If you went to a dozen concerts and listened to the same piece performed by well-respected orchestras, would you expect them to all sound the same? Of course not.

Neither of us, I suspect would take measuring instruments into the concert hall - we would listen with our ears and judge each performance for what it is. Why are some here obsessed with measurements to the degree they believe all good-measuring amps will sound the same? If that were so, why should anyone buy any amp other than the cheapest that measures well?

My speakers are about as easy to drive as any, so this should not have put some amps at a disadvantage. I must admit I was surprised at how dfferent these 10+ amps sounded. They were all solid state, but of Classes A, AB and D, yet their class was never an indication of how well they performed ie it wasnt all the Class A ones that offered best performance - it was surprisingly random.

 

[Doodski]

Why do you think they should all sound much the same?

Based on the 24 years of subjective tests and from being a professional employed in jobs where I dealt with audio gear everyday for 24 years plus my education in electronics theory.

If you went to a dozen concerts and listened to the same piece performjed by well-respected orchestras, would you expect them to all sound the same? Of course not.

You analogy is just that an analogy. It has no basis in fact with the matters at hand.

 

[Vladimir Filevski]

...of the amps I tested. ...
.Why do you think they should all sound much the same? If you went to a dozen concerts and listened to the same piece performed by well-respected orchestras, would you expect them to all sound the same? Of course not.

What on earth have amplifiers with orchestras in common??? Brain fart analogy...

 

[Chr1]

"How well they performed"... According To You. In random listening.

ie. Purely subjective.

You are actually missing the point(s) that several people are making now.

 

[Anton S]

...

With good speakers, borrow or buy a bunch of amps of Class A, AB, D, SET, OTL, or whatever and spend a few days listening to one and then another. You'll soon realise that not all amps sound the same, despite similar measurements.

...

Can you categorically say this? Do you rigorously test all of the performance aspects of any two amps that sound different to you? Same harmonic distortion spectra - not just overall THD, but the same levels of 2nd, 3rd, 4th, etc. harmonics? Same slew rates, load variance/invariance, damping factors, etc? If not, I don't believe you can make this assertion.

 

[pma]

Some info about amplifiers under test:

- their frequency response is almost invariant with load impedance, including complex impedance,
- both have output impedance that is low enough (even at high frequencies) to prevent FR modulation by load impedance,
- THD and THD+N (SINAD) are shown below, but these parameters are irrelevant and inaudible unless they are very very poor, like high above 1%. Otherwise, all is masked by the music signal and ear masking. SINAD races are pointless. We need flat unmodulated FR (thus low output impedance with frequency), stable amplifiers without oscillations and stability with low impedance and complex loads.

 

[Anton S]

I had no axe to grind regarding expectations of the performance of the amps I tested. All were recommended by reviewers or owners of the same speakers or similar as mine, and all passed my check of specs, looks, etc and all were within the budget I had set - £3-8K. Why do you think they should all sound much the same? If you went to a dozen concerts and listened to the same piece performed by well-respected orchestras, would you expect them to all sound the same? Of course not.

...

False analogy. Personally, I wouldn't expect the same piece performed by the same artist/group/orchestra performed in the same venue to sound identical to me on two different occasions. Because live performance, eh?

In fact, I wouldn't even expect a recording of any one of those performances to sound exactly the same to me on the same system in the same listening space on any two trials. Because psychoacoustics, eh?

 

[amirm]

the legend of the amps sounding different was urban rumor and imagination.

It was not. See this published report: https://www.audiosciencereview.com/...ts-did-show-amplifiers-to-sound-different.23/

 

[amirm]

Pavel has stated clearly that the amps under test measure with a difference of 20 - 30 dB (THD+N) which means lightyears for amplifiers. And still he and others couldn't hear a difference of statistic value. I am abroad at this moment without the ability to listen to the file but given my experience and the trust in at least Pavel's statement I am pretty sure, that I couldn't hear a difference too.

It is trivial to create test cases where no difference is heard, even when we know audible differences can exist. To wit, in my last job, we commissioned a test of 64 kbits/sec lossy codec against CD rip. The independent lab that we hired ran the double blind tests, showing that some 90% of the population couldn't tell the difference. We got lucky as the lab used classical music which was very easy to encode. If they had picked other material, the result would have been the exact opposite.

Key here is that one has to understand the system's weakness and psychoacoustics, and choose content that pushes that limit of audibility. We have that for codecs and speaker/room testing because work was put in to find such revealing tracks. For things like amplifiers, we don't have such critical tracks but that doesn't mean you just throw one piece of music at it and call it done.

 

[Mikig]

My opinion. My point is: comparing two or more amplifiers depends on the speakers you want to use. It ranges from no difference to a lot.

Each speaker has its own electrical layout and physical characteristics that require proper power to operate within an optimal range.

An amplifier without speakers connected, besides not making any sound, is just a box with buttons and connectors.

In my opinion, if two amplifiers are both adequate for the speaker being listened to, there probably won't be any noticeable differences in the listening experience.

If the two amplifiers are energetically different, and one is adequate for the speaker while the other is not, the speaker's response may be different, and therefore audible.

A specific case I just encountered:
difficult speakers, two different amplifiers, one delivering 130 W into 8 ohms, the other less than 20. The first of the two is adequate, the speaker's response to the ear is always satisfying. Or rather, consistent: rhythm, low frequencies, soundstage.
The second fails to make the woofer work properly, and you can hear it. As the volume increases, the bass goes from lackluster to distorted and muddy at higher levels. You can feel it, you can hear it. It makes a difference in the listening experience.

 

[MAB]

Agreed, polls like this may be well intended but the resuls won't mean much.

Maybe just test yourself and post the results with the verification if you are able to discern difference.

The results are more important than your semantic complaint.