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The Richard Clark "all amps sounds the same" test


Okay, I know there has been tons of commentary on this issue, but I have a specific question. And it will make it clear why I'm posting this amp question in the speaker threads.

I'm curious if anyone knows if Maggie 20.1s or something equally hard to drive and equally transparent has been tested? I know planars have been used on his test, but I don't know any details.

Oh - for those who don't have any idea what I'm talking about see:

http://www.tom-morrow-land.com/tests/ampchall/rcrules.htm
and
http://www.tom-morrow-land.com/tests/ampchall/index.htm

and if you google it there is almost endless commentary on it.

Okay - but I want to test the following:

Magnepan 20.1s
Pass Labs X350.5 or XA160.5
Pass Labs Pre? (Don't care as much)
EmmLabs CD Player

Then, we need a low-cost amp. Now, the trouble is, he has a reasonable request in his test, each amp has to be used within its thresholds, so no using them at 300 watts when one is rated at 30 watts. Obviously with one clipping and the other one not clipping you will hear a difference.

This also applies to a 4-ohm speaker. So, assuming someone hasn't done an extremely similar test and can just tell us the difference, the next question is what is the worst amplifier that is rated at 4 ohms? While the X350.5 is high-power, the test could be done at 85 db, so you don't need too many watts to make that work.

This would effectively answer all the "maggies need high power to by dynamic" and lots of other similar questions. Because the test is at one db level, does one amp really push more bass out of them than another?

Hey - actually wouldn't Tympani IVs be harder to drive? Maybe we should use Tympani's :).

What do people think, is this issue still alive or has someone resolved these issues? I have to think I could hear the difference and may have my wife run some singly-blind tests for me - I don't have any of the equipment above, but do have 3.6s and an Aleph 5. See how that Aleph sounds compared to some sort of $100 amp rated at 4 ohms.

Might there be a 4-ohm rated amp in a boombox or bookshelf system? I'll poke around. Sure a single op-amp chip in a bookshelf system (often what $100 system amps consist of, just a few chips) would sound worse than a Pass Labs Aleph, which Stereophile said compared to the Levinson 300 lb amps?

Oh - and the essence of my idea with this test is that perhaps the sound is 'more similar' on speakers that are easier to drive, but with 20.1s - and this is just as important - with a highly resolving ribbon speaker - the difference might become more apparent.

Oh - also, I'm not sure if he allows me to choose the music, but I have found over the years certain parts of certain passages that show the differences of components more than others. I think that would also be important - what passages are played, as on some I would believe the differences would be impossible/difficult to detect.

If I'm just repeating stuff that can be found elsewhere let me know... Just seems like we should be able to bust this test.
lightminer

Showing 2 responses by shadorne

shadorne's avatar
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shadorne
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I am surprised that this is not generally accepted. My experience is that most good solid state amplifiers which are operated well within their capability (no clipping - i.e. at very modest levels) do sound quite close to eachother - much closer than different speakers. I for one would not be confident enough to pass a test unless it was with a test signal. I don't mean to say amps do not have their flavors - they do but it is definitely, for the most part, what I would call subtle.

In that sense, Richard's test proves nothing to me.

Of course, there are lots of very good reasons to own a high quality amplifier...good music is dynamic, extremely dynamic and it is at those extremes that great amplifiers can and do make a HUGE difference (low and high output levels)...if you want percussion or large band orchestral done well at realistic levels without sounding horrible and harsh then the highest quality amp makes ALL the difference.
shadorne's avatar
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shadorne
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My guess is all these tests were done transistor vs transistor- I'm pretty sure I'd be hard pressed to accurately tell the difference.

I agree - I would suspect the majority of high end car amplifiers are soild state - I would imagine microphonics from vibration might pose a problem with a tube application in that context.

Indeed I was careful to mention "solid state" in my previous remark, as I think you can hear a tube versus SS more easily, especially those with an output transformer - so it would be incorrect to say everything sounds the same. You would indeed be more likely to find slight variations in tube amps due to the voltage paradigm and choice of output transformer (as well as topologies). However, frankly speaking, the test (as described) seems to try to minimize all these aspects too. In short, by limiting amplifier operating range to extremely modest levels (which avoids where most large differences might show up), careful volume level matching, and by trying to compensate for the voltage paradigm through the addition of resistors - it is hardly suprising that remaining differences would pose a challenge to even a discerning listener to score so highly (as Richard requires) when listening to music.
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