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
Oem - I think your point about Carver actually possibly supports what this guy is saying. Remember, the premise here is that he will use an EQ in front of one amp to make it sound like the other to eliminate soft top or bottom ends. He agrees that some amps are softer or stronger on top or bottom end etc., and says that this is not the main thing people are saying is better or worse about amps - he says other people are saying there are other aspects of amps that are better/worse in sound quality other than what can be adjusted with an EQ.

Anyway its just a few hours (hopefully) to conduct this test this weekend, so here goes. And of course, I'm not going to frequency EQ the 2 amps like he would, but at least I want to make sure I can hear the difference between the stock forms of 2 amps.
Soundlabs are probably better for this as they are rated at 8 ohms, then I could very easily get a $40 amp versus the 4-ohm rated ones which are of higher quality.
hi lightminer:

what differnce does it make if you do or do not detect differences ?

people will still buy amp a instead of amp b, regardless of the outcome of this test.

at best it is an academic exercise. at worse, it is a pointless exercise.

this test will have no affect upon purchases of components.
Mr T., what if the veracity of the claim was demonstrated TO YOU beyond doubt, such that the only conclusion you could draw as an intelligent and reasoned person, is that the differences you thought you heard all these years were an illusion? Beyond any shadow of a doubt.
Agreed overall. Maybe an extremely minor impact. But, I like academics! And I do have the belief that if we all have similar logical patterns and similar data people should generally eventually come to the same conclusions - I know I'm a hopeless philosophical optimist in that way, but I enjoy life from this perspective more. I am very aware it rarely happens in real life.

Okay - so I found the perfect amplifier. (Well - this is in the 8-Ohm region, but useful for reasons you will see nonetheless. The Onkyo is still the lowest budget 4-ohm I can find.) It is called the "iSymphony Micro Music System". It is 29.99 and has a whopping 14 watts, and weighs about a fourth of a pound.

At 85 db sensitivity for my 3.6s, If I calculate right, that gets me to around 96 db - not precise calc, but close. Plenty loud!

Then, sitting in Radio Shack holding this thing in my hand, I thought about something. First of all, of course this thing will stink up my living room with its sound at 96 db. Actually - what would be really fun is to see if I could melt it after 4 hrs of 96db playing. Okay - but I was thinking. And this relates to the requirement I am imposing to use Maggies for the test. Again, we have to remember what he is saying very specifically:

9. The amps will not be overloaded during the session from either a voltage or current requirement.

The trick about electrostatics is that they are hard to drive. So if he is going to hook up electronics to the cheap amps to see when they are overloaded and say 'its overloaded, you can't run it this loud' because he is working with the real watt number vs published and it is far less - in this case maybe 4 watts per channel instead of the claimed 14 (14 might be both channels, so that is 7, then lets say they overestimated by 2x), and then with Maggie 20s or 3.6s we end up at some super low db, and I can barely hear the music let alone differentiate it, then that might be the thing!

Megabuck amps don't overload as easily. Even Pass Amps - take the XA100 vs XA100.5 - the 100-not-point-five was an 8-ohm amp and didn't double down into 4 ohms. The 0.5 added that, if I understand correctly by adding output devices to support the increased low-ohm load. So even the 100 vs 100.5, on a 2-ohm or 4-ohm speaker driven really hard should sound different, let alone compared to a 29.99 receiver. The Aleph 3 was tested by Stereophile as stable into 1-ohm and lower loads.

Okay - so this is somewhat interesting. The use of his challenge/research into these issues comes out as statements such as "all amps within their ranges sound the same" and for electrostatics we might find that on the 'possibly correct' side, but *irrelevant*. Because we have to spend a certain amount of money to get an amp where the "within their ranges" produces music loud enough to enjoy.

Shostakovitch's 8th, 3rd movement, for example. I think he is simulating bombs or early WWII rockets coming down during the siege of Stalingrad or some other battle, and for that half second the music might be 95 or 105 db or something, whereas it is 85 before and after. If our requirement is that those parts sound perfect (isn't that why we get expensive stuff - so it is sounds great at the extremes?) So now, the requirement is 105 db stability at 4 ohms. Not easy! That is 85+20 db, so 9*3 is larger than 20, so 1 doubled 9 times is 1->2->4->8->16->23->64->128->256->512. That is a lot of watts! And we are talking real watts, not marketing watts.

I'll try and get a read on the db of the peaks during that piece if I can tonight.

Not sure if I still want to do any tests this weekend, I've resolved in my mind the issue of $50 and $100 dollar amps/receivers compared to Pass equipment.

The issue of a $1k amp vs a $5k amp is another matter that I'm not interesting in starting a discussion on here. That remains open, and his testing methodology might be interesting (in that it adds an EQ and thus suggests that all of what we feel are important differences may in fact be resolved through TACT/Rives type high quality EQ equipment) for that question.

Note that 'tube experts' have failed his test comparing tubes to solid state (let alone Class A to Class B to Class D solid state) because his eq was able to make the SS state amp sound like the tube amp or vice versa, don't know which way he went.

So, in summary, things decided:

1) Personal Claim: His methodology so far seems sound within its own realm - within its stated claims and limitations
2) Fact: Hard to drive speakers require serious amps
3) Fact: Serious amps are generally more expensive
4) Conclusion: It is worth buying expensive amps if you want good sound from hard to drive speakers
5) Conclusion: His 'all amps are the same' testing methodology has nothing to offer us pro *or* con in terms of #2 - 4 above - it doesn't deal with those issues at all

Things still open:

1) Do amps play a part in non-EQ-alterable sound artifacts, like soundstaging for example.
2) If we think they do, then can we ABX our way through identifying them?

Don't discuss those here, however! Lets leave this thread focused on super-cheap amps versus amazing amps used with electrostatics.

Well, that was time well spent, no?

:)