Are audio companies all involved in a huge conspiracy? - Page 80

That's a problem with the all-amps-are-the-same position. It appears to be empirically empty, since proponents provide an excuse for all potential counterexamples: Amps that test out to be different must be improperly constructed -- else they would conform to the theory.

There is a parallel with another widely accepted theory: The survival-of-the-fittest principle explains how organisms evolve. But "fittest" in this context appears to mean only that progeny are most likely to survive, so this "theory" means no more than that those organisms most likely to produce surviving offspring will tend to have surviving offspring. Duh.

The real problem with "the all-amps-are-the-same position" is that it exists only within the very confused minds of some very ignorant audiophiles (and their very dishonest enablers in the audio industry).
Brilliant. You've just demonstrated that if you oversimplify a theory, it becomes oversimplified. Give that man a Nobel.
I see your grasp of evolution is about as strong as your grasp of audio.

That's interesting, and it would mean tube amps are basically a rip-off. This type of information if true, could of killed off tube amp designs. I mean if I could mimic the "glorious" sound of an expensive SET amp with a Yamaha AVR. How about an adjustable filter box that replicates different tube amps? Or I guess each speaker design would nead different filter types?

Well, it seems that some like a very expensive built in fixed EQ that is anything but accurate to the input siganl.
But, there are much less expensive EQ on the market to get the same results.

This assumes that what tube lovers want is "the sound of tubes." It's probably more the case that what they really want is the tubes themselves. The actual sound is secondary.

Glowing tubes look cool in the dark! But are you saying experienced audiophiles who chose tube amps don't care about what the hear?

For your edification: Is survival of the fittest a tautology?

It is a preference as are vinyls are.
I am sure this is not hard to do with today's microprocessors but the market would be small and not too profitable for makers, I am sure. Besides, some audiophiles would still snub it that the tubes themselves are better.
Why not try a 1 Ohms resistor in the speaker path and see what happens, or a 2 Ohm resistor. A very cheap experiment.

Not exactly. They may care about what they hear, but their actual choices may not be made based on what they hear. And this is not limited to tube fans, of course.

Human hearing, as we know, is very suggestible. So when people express a sonic preference (for anything, really), we can't know for sure whether that preference is based on the sound itself or what their suggestible brain is telling them about the sound.

We can test these expressed preferences, of course, using DBTs of various kinds. If they can't really tell the difference between one amp and another, or if their preference blind differs from their preference sighted, we can infer that there is something other than sound influencing that expressed preference.

Yeah, that's right except EQ doesn't use distortion to attenuate.

Until amps are 100% efficient, basically no bigger than the required wire terminals, generate zero heat, generate no emissions of any sort (radio frequencies, etc.), perfectly reject all interference, and are perfectly safe in addition to demonstrating the sonic transparency that modern solid state and chip-amps do, amplification technology won't be "perfect."

Today, they are merely "close enough to perfect" along one variable: sound quality. They differ in energy efficiency, size, heat output, safety certifications, etc.

It's noteworthy that in blind preference tests of speakers and headphones, people generally prefer smoothly declining sound power with frequency. In sighted tests, they often latch onto something that looks really neat even if its actual performance is lacking.

I suspect the same would happen in a blind preference test between a good amp and a crappy one with high output impedance like the aforementioned Jadis. But in a sighted test, lots of people are conditioned to think exposed glowing tubes = better sound. Even some people who generally aren't retro-fetishists.


That is the truth behind the "Carver challenge." Carver really earned his "Sideshow Bob" nickname there. Masterful acting performance.


Just add resistors to the speaker output taps. That's what the "tube sound" taps on Sunfire amps do. And high output impedance is why the Jadis performs so wretchedly into Stereophile's simulated speaker load.

But it won't kill off overpriced lightbulbs, because people like to look at them. In truth, I do too. There's something about obsolete-looking technology that's kind of cool. But instead of wasting them in my audio system, I buy them at CB2 for $10 a pop and use them solely for illumination...

Kemper profiling amps. http://kemper-amps.com/page/render/lang/en/p/184/do/Kemper_Profiling_Amplifier___KPA___Guitar_Amplification_Redefined.html

Only $2K per channel! Of course it's intended to profile the various departures from flat, uncompressed and undistorted in tube guitar amps. They come with pre loaded profiles, and you can profile Duane's Marshall Model 1986 (a 50 watt bass amp) (if you can get your nhands on it) getting (supposedly) the exact response that amp gets. Of course then you're left wondering why you don't sound like Live at the Fillmore East when you plug in your Les Paul. (Hint: It's in the hands, dude).

I've never heard one in the flesh, or more to the point played through one, and have no idea how well ist does what it does. Let alone whether its testing/profiling system is appropriate for copying any particular Jadis or Conrad Johnson or even a rolloed off 80s Arcam solid state amp. Might not be enough THD for it to even see. I've read that guitarists hear 10% THD as "clean"

I can put "if" in front of anything but how much of it is based on real life cases? I know of a case where a transistor amp was able to mimic a push-pull tube amp sound with the aid of equalizer. Do you know of a case of push-pull transistor amp replicating SET tube amp sound with the use of equalizer?

So much attention to freq response but none as to the actual sound quality between these FR extremes.

What's missing in these discussions is the sound quality, or what the amp actually sounds like on a real life system, within the envelope of their individual flat response.

I'm not defending the FR of the Jadis amp used an an example, not my cup of tea. However, I've heard OTL amps which I'm sure can't do 20 Hz well without higher distortion (depending on the load), yet have an amazing level of clarity to the source at higher freqs, particularly through the ears most sensitive midrange region. They may make a triangle sound like a cow bell, so no they aren't sonically perfectly accurate, but they offer a much clearer picture in areas of the audible spectrum that most solid state designs just can't touch.

Which music did you use when doing this comparison? Artist, album name, track number?

Right, because DBT's to establish what is and isn't audible has nothing to do with actual sound quality.
Such as matching FR of two amps so that this doesn't bias a DBT of their actual sound quality? As has been done and was mentioned just a few posts ago? Again,
Could you describe the unbiased manner in which you reached this conclusion? Was it by comparing measurements, the non frequency response type of course, such as distortion spectrum, clipping behavior, etc? Or did you achieve a zen-like state of purposeful clarity such that all biases were washed away, allowing your ears to function without the interference of your pesky brain??

That's just ridicolous, there you go to extreme measures to avoid having a result. I'm starting to think that version of abx test is designed to test people rather than amps.

Why is that ridiculous? The objectivist argument has never been that ALL amplifiers sound the same (though it may sometimes be casually simplified as such).

The argument is that differences can be measured, that we can measure everything we can hear and then some, and if two amplifiers measure within the limits of what we (think we) know to be inaudible, they will in fact be indistinguishable sonically.

Since the vast majority of amplifiers sold today aim for, and achieve, performance that falls well within those audibility limits, this isn't an esoteric, academic endeavor. The vast majority of amplifiers on the market should sound alike. Controlled tests supporting that make shopping for one much easier to approach.

But back to the ridiculous part. If by means of a few dollars of passive components, we can make a cheap prosound amp sound like a megabuck tube amp or Krell or whatever, then we know there isn't some magical mysterious unmeasurable quality responsible for any actual audible difference. Armed with this knowledge, shopping is again simplified... if you like a non-transparent sound, measurements will guide you there much more efficiently than some random magazine and forum combination of prose.

There's also the implicit argument, often stated explicitly as Joe did above, that certain amps do something that 'solid state/other/whatever amps just can't do.' Well, if you can emulate the sound with a cheap alternative, it exposes that claim as more mere illusion.

As for the second part of your argument, controlled testing actually goes to extreme measures to increase the chances of having a positive result as much as possible. Research has shown that we are typically much more sensitive to rapid changes separated by no delay. Research has been performed to determine our likely most sensitive range of auditory memory. Extensive measures can and hopefully are taken to optimize the listening environment... quite, properly treated space, quality equipment (speakers, mostly)... music is chosen to highlight differences, not mask them. And if that doesn't work, protocols can be adjusted to let people listen at their leisure with their equipment and their choice of music in their home, even if that doesn't optimize their hearing sensitivity but does "make them relaxed."

But if you mean taking away people's ability to "see" what they are listening to as an extreme measure that likely prohibits a positive result being achieved... sure. I agree completely.

No, most amps can be statistically proven to colour, that's not correct. If your tests don't show that, they are not of enough high resolution.

What's the use of mimicking something that's potentially bad? This test does not say anything about which amp that's devoid of colorations, you only prove you can turns something ele into indistinguishably bad.

No, almost all amps can be shown to have no audible color. If your evaluations show otherwise, it is probable that outside biases are creeping in.


In fact it takes no changes at all to make pro sound amps sound like the highest resolution and most transparent high end amplifier. To make a pro sound amp sound like a tube amp is a crime against technology. It is easy enough, usually it can be accomplished by putting a cheap 1 ohm 10 watt wirewound resistor in series with the speaker wire. There is a reason why 99.99% of everybody scrapped their tubed amps, they were simply more trouble than they were worth.

There is absolutely no reliable evidence to support the above.

Extreme measures are not required.

This is the one part that can make a good SS amp sound like a tubed amp:

http://www.radioshack.com/product/index.jsp?productId=2062290

"1.0 ohm 10W 10% Wirewound Resistor (2-Pack) Model: 271-131"



Just put one in series with each speaker wire that is attached to a stereo amp.

It will turn a good SS amp with flat response into this:



(upper wavy line)

No, it's because too few use the signal before the amp as reference in the test, as you well know.

Hundreds of amps has been tested this way - one has not "yet" been detected to color.

Not sure exactly what you object to arny. If I find I like a certain tube amp, and thereafter see its frequency response is horrid and found to be associated with a certain output impedance, I could search out other similarly designed amps with similar output designs if for some reason I needed a replacement or whatever. Surely that is more efficient than reading ragazine reviews describing some chocolate frosty character with a zing zang aftertaste and looking for reviews and forum posts using similar language to describe another amp. ??

If you're saying I need evidence of the above then I cede the point... it isn't something I would think needs to be and certainly never will be tested empirically. If you just disagree that's fine too.

Still not sure your point. If by "color" you mean introduce measurable differences, sure. If by "color" you mean introduce audible differences, you're going to need to show your proof.

I've read that class A type amps can have an audible advantage over push pull types. I dont know the technical explanation but the idea of not splitting the signal can be a better approach, but less efficient and expensive to build properly.

I also read that Class A can capture the subtle dynamIc swings of the recording better, I think the dynamic ability of an amp is very important. Some use over built power supplies that supposedly helps with transient response and dynamics, or is that hores hockey too?

Audible, blind, statistically proven. Statistics showed in magazine article.

Denon PMA-720AE and NAD C375BEE tested in last number of "Musik & Ljudteknik"' which is #4 2012. The magazine has been doing this for years and years...

There's no need for a DBT when differences exists as large as the one I stated above. And again I'm not talking FR differences. It's silly to ignore an entire sector of amplifiers people enjoy day in day out because they do not meet your on-paper ideals, but hey if that's the title of your paper, then it makes sense.

I did trade shows with a small loudspeaker company for years who owned a set of very nicely made 100 watt OTL mono amps (Joule Electra) every show, so I have hundreds of hours of listening to these playing all sorts of material. I'd say that makes my actual experience with these amps hundreds of hours more than your own.. If you spend this amount of time with anything bias tends to drop out of the equation. They sound as I stated as they would to anyone who listens to them.
Edited by Joe Skubinski - 3/16/13 at 7:46am

If you're talking about the triangle sounding like a cow bell, Jack Johnson Brushfire Fairytales, track 3, 'Posters'.

Like the researcher in the Mcgurk clip in this thread who spent years studying the effect, yet is still unable to "not" experience the effect? Right. Your claim doesn't surprise me though. People who make superhuman claims tend to make other superhuman claims too.


Free of bias, right? Wait, can you teleport your superhuman gift to them? Right again.

There are no superhuman claims being made Bigus and you know it. There is no effect at play here either. It's just the way the amp sounds.

There's a trade show in NYC next month, http://www.chestergroup.org/newyorkaudioshow , why not get out in the real world and have a listen for a change. Might improve your balance.