All amplifiers sound alike......... (1 Viewer)

[Angelo.M]

Seems like this is the 10th or 11th iteration of this discussion I've come across since joining HTF last summer.

If it sounds better to you, then it sounds better to you. Beyond that, who cares?

For what it's worth, think speakers. I've heard inexpensive AVR's that sounded sublime with the correct speaker choice, and high-end stuff which sounded lousy because of poorly-matched speakers.

 

[Mark Davenport]

you guys should do a google search on this type of thread. Trust me this was the topic that destroyed Rec.Audio.opinion and this topic started in 1996 and is still going on there.

People have died through the years who were regular posters there and still people in this debate drag their names through the mud. This topic should be off limits on any respectable audio board.

No one ever wins this arguement no one ever changes their mind and it simply ends up resorting into name calling. Please run don't walk away from these tpics if you ever want to enjoy listening to music again in your life

 

[Lee Scoggins]

You scientist geeks think you can say there are no differences based on mere measurements!

Robert, you seem to only post when there are DBT arguments on the board. It is very valid for subjectivists like myself to question whether science can measure all audio phenomena. Even Floyd Toole says that science has not been able to measure all things audio. Plus, we have the very recent and substantial issue with jitter in the early 90s which accounted for sonic difference in CD transports. Also, keep in mind that some audio metrics can occur in one dimension, but not measure concurrent with other dimensions. In other words, simultaneous metrics are just starting to be developed that will shed more light.

No one discounts science' contribution, but to assume it is all knowing and perfect betrays it own history.

 

[Yogi]

Another flame bait

Me sir staying out.

 

[Lee Scoggins]

Such as?

Okay. Here are a few notable concerns about these tests...

First, a lot of these test involve equipment that is not sufficiently resolving. If one is testing only for amplifier differences, the rest of the system should highlight and focus on those differences as much as possible. In many cases, the equipment is never listed. How can we judge that people could hear anything if crappy sources or speakers or both were used?

A second problem has been administration of the test. Many web-based stories do not include what the background of the audience is. Are they critical listeners? do they have a background in recording and know what to listen for for accuracy? How are the statistics kept? Often, the music samples are too brief for assessments to be made. Or the testing is so long that listener fatigue sets in and obscures results.

A third issue has been how the switching was done? Are there aural or visual clues about the switching that keep each listening option separate? Also, in the example of the $10,000 amp challenge previously reported here, the gentlemen doing the test did not put the money into an escrow account administered by a third party. He is clearly being biased by the possibility of losing his money. The statistics may not be kept or shared as well so evaluation of the project's validity seems in question.

A fourth issue is that some test merely put so many conditions on the parameters (impedence, design, etc.), that the circuit topologies are not allowed to be different so by definition it forces a certain result.

Fifth, some tests I have seen don't test with acoustic music samples which many agree is easier to listen to for differences in frequency response and the like. Sometimes fewer instruments and small ensembles is the best for testing a playback system. Chesky and Reference often use single instruments for equipment checks and audio tests.

These are just a handful of the issues one encounters.

I think the best thing one can do is seek a good independent dealer and borrow the amplifier, place it in your own system, and spend a good few days getting to know its sound and whether you like the results.

The human ear and brain are very impressive instruments that far exceed scientific metrics. They are the best judge of sound accuracy and naturalness. Not an oscilloscope or frequency response curve.

 

[Cagri]

given the equipment I currently own, what could possibly occur to make the Kenwood undistinguishable from the Onkyo. Are you suggesting equalization or what? Maybe I'm stupid or not getting it, but all I know is that if I crank both of them up to the listening level I prefer, and on the Onkyo it is somewhere around -30db and on the Kenwood the same apparent level was around -20db, the Onkyo blows the Kenwood away. Yeah, maybe if you add equalization to the Kenwood you could make it closer, but if the Onkyo attains the same level of performance without equalization then it's a better receiver and my ears have told the truth.

Kenwood's specs is 5*100W one channel driven, 1kHz, 0.7% THD @ 6ohms AFAIK. That looks to be the reason of the difference you mention.

 

[Brett DiMichele]

Lee,

You say your Audio Research amp is accurate. And that most
likely is true becuase from my own research into higher end
tube gear they are fairly accurate and some are definatly
broadband on thier FR. But that doesn't mean it's not a
euphonic device. It's still adding a different kind of
distorsion to the music than a straight solid state device
would, not to mention that tubes can also be microphonic in
nature and even if you have the chasis dampened will the
tubes can still pick up some vibration and pass it back
through the signal.

I just spent all day yesterday listening to my $500.00 ASL
Tubes and I smiled all day.. It was fantastic..

I am glad I am so cheap and easily amused Leaved more
money for me to spend on my sports cars. LOL

 

[RobWil]

"Kenwood's specs is 5*100W one channel driven, 1kHz, 0.7% THD @ 6ohms AFAIK. That looks to be the reason of the difference you mention."

You're thinking of the 605 I think. The 6050 is 5x100, both channels driven into 8ohms, 20Hz-20000kHz and @ .09% THD.
I agree...if that was the case that would explain it.

"Seems like this is the 10th or 11th iteration of this discussion I've come across since joining HTF last summer."

"you guys should do a google search on this type of thread. Trust me this was the topic that destroyed Rec.Audio.opinion and this topic started in 1996 and is still going on there."

Sorry!.....leave it to a new guy to screw things up
Yeah, I know...it's the same no matter what forums you go to. I've spent alot of time at edmunds.com discussing cars and you get it there to. It does get old but the only problem is that if these subjects didn't come back around you would eventually run out of new things to discuss. You have to admit though that you can scan the topics here daily and not find anything worth participating in for several days or longer. The last thing I want to do is start a war. I didn't realize this was such a touchy subject.
Now having said that, no one is being forced to participate, for sure.

I can kind of see what the author is thinking. An amp's only job is to amplify a signal and pass it on to a speaker. And supposedly distortion levels of .09 or less are inaudible. So if their only job is to amplify the signal, and not to process the signal in any way, then how could there be a difference in the resulting sound?
But is the amplitude of the signal necessarily provided equally across the entire frequency range from amp to amp,cause what I think Chu was trying to tell me is that if you equalize the kenwood it would be comparable.

 

[Scott_N]

I heard a big difference between a Cary V12i and a Quad II-forty on the same speaker with the same music this weekend and I liked the Quad better even though I thought the Cary was what I wanted. I can hear sound changes with different tubes in the same amp. I let "my" ears not some lab report tell me what sounds good.

 

[RobertR]

Often, the music samples are too brief for assessments to be made. Or the testing is so long that listener fatigue sets in and obscures results.

So if the listening time isn't EXACTLY right, neither too short nor too long, the test is invalid? Funny how no such restrictions are needed during OPEN comparisons. The claim is also contradicted by the often heard claim that one needs WEEKS or MONTHS to hear differences.

 

[RobWil]

"It's rather embarassing when people can't hear differences with Krell, Wilson, and Pass gear."

Well that's nice to dispute but the article in question was not talking about comparing higher end systems. He claimed no one could tell a difference in the $200 cheapo receiver and the $12000 pair of monoblocks.
What you're saying is entirely believable.

 

[Lee Scoggins]

I can hear sound changes with different tubes in the same amp.

You can also hear important changes when you put ARC tube rings (polymer bands) on your vacuum tubes. They damp microphonics. The more experience in audio you have, the more you know how to improve the sound.

 

[Phil Iturralde]

Phil

 

[Mark Davenport]

Here's the bottom line, buy what you want, figure out what you want to buy how you want, and enjoy your system.
Until people can realize this these types of threads will keep popping up.

Everyone in this thread should just do searches on other threads like this. They all start off the same way, it's like a pattern, and everytime nearing the end of these threads is name calling, people yelling and screaming at each other to "prove" each others claims, one side putting down the articles that one side thinks prove there claims.
The pattern gets followed to a "T" every freakin time. But people still insist to argue about this they still insist that this time there opinion will win out and they will have proven to the other side the 100% Absolute truth of there claims and opinions.

Come one guys you should have better sense than to fall into the trap that is this subject. It's simply objective VS subjective in disguise and you never gain anything from it.

 

[RobertR]

In many cases

What does that have to do with the cases where it's true? It never ceases to amaze me how condition after condition is met for the subjectivist, yet he always comes up with "something" wrong (the phase of the moon, bad biorhythms, wrong record label, etc. etc. etc.).

 

[Jonathan M]

The human ear and brain are very impressive instruments that far exceed scientific metrics. They are the best judge of sound accuracy and naturalness. Not an oscilloscope or frequency response curve.

Lee - Please tell me:

What differences could there possibly be between two amplifiers that are not picked up by the null testing method I outlined in my last post??

I'm sure you understand that in order for a speaker to produce sound, it must have a current driving through it's voice coil. This requires a voltage to be present across the speaker terminals (As the coil is an impedance) and thus the movement of the speaker cone is a direct result of the voltage across the speaker terminals. If we don't measure any voltage difference from 2 different amps driving the same speakers, then surely they MUST be producing the same thing?? If the difference is in the order of 60dB below the signal level, (As it often is with two well designed amps) then this will be extremely difficult, if not impossible, to discern when one considers the noise floor of most listening rooms combined with the distortions introduced by the speakers and the listening environment.

 

[Chu Gai]

Without further clarification, which can get tedious I know, it's difficult to comment upon your post Sam. I can only restate what's been said before. If the differences were indeed as dramatic as you say, then a level matched, side by side, unsighted listening session would bear what you said out.

Well for starter RobWil, the simple fact that you haven't correctly adjusted the output levels. You can always download and burn a test tone...1 kHz sine wave and use a multimeter to adjust the levels at the speakers. Then you've got to come up with a way to switch one receiver in and out without your knowing which is which. BTW, the weakest link is you the listener. It is a well known tendency in humans, which probably excuses those of golden ear and various members of the audio press, that not only will we overestimate or exaggerate differences when in fact the differences are small, but we will also report differences when there are none. Rob, in the latter case, you can prove that for yourself quite easily. Simply use a set of 12 gauge speaker wires and pick up a set of some high priced cable. Have some friends over to tell them you want them to check out this new wire. Listen to whatever. Fake the cable switching. Have them listen again. Like I said, if you want to pursue this at your home since you've got two receivers you can do this. I'd be pleased to suggest and comment either via PM or on open forum. At the very least, you'd come to understand a bit the attention that needs to be paid that led to the article you originally posted. You're a technical sort of person...let's get technical.

Lee, we're all free to spend as little or as much on whatever it is and to also think or believe anything. However to get to the truth, the inner kernel then you've got to eliminate biases. We could certainly take your Golden whatever cables and determine at what point audible differences occur as we decrease the gauge of another wire. Maybe somewhere around 38-32 gauge depending upon the speaker and cable lengths I'd imagine. Perhaps thou needest to personally experience this yourself. Sometimes I think that if you were a mustard afficianado, that you'd find equally personally compelling arguments against taste testing too. You don't have to treat or react to a blind test the way a vampireacts to garlic...it is garlic isn't it? You'd think a southern boy, in the heart of NASCAR country, would be chomping at the bit to duke it out, head to head, side to side.

For those who are interested, below is a partial list of references that you may wish to pick up. Likely your local library can obtain them on inter-library loan.

"Effects of Cable, Loudspeaker, and Amplifier Interactions", F. E. Davis, J. Audio Eng. Soc., June 1991.
"Signals & Noise", R. Allison, Audio, January 1994.
"Examination of Audio-Bandwidth Requirements for Optimum Sound Signal Transmission", T. Muraoka et al., J. Audio Eng. Soc., Jan/Feb 1981
"An Introduction to the Psychology of Hearing", B. C. J. Moore, Academic Press, 1989 (3rd ed.).
"The Filters in our Ears", F. A. Everest, Audio, September 1986.
"Audio Engineering and Psychoacoustics: Matching Signals to the Final Receiver, the Human Auditory System", E. Zwicker and U. T. Zwicker, J. Audio Eng. Soc., March 1991.
Greiner, R.A., "Amplifier-Loudspeaker Interfacing," JAES, Vol.28 No. 5 (May 1980).
Johnson, J.H., "Power Amplifiers & the Loudspeaker Load," Audio, August 1977.

Perhaps you can point to similar publications, texts, and peer-reviewed journals Lee. Modern Cold Fusion doesn't count though

 

[Lee Scoggins]

FYI: June 1998 Stereo Review - "To tweak, or not to tweak?" (Blind-Test: $6,400 Tweak system vs $1,700 Geek system) by Tom Nousaine ...

Phil, give us the rest of the story - what was the playback system, the listening audience, the test method, the observed data, etc. This partial excerpt tells me nothing.

Also, you do realize Stereo Review has always been from the "objectivist" camp and rapidly lost its readership and the audiophile community as a result?

 

[Lee Scoggins]

Perhaps you can point to similar publications, texts, and peer-reviewed journals Lee. Modern Cold Fusion doesn't count though

Chu, Listing a wide variety of audio literature does not tell us anything about DBTs. There has been no paper from the AES that has proven that perception problems overwhelm sonic differences.

 

[Mark Davenport]

Oh well, I warned you guys, I'll stop back next week once the name calling really picks up. Trust me no one can interject anything usefull in this thread it's all been said and done a million times before. Stop now before it's to late. Have fun.