Propeller Head Plaza

Posted by Pat D (A) on May 30, 2007 at 21:45:28

In Reply to: RE: More Testing Of Tubes (Mastersound) Vs Transistors (Jungson) posted by thetubeguy1954 on May 30, 2007 at 06:44:30

It's not my fault the Bored told you not to respond to my posts or even mention my name. That was your problem, not mine. While I have not since then responded directly to many of your posts, I fail to see why I should avoid commenting on various points you raise simply because you were not permitted to reply. I point out that even though I responded 7 hours and 48 minutes later, mine was the first response to your thread.

1) I wanted to know what speakers you are doing because that is certainly a relevant question when considering whether it might be overdriven by a large amp or whether the amp might be clipping.

2) We were both speculating (I made that quite clear) as to the reasons for the differences in the sound of the two amps--which I am taking for granted even though you did uncontrolled sighted auditioning as it is quite likely that a tube and a SS amp will sound different. We were considering possible explanations, and I simply suggested some that I think are more likely than the ones you discussed.

When something happens that one wants to explain, it is often useful to list the things that could have caused it in order of probability from the most to the least possible (this is the speculative part). It is usually better to test the most likely things first to determine which one(s) are real.

3)You have not proved that either amp was clipping. And since you give no indication of level matching when auditioning the two amps, so it is quite possible that you played the speakers louder with the larger amp. You haven't eliminated that possibility that the congestion and harshness was due to playing your monitor speakers too loudly.

Most tube amps do not have a flat frequency response into speakers whose impedance varies considerably with frequency, because most tube amps have a high output impedance (and that usually varies some with frequency, too). So, you have not eliminated differences in FR as accounting for the differences in sound of the two amplifiers, both the bit of harshness and congestion (especially as you evidently did not level match) and the soundstaging.

4) You are to be commended for attempting to test whether frequency response could affect the image and soundstaging. However, the way to EQ two amps to sound the same is to measure the FR at the speaker terminals and EQ them so that they match very closely (within 0.1 dB if possible) in the frequency ranges where hearing is most sensitive and reasonably close outside that. As I explain in a reply to a subsequent post, the 3 dealers you mention evidently didn't do that.

5) In your original post, you said the following: "With the Jungson the backround singers sounded as if they were standing directly behind behind the lead singer, but with the Mastersound you can hear these same singers are actually some 5 or 6 feet behind Steve Moo." You later say you agree that you do not know where the backup singers were actually located.

I made no comment on your "subjective opinion" of what you heard. Indeed, I assume that is how it appeared to you.

6) No comment.

7) Here's the whole sentence from which you snipped a clause: "But indeed, you evidently like some things about the JungSon amp and other things about your Mastersound 845 tube amp, so it's really hard to see how your example proves expectation bias is not at work." Since you had not stated what your overall evaluation of the merits of the two amps was, I am not sure what you would expect me to say. But now, since you have stated you still like the your Mastersound 845 tube amp better, which I suspected, it still reinforces the point I was making: you can hardly use this to show that expectation bias was not at work!

But I also reiterate: expectation bias is only one possible influence. The chief thing is that human beings are built to perceive differences, and will perceive differences even when they don't exist, as jj pointed out.

TG54
"Maybe you're correct and most tubed amps are euphonically colored. I don't happen to agree but even if that's true it wouldn't change my opinion. If indeed the Mastersound is euphonically colored then somehow that translates to the most realistic replication of music I've ever heard ---so far."

Many tube amps do not have a flat FR into many speaker loads. That is simply a fact, nothing defensive about it, easily verifiable by looking at the technical reviews of amplifiers on the Stereophile site, the Soundstage site, and in the old Audio magazine. It is virtually impossible for most consumers to accurately predict just what a tube amp is going to sound like with many speakers. Whether the result is "euphonic" or not depends on the speaker and your taste. Your amp evidently works for you very well.

__
"Opposition brings concord. Out of discord comes the fairest harmony."
------Heraclitus of Ephesis (fl. 504-500 BC), trans. Wheelwright.

Edits: 05/30/07   05/30/07