Originally Posted by RWetmore
I asked this very question to our friend Kurt from Blue Jeans Cable.
Audio cable manufacturers, other than the folks from Belden, are not typically the 'go to' for straight talk on audio difference, much less difference between amps.
Here is his very detailed and informative reply:
Be still my beating heart. Jjust for giggles, in what form did you pose the question to him? Did you ask 'Do amps ever sound different?' or was it a question that WASN'T a strawman?
"Yes, absolutely, it's possible for similarly-spec'd amplifiers to sound
different from one another. This is very different from, say, expecting
cables to sound particularly different from one another; amplifiers are
active circuits; they have circuit impedances that vary with frequency,
filtering circuits which modify signals incoming, outgoing, and in process,
and semiconductors (or tubes) that have different noise floors, gain
characteristics, et cetera.
Let's see some data that those differences are ROUTINELY above audible threshold.
This is a bit like designing a camera lens:
there's no simple, straightforward design that combines the best of all
possible outcomes, and so every design is something of a compromise between
competing objectives. The ideal amplifier is perfectly linear within its
operating frequency range, causes no distortion, cuts off sharply outside
its intended frequency band, and presents all of these characteristics
regardless of the type or level of input signal and the amount of gain
required--but this ideal amplifier is an idea, not a reality, and real-world
devices can and do differ in meaningful, audible ways, even as they attempt
to realize that ideal.
And this is a ******** argument, because amps don't have to be 'perfectly linear' to be audibly indistinguishable, and a difference can be 'meaningful' in objective terms (if, for example, a certain design target is to be met) but be irrelevant in audible terms. What's required is that their linear and nonlinear distortions remain below thresholds of audibility.
Now, it's also probably fair to say that there is a lot of overstatement,
and some misconceptions, that people engage in when DESCRIBING the
differences between amps. Two good amps, both fed the same material and
driving the same speakers, ought to both sound good; but they may sound
different from one another, within a limited range.
Under what conditiosn, pray tell?
Obviously, if they
really sound profoundly different from one another, something is probably
the matter with one or both of them. We run into this in audiophile stuff
from time to time; for example, tube amps will often be said to be "warmer"
than transistor amps. That's true if one takes a certain view of what
"warmer" means; tube amps typically soften the highs a bit and that causes a
presentation which people often describe as warm. But that "warmth" comes,
of course, at the price of accuracy of reproduction of the input signal.
Whether one likes it or not is, of course, another matter.
Gee, that's nice, but no one is arguing about tube vs SS amps
I agree with Kurt as his explanation is the most consistent with my own listening experiences.
Instead of bothering people like 'our friend Kurt', how about reading the E. Brad Meyer article I linked to? It laid out the potential causes of difference in layman's terms quite nicely, some 20 years or so ago.