Observations of amplifier sound

[bigwill]

This is how I've perceived the following types of amplifiers, I'm wondering if anyone hears the same thing as me...


High FB Class-AB solid state amplifiers:

Sound fine at first, you wonder why you bother with valve amps. Things sound as they should, nothing sounds distorted. Then you hit some sibilance from a singer or loud cymbals and your ears burn off.

Sibilance sounds like harsh, bright white noise. Things with less extreme white noise content such as a singers breathing have a strange "edge"

Treble extension seems to be good

Bass is tight but slightly lean depending on the speaker, obviously due to the high damping

High FB tube amps:

Sound good, but try to minimize clipping. Sibilance is much less unpleasant than the SS amp. Sibilance is rendered nowhere near as harshly, but it still seems to briefly drown everything else out with a darker "ssss". The amp is still enjoyable to listen to.

Bass good but not quite as damped as with the SS amp, but is pleasing.



No FB tube amps:

Treble actually sounds rolled off at first, but this is easy to adjust to. It's just different. Things like reverb and echo suddenly become apparent in recordings you've heard hundreds of times, it's somewhat unnerving, you can actually hear further "down"

Sibilance is much improved, doesn't seem to send the amp into a strange "overload" condition (I know it's not literally like any kind of overload but it's the best I can articulate it)

Bass will be less damped but this can be overcome with speakers with this in mind

[Michael Koster]

--- Things like reverb and echo suddenly become apparent in recordings you've heard hundreds of times, it's somewhat unnerving, you can actually hear further "down" ---

This is the main reason I'm switching to a tube amp + high eff speaker
system for my recording studio monitor system. It's sometimes called
"resolving power" as if it's some kind of microscope, which it does
seem to be relative to my current SS Haflers and 86db speakers.

I'm convinced that this can be measured as follows, with music as
a test signal, using some subtractive techniques. Take 2 identical
amps and combine the outputs in opposite polarity. Null these using
sine waves and a notch filter. Music program should also null out.

Now do the same with 2 different amps you want to compare. On the
music signal, any differences in response will appear at the "A minus B"
output.

Cheers,

Michael

[inertial]

I like your "observations" bigwill, very intersting!

I tend to agree at all. This is the reason because I think multiamp
can be the "solution"
Very radical but it works IMO

Cheers,
Paolo

[rdf]

Don't disagree with the general observations but it's still odd considering that, in light of the rising high frequency impedance of most speakers, NoFB tube amps should sound brightest due to the high Zout.

[analog_sa]

These observations are really stereotypes and simplifications. If all three amps are built to an equally poor standard and very limited music samples are used i would agree with the conclusions.

Sibilance and harshness with NFB SS amps? The good ones have been free of these afflictions for many years. As far as ambience, microdynamics, image palpability and tone go, yes, NFB free tube amps really rule. But it's not all peaches and cream. How many of that breed can take a full orchestra and not fall apart in the crescendos?

[inertial]

analog_sa ,

please can you post some "names" ( commercial brands) of overall feedback solid state amps that ,in your experience, sound extremelly good ?

Cheers ,
Paolo