bud chassis

[Abstract]

Most likely the caps and tubes mellow with burn in.

Can you quantify what occurs with "mellow"?

I think most agree something happens, whether you want to call it "mellowing", "warming", "softening", or "sweetening"...

...should this be attributed to component drift or some other active component variation?

If drift, is it an increase in spec or decrease? Is this determined by component material? Is this random or could it be planned for? If random, why would the same observances happen in wildly different designs and topologies? If this "drift" isn't random, can designs be implemented that take advantage of this "sweetening" from birth?

I've noticed this and often wondered these same things.

I don't think tubes have much to do with it because they get changed and the "new sound" doesn't come back.

[CaseyJones]

Electrolytics no matter how well they're formed to begin with tend to re-form every time you play the amp... up to a point. Try it, pull 'em outta the poly bag, test 'em, solder 'em into the amp, play it some. Take 'em out and re-test 'em. And I don't mean on some BS handheld meter with 9 volts applied, you' just foolin' yourself with that setup.

Film 'n' foil caps to tend to play in. Leave the amp in a closet for a year or so, dig it out, play it some more. They play out in storage! Seriously, I have a couple old Marshalls wif Mustards and they don't sound as good if they're left alone and not played. The more often ya beat 'em the better they sound. I don't mean the caps are crap, I can take 'em out, test 'em and they test o.k.. They just sound better when they're used often.

[Abstract]

If you take a bag of components (of exceptionally close value) and played each in the amp mentioned above, at similar levels for similar times, would each of the component's reform in the same manner?

If yes, to what may this be attributed?