Anyone have an explanation for break(burn)in

[ryuji]

I thought it was my output tubes getting burned in the first time. I pulled apart my amplifier and rebuilt it ground up, and first day with my high end source it sounded great, sent it off to be upgraded and with my low quality source it sounded 'close but not quite' what the old circuit sounded like. Second day it sounded same, now it sounds better, even with the low quality source.

Cant be the iron as that's got a year of use behind its belt. I have changed coupling capacitors and while they did change over time but it was subtle. Also one set of coupling capacitors are salvaged from the previous build so they are already 'broken in'(only thing i salvaged, actually) do resistors etc 'burn in' too?

Dont think it can be psychological, My family member that's only been exposed for a few minutes at a time said the new circuit before i sent my source off to be upgraded was quite the improvement, noticed the next day when he came to say hi that it sounded worse, and today it sounds close enough that we cant tell whats different anymore from now vs first day with good source

[Wavebourn]

I think you should search before opening another one thread on the same theme, then contribute to the one of them you like more.