Some background: OK so for those of you who have seen my thread about the shoddy repairs to the Deluxe I bought today know that I have two deluxe non-reverb amps now. Anyway, my FEI deluxe has the awesome original Jensen speaker, the FMI one I got today has a replacement... an oxford from the early 70's. The FMI has also had some shoddy repairs and is chock full of crappy chinese and bottom-of-the barrel russian tubes... including some incorrect 5881s (should be 6V6). My amp has all Mullard preamp tubes and brand new NOS Marconi/Westinghouse 6V6s which are awesome. The mystery begins here... that deluxe I got today... with a not-so-hot speaker and crappy tubes and shoddy repairs... sounds better than mine, much to my surprise and dismay! I'm trying to figure out why this is... I have a theory which I want some input on, discussed below... All of the circuit board electrolytics on the FMI have been replaced. My FEI has two (or three, depending on how you count the two-in-one on the right) that are still original and way past their life expectancy. See pic... I also tried switching the speakers on the amps... all that did was make the FMI sound even better-er than the FEI. I should also say that my FEI has at some point had the power trans. replaced with a newer Fender replacement (supposedly OK), but according to some other threads this shouldn't make much difference in tone anyhow... or should it...??? Or maybe the Deluxe (or me) just likes the 5881s instead of 6V6s... can anybody give their own opinion one way or the other on this? SOOO (sorry for the long post) my main question is, as someone who's just getting into the technical side of things, what do those electrolytics on the board do? How do they affect the sound when they are failing? When they are new? Any other ideas? I know you all are thinking "just keep the one that sounds good and ditch the other one" but I sort of have an attachment to my amp (I know it sounds dumb) and I want to make it all that it can be. Changed transformer and all, I love it. I have always thought it sounded amazing, until this other one came along!! Thanks in advance guys.