Tube Amp, Preamp upgrades -- what did you do that improved your units?

Thanks and I'm glad to see some agreement about the non-oil Mundorf SG's.
It's confusing enough to choose between brands, let alone there being such differences within a brand.
And, as opposed to tubes, once these pups are soldered in it will be a harder call to reverse them.

Don't know if you're aware, but Humble homemade has reviews on most top line caps, will give you some idea of sound qualities.
I don't think you can go wrong with any of the top rated copper films, the Mundorf Evo might work if you didn't go with silver internal wiring. I'm just thinking you're looking for spaciousness, more extension on top, reason for silver. You also may not need any silver, that's up to you.

Just came across post from Aric of Aric Audio. States he prefers the Miflex to ODAM in his amps and pre's. Just goes to show you're going to find all sorts of preferences in caps and most other boutique parts.

I like the Miflex, Audyn True Copper Max, VH Audio cutf, Mundorf Evo, Jupiter copper film, Duelund copper, these all among the best, again, sure odam right up there. Personally, I wouldn't sweat it, get any of these, your amp and pre will be so much better.

@sns  Thanks! It's like speakers -- many good ones out there, can only try so many!

I am looking especially among QS folks, with some eye to what they like in an amp. That said, they'll have different rooms, different speakers, etc. It's a crapshoot. But a better quality part will, whatever its character, offer more of some basics, whichever particular subset they happen to be.

That is funny. I dislike Miflex. Far too forward sounding to me. I replaced them in my integrated amp and past tube dac with Odams. The Odams were clearly better in every sonic parameter.  Now Vcaps do take awhile to burn in. Longer than Miflex. Wonder if he did not give them 150-200 hours! If not, that is why. The Odams can sound constipated and bass shy initially. 

I know the Miflex very well. Just can’t get past how pushed forward the stage is. I know two other builders who now offer Odams over Miflex based on listening tests.  
Go figure.