Power supply or audio path? Take a look at my CF amp mod thread. Lots of good ideas from alot of folks.
I'm to fucking lazy, please tell me what I need.
Brian, that's the funniest thing I've heard today.
'I' think the most bang for your buck is to change the .1uf caps. Each amp requires 4 of them.
George rolled in some Auri's and Russian Teflons, I used Obbligattos. Last time I spoke to George he mentioned preferring the Auricaps. You've used Deulands in the Silver 7s, if you liked them, give the Alexanders a try.
Mike Beam modded my power supply to lower the voltage into the range allowing use of the EL84/6BQ5s. The El84s are more reasonably priced. Beemers has a set of Telefunken 7189s in his CF amp. I listened to it quite a bit my last trip out to VHoP and they sound great. Still a lot of $$ in the Teles.
Link to the CF amp nod thread:
The mods I made were a bit more involved. I installed Mills resistors in the audio path, upgraded all of the power supply caps, DH labs silver over copper wire on the input side and the same running between the power tubes and output transformers and from output trannies to speaker terminals. All of the power tubes are Hammond EL84s, driver tubes are vintage 6ax7s. I rolled some Telefunken EL84s, motherfuckers sound great although not enough better than the Hammonds to make me want to spend the dosh to acquire 2 complete sets. I'll give up the slightest bit of bloom of the Teles to get the soundstaging of the Hammonds.
Al has a set of TAD EL84 and IIRC, he likes them.
If you read the CF mod thread you'll notice I tried to describe the incremental changes I heard while making the modifications, which I hoped might make it easier for those following me to decide what mods would make the most sense for them to do based on what they like to hear. I used my Lightstar Reference 2.0 as benchmark to evaluate my progress. The Cf amp faired well....until the volume went WAAY up. There's no substitute for cubic horsepower. And after some coaxing the bass fleshed out nicely.
Point is: roll in a .1uf 630volt (or greater voltage) cap. I would not increase the farad value of the cap. My very limited understanding is the amplifier can become unstable. Decreasing the value limits bass response...or so I'm told.
Mark will be around in a minute to comment and let you know if there are any other considerations you might want to think about or if I left anything out. Oh yeah, make certain all of the caps have discharged. I could taste my fillings for a week. There's 508 volts coming off that 390uf power supply cap. Tasty!!