cap choices
Most of the ones I mentioned are on ebay commonly. The green PIO russians are around a lot. I bought a dozen of the lesser known Tauras polypros from a guy in England off ebay. Never heard of them either and wanted to try them. Very cheap in price, pretty good sonics.
BG's some like for coupling, I believe there are better choices. But most of the choices I like won't fit on the board so you need to put these off board. I put the input coupling caps directly on the input RCA's and then wire the output onto the Amp3 board at the normal input. Just jumper over the caps on the board so the signal gets into the SMD resistor and onto the tripath's input.
The large black cap is part of my capacitor board in the power supply. Jan mentions using up to 20,000uF capacitance for a 12V SLA battery supply. I just put a bunch of Nichicon Muse KZ's in parallel as well as the big black one (a larger value Solen), these are all between the +12V input and ground. I used both polypros and electrolytics on the cap board to try and get the benefits from both types of caps.
If you wanted a good quality input coupling caps, I'd go either plastic/polypro type or paper in oil. Getting a large enough PIO is not as easy as finding a larger plastic caps. Use Audience, Relcaps, Kimber, Cardas, Sonic....all these are commonly available and nice caps. What you need to realize is many of the best couplers are rated much higher than 50V and but can still be used in your amp.
If you want a path of least resistance, get the audience and try that. Most love it's sound and it's price is reasonble....but good poly's are still at least 5 to 15 dollars a piece. Some much more.
Have fun with it. Ebay is a good source of many exotic caps...especially if you don't mind dealing with the Ukrainian guys.
