Hi Larry,
Be careful when you start playing with magic parts in your Ultra DAC.
First make sure you can actually find new capacitors of the appropriate capacitance and voltage ratings sized that will even come close to fitting on the analog filter PC board.
The output coupling capacitors are 5.6µF 250V mylar. The capacitors in the gain set feedback loop are 4.7µF 250V mylar, input capacitor is 1µF 63V mylar, interstage coupling cap a 0.01µF 250V mylar. The capacitors in the filter circuit are a 3300pF 630V polyproplyne, a 20 pF 300V mica and a .33µF 63V mylar. . There is also a 2.2µF 250V mylar cap in the connection cirucit between the tube output and mos-fet input, but this one may be hidden on the bottom of the PC card.
I would not expect that just cherry picking and changing just one or two of these would make much difference. Actually I doubt if our original capacitor choices are sonic issues at all.
If you do not match part values channel to channel with a capacitance meter and select parts within a percent or two of what is there now you certainly will hear a difference, and it won't be for the better.
Please don't mess with the digital board.
Have fun playing with it. If you break it we can probably still fix it.
Regards,
Frank Van Alstine
