I recently finished my gaincard inspired amp, it uses a National Semiconductor LM3875 power opamp in the inverting mode. I decided not to use any coupling caps or the Zobel. I used 2200uF/35V Nichicon MUSE caps for the power supply and a 1.0uF film cap as a bypass. I used carbon film resistors that I matched myself. For the power supplies I used 28VCT/4.6A transformers with single bridges using four 60V/5A schottkey diodes.
The chassis is made from 1/2" mahogany, 3/4" pine, 1/8" aluminum plate, and polished aluminum heatsinks. I haven't found a suitable power switch yet so in the Zen fashion there is no power switch: plug it in to turn it on, unplug it to turn it off. Unlike sakuma's amp there's no volume control, I use my Foreplay preamp(the silver box with tubes sticking out).
I also finished building my Dackit (the small black box) that I bought from Scott Nixon, it uses a Crystal CS8412 reciever chip and a Philips TDA1543 16 bit DAC. I used Elna Cerafine caps and Black Gates for the output caps. The power supply is a 12V/8Ah sealed lead acid battery. I am very happly with it!
To learn more about these two projects go to the Audiophile DIY board
To order the Dackit go to Scott Nixon's DacKit Page
