General:
Generously build big power amplifier
MK 1 ^
MK 2 ^
Special futures:
Later generation integrated amplifier with big power capabilities
User Manual:
Click here to download the user manual in PDF format
Schematic:
Click here to download the service manual version 1 in PDF format
Click here to download the service manual version 2 in PDF format
Modifications:
An update for a first-generation AU-D11:
The stabilized power supply for the preamplifier and power stage driver not only
suffers from 13 Volt zener diodes that 'collapse', but the stabilization transistors
of the + and - 69 Volt driver power supply get very hot and the dried out solder
welds that lead to all kinds of problems over time. I solved that by putting those
four transistors (new 2SB861 / 2SD1138) in a row on a black sprayed strip of aluminum.
Insulate well of course, with nylon bushings and mica plates, because the collectors
have + or - 80 Volt on! Works perfectly, the aluminum plate is now at most lukewarm.
