My original repair (replaced burnt-out capacitor with a higher temperature part) failed agan after 12 months - this time many components burnt out.
So I tried the external power supply
solution discussed here. Well, that was great advice because it worked well.
For your information, I have posted a parts list, LM317 reference curcuit, and photos of my repair here:http://freepdfhosting.com/9333705bcb.pdf
I'm using a 13V plug pack and can't detect any difference in volume or performance running the amplifier at 13V or 15V vs. 18V.
My LM317 circuit is supplying 9.8V to the system unit.
The LM317 casing sits at 90C using an 18V supply
. At 13V it sits at 60C. So for this reason I suggest 13V or 15V supply
is preferred for this configuration.