I have finally built this kit after it sat for a while, and it’s having problems. I’m using a bi-voltage supply: 12-0-12 AC. When I switch on the circuit it gets loaded down to +/- 8 volts. On the negative side there is also 3.8 volts p-p of ripple (no appreciable ripple on positive side). Even with no input signal, the heatsink gets quite hot. When a sine-wave is injected, it is highly distorted.
I’m guessing that one of the PS filter caps is not working right? Would that affect the amplifier IC (the ripple voltage) and cause the heating? Any thoughts are appreciated.
Thanks and best regards.