Today I made tests to the power stage always with a 70 watt incandescent lamp in each feed rail, by injecting a sine wave of 1 kHz and load fantsma the amplify the wave came out clean, good achievement but the bias of the left channel was nails in 230mV are about 35mA but I can not lower the preset has no more travel and if I give it to the other side goes up, the other channel with bias well preset to the minimum with 40mV. It can adjust to 35mA.
Now that you can power it on with out a bright bulb try taking that out and power it on to full voltage. Let it rest for 20 minutes then check bias and set at .350 mv and check positive to negotive output binding posts for dc offset hopefully you will have 10mv or less.
I put 1.5 or 2 amp fuses in the output fuse holders for this trial. Remember to change them out wince you are ready to pull something more than 1-2 watts of output.