Building for use with battery.
The good news: Built the amp and have music playing through it. I'm at 24v using a variable power supply with variable current limit set at 180mA.
The bad news: Slowly turned up the supply voltage. At 42v the amp died. Current limit pegged and volts went to near zero. Raised current limit but to no avail. Troubleshooted it for a while and found the problem goes away with the removal of the sta517b chip. Installed another and adjust the output offset voltages and the amp plays music again. Raise voltage and again the power stage chip gives up the ghost same as before. I remove it and the amp4 resumes normal current draw. But...I'm out of chips unless I put a 2050 in there. Both sta517b chips have numbers 991D3 937 on them.
Did I get bad chips or am I a bad chip installer? Modulator fb total resistance is 24.9k. Input gain is -2.5. Vpp sense resistors are 357k. Bulk caps not installed. C102,c103 not installed because I bought 63v 1500uF and they are too big. I couldn't wait to test amp so I proceeded without them. I do however have some 63v 470uF caps on order with proper lead spacing. (live and learn)