Was playing guitar thru amp, sounded great, then went low volume...opened amp, cked power supply voltage +40 -40at filter caps... good, transister Q9 getting hot. Both Q8 andQ9 ck good out of circuit. Found open c8 replaced both c7 and c8 with electrolytics 33uf @ 50v. negative voltage dropped down to 34v while positve stayed at about 39v. Q9 still getting warm?? Any suggestions appreciated....