[Heathkit] sb200

[ted]

Still cant get full output from amp.Plate voltage near 2400.Have   -123 volts at grid.I replaced the 20uf and 2uf ,both rated 150 volts. Output abt 375watts.I noticed tubes can get red if keying a little prolong.Only thing I havent done is install 2 new tubes.Tried used spares. I just feel something else is wrong.When I key amp grid voltage drops to say -54 volts.If anyone can help with some idea ,greatly appreciated.Ted