hello ! i am new at this site ! i need help with an rca tube amp. the amp i have is a three channel amplifier running on the 6bq5 in p.p. , the 3rd. channel is supposed to be for the base . both left and right channels work and sound great , but the base channel i cannot figure out how to make it work properly , when i power it up after a minute or so the woofer oscillates and goes in out like crazy but no sound can be heard , this happens even when no signal is applied .
i changed coupling capacitors , power suply electrolytics caps , all resistors , i even installed new tube sockets , also tried with another output transformer , removed all components and re installed fresh new ones and still i get severe oscilation on the base speaker , with or without a signal .
can anybody out there help !
