Tube Amp Archive

Taking your advice, Martin, I checked the biasing of the transistor. Here's a snapshot of the oscillator circuit: [img:473:361]http://home.earthlink.net/~valleypoint/1987T_oscillator_circuit.jpg[/img] It turns out that the 68k resistor at the base was actually 680k!! And it was originally what Marsh...

Hi all, I'm new to this board...thanks for accepting my membership! :-) I am doing a restore on a friend's 1969 Marshall 1987T and I have almost everything running smoothly and up to spec. It sounds amazing...all except for the tremolo. The tremolo oscillates just fine and inserts itself into the ci...