Sano Hi-Fi Stereophonic Amp / KT77 Genalex Gold Lions 1962

[plexi50]

I have a tremelo problem. It doesnt work. I have read that the tremelo only works on the Stereo portion of this amp. I have clipped onto the 4 pin stereo jack with the guitar and get guitar signal but still no tremelo. When i stomp on the trem footswitch i hear a pop. I was thinking bad caps so i changed all the old green caps and trem caps out for new ones. All resistors in this amp read  within 10% of there value. Does anyone have any experience with this amp?

[sluckey]

Find and post a schematic.

[plexi50]

Find and post a schematic.

I have all the Sano schematics except for this one. This amp has no reverb but here is a pretty close schematic though im not sure about it either

There is no transistor in this amp (2N2497)

[Tiny_Daddy]

Can you tell if the trem oscillator is running? You should be able to see it with a scope or analog meter.

[sluckey]

ROTATE THE SCHEMATIC SO THE TUBE PLATES ARE AT THE TOP AND CATHODES ARE AT THE BOTTOM!

According to page 2 of that schematic, the trem is only applied to one of the stereo inputs. It's not applied to the other stereo input, nor the guitar input, nor the instrument input. The trem oscillator is the 12AX7 just to the right of the tremolo gain pot. The trem signal is applied to the 2N2497 FET. The FET is used as a variable resistor in series with that 25/25 cathode bypass cap for the 12AX7 at the top left of the schematic. This will vary the gain of that 12AX7 at the trem rate.

Divide and conquer. Make sure the trem osc is oscillating. Then make sure the trem signal gets to the cathode of that stereo preamp tube, ie, varies the cathode voltage. An analog meter would be helpful. You don't need the footswitch.

[plexi50]

Thanks Steve. This amp dose not follow that schematic. I thought it was close enough but it isnt anything like the tremelo circuit in the schematic i posted. Im searching and tracing now