Mods and tips for Fender Tremolo circuits

Here are a few tips and mods for the tremolo circuit in Blackface and Silverface Fender amps. These apply to the circuits with the light bulb/photo resistor trembug, not the tube based bias vary circuit.

Modding the tremolo to make it switchable in and out

I did this mod on my Bandmaster, and I love it. You get a noticeable bump in gain when you switch the tremolo out of the circuit. You can get the pot with the switch from Ted Weber.

Here's how it's done:
1. Disconnect the wires from the 50k RA Intensity pot.
2. Remove the pot.
3. Install new 50k RA Intensity pot with SPST switch attached.
4. Solder Brown wire to center lug as before.
5. Solder left lug to pot casing as before.
6. Solder Yellow wire to one side of switch.
7. Solder short length of new wire from other side of switch to right lug.

If you are getting pops when actuating the switch, add a 1 meg resistor inline with the yellow wire in step 6.

Slowing down the tremolo speed

If you're like me you think the speed control on Fender trem circuits is too fast. There are three caps in the trem circuit: Two .01's and a .02. You can slow the trem speed down by replacing the .01's with .02's. Tone wise, I don't think it matters here but I used Orange Drops.

Fixing the "Ticking" in Fender Tremolo circuits

This is from the great electronics guru R. G. Keen. For an astonishing amount of information about tube amps and guitar effects check out his website,

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