Gibson GA-18T Tremolo

[Blooze]

I’ve got my build up and going. Where would be the best location in the circuit to place a mini-toggle to shut the tremolo off? The way I have it wired now the connection goes from the speed pot to one end of a spst and the ground to the middle lug. The footswitch 1/4” jack is in parallel from there. The toggle does nothing on its own. With a footswitch plugged in the footswitch works if the toggle is in the off position.

I did try the original values for the trem and it would only occasionally kick in. I replaced the cathode resistor and cap with a red LED and that did the trick. Upped the caps to 0.02, 0.02, and 0.03. I tried 0.047 but the depth would drop out about 1/2 way up and the speed would stop the oscillation at 3/4 up. So with the current setup I have full speed control all the way through the sweep of the pot, with a speed typical of the original amps I’ve listened to online with the speed 1/3 up from zero. So it’s slightly slower. The depth kicks everything on at 1/4 on and works all the way through the sweep.

[sluckey]

With a footswitch plugged in the footswitch works if the toggle is in the off position.

That's exactly how it should work.

[Blooze]

With a footswitch plugged in the footswitch works if the toggle is in the off position.

That's exactly how it should work.

I guess I didn’t explain what I’d like to do very well. I’d like to be able to use the toggle to turn it on/off when I don’t have a footswitch. That doesn’t seem to work when the footswitch isn’t plugged in.

[sluckey]

I guess I didn’t explain what I’d like to do very well. I’d like to be able to use the toggle to turn it on/off when I don’t have a footswitch. That doesn’t seem to work when the footswitch isn’t plugged in.

Cut that jumper on the FS jack.

[Blooze]

Cut that jumper on the FS jack.

Between the ground and switch lug on the jack?  Just clarifying.

Have I said I hate switches. They always make me feel dumber than a bag of hammers.

[sluckey]

How many jumpers you got on that jack? Just asking.   

[Blooze]

How many jumpers you got on that jack? Just asking.   

Ha! 

Well, I couldn’t have done my first scratch build of a guitar amp without your help, so I definitely deserve a poke for asking questions that have simple answers if I’d just think a bit. The last two weeks at work with ISO audits have me fried.

[Blooze]

Yep. I got the amp all cases up and now the trem doesn’t work like it did earlier. I double checked all the parts values (270K, 68k, 510k, 2.2M, .33u, .033u, .022u, .022u). I only get a decent trem with the rate and depth knobs between 3-5 from zero on the dial.  The rate seems to max out on the LED at around 6 and I have to turn both the depth and rate back to zero to get it to kick in again.

Tried turning the MV all the way up to take it out of the circuit but that didn’t make a difference.

 

[AmberB]

I'm curious, do you have a tube shield on the tremolo tube?

[Blooze]

I'm curious, do you have a tube shield on the tremolo tube?

Nope.

[sluckey]

Does the LED quit flashing when the tremolo stops working? Turning the Intensity pot should have no effect on the LED flashing.