Tubescreamer Fat Switch w/ Lift

[LabyrinthAudio]

Everything on my GGG ITS8 pedal works correctly except this. I hooked up a 3 position SPDT ON-OFF-ON toggle switch for a cap on each end and a lift, or bypass in the center position, just like the clipping diode switch. The center position on the fat mod switch doesn't work, it bypasses the entire signal. I soldered it according to the beavis audio diagram. Any ideas? If the diode switch works then this should work... Any insight would be greatly appreciated! Thanks!

[PRR]

Which cap? C3? If this is open, then IC1a runs flat unity-gain, which is nearly no effect at all.

Put your smallest cap permanently at C3. Perhaps 0.02uFd. This is what you get in center OFF. Only the very-highs are boosted.

On one ON side of switch connect a larger cap, perhaps 0.05uFd. In this position you have 0.02u+0.05u= 0.07u, more bass than stock.

The other ON side, put a jumper. This side gives the AMZ "Fat" mod, all bass. If this is too boomy for you, try 0.1uFd instead of jumper.

I'm picking these cap values without knowing the sound of the pedal or the sound you want. You will want to experiment. Remember the center-OFF position must be your "brightest" tone, the other two are more-bass positions.

[LabyrinthAudio]

Which cap? C3? If this is open, then IC1a runs flat unity-gain, which is nearly no effect at all.

Put your smallest cap permanently at C3. Perhaps 0.02uFd. This is what you get in center OFF. Only the very-highs are boosted.

On one ON side of switch connect a larger cap, perhaps 0.05uFd. In this position you have 0.02u+0.05u= 0.07u, more bass than stock.

The other ON side, put a jumper. This side gives the AMZ "Fat" mod, all bass. If this is too boomy for you, try 0.1uFd instead of jumper.

I'm picking these cap values without knowing the sound of the pedal or the sound you want. You will want to experiment. Remember the center-OFF position must be your "brightest" tone, the other two are more-bass positions.

Thanks for the response PRR! I've been messing around with this for hours and still can't get it right. I have C3 in place on the board @ the stock .047uf. Switch lug A is hooked up to one leg of C3, then Lug C is hooked up to the other leg of C3. I got a jumper on lugs A&B, then a .1uf cap on lugs B&C. Position B&C works (.1uf), middle position B works, but A&B has the same effect as the middle position. Any ideas?

[PRR]

My bad. I should not try to describe circuits in words.

[LabyrinthAudio]

Thanks for your help PRR. I got it to work but the third position isn't working! I checked all connections and they're good. I'd like that third position to be full bass.

[Seljer]

I'm not sure if can see right but the extra capacitor should be connected to the outer lugs and the the to/from circuit wires to one of the outer lugs and the middle lug of the switch

[LabyrinthAudio]

Yea sorry that pic was at a tight angle and also sloppy soldering Right now the cap is connected to the middle and right lugs with a jumper from the middle to the left lug. Thanks Seljer, I'll give that a try soon.

[LabyrinthAudio]

Seljer, it worked thanks!!! Also thanks PRR.