Fender Blender - Volume bypass switch

[Paul1985]

I want to try and mod my blender fuzz that I built a little while ago. the goal is to create a volume bypass that when engaged it sets the volume to max. Kind of have a rhythm volume then a lead volume. II believe the steps required are

Wiring Steps:​

1. Circuit Output to Switch:
   
   • Connect the circuit output to the top left terminal on the DPDT switch.
2. Volume Pot Wiper to Switch:
   
   • Connect the middle lug (wiper) of the volume pot to the middle left terminal on the switch.
3. Switch to Output Jack:
   
   • Connect the output jack to the bottom left terminal of the switch.
4. Bypass Connection:
   
   • Create a direct connection between the top right terminal and bottom right terminal on the switch to bypass the volume pot entirely when switched.
5. Ground Connections:
   Ensure the volume pot ground remains connected to the circuit ground as it does not change during bypass.

My question is should i remove the circuit output from the main switch just to the new switch. And would i just run a patch wire from the wiper lug to the switch.

 

[Feral Feline]

That's not going to work.

That's not how DPDT switches work.

DPDT = two poles of stacked lugs:

POLE A
1—
2—
3—

POLE B
—4
—5
—6

TOGETHER, the DPDT:
1— —4
2— —5
3— —6


Your point #4 says to connect lugs 4 and 6. Then you won't be switching anything on that pole.

Here's a bunch of DPDT switches of various types, they show how POLE A and POLE B connections go up or down together.





KISS IT BETTER
Here's a simpler idea for maxing out your VOLUME/LEVEL, and you could do it with just a SPST toggle, but if I understand correctly you want a DPDT-stomper and using the 2nd pole for LED-indication.

Run a wire from LEG-3 of the LEVEL pot to your DPDT's LUG-2.
Run a 2nd wire from DPDT's LUG-1 to LEVEL's LEG-2.
Wire up your bypass LED to the remaining pole.
Let me know if you want a diagram of this simplest of solutions, I can whip one up for you.

When the switch is connecting LUGs 2 & 3, you've got your stock LEVEL pot.
When the switch connects LUGs 2 & 1, you've lost all LEVEL control as it's on full blast.







STILL TOO LOUD?
What if full blast is still too much? Then off-board wire 2xLEVEL and switch between them:






Now it's best to have a 3PDT to retain that LED indication:







You could even wire up one of the pots as an internal trimmer, so you can tweak it to taste without having to drill an extra hole for a second knob.
There's even a PCB for this very sort of thing over at GuitarPCB, it's called the 2KnobJob.
You could do all this on perf, but the price for the PCB is reasonable though you'll want to make shipping worthwhile — so see what else Barry at GPCB has got.



Wire the 2knobjob up with 2 pots, or a pot and a trimmer, or 2 trimmers for that matter — you could even wire up a pot and a fixed resistor, but... why? Just use the trimmer instead of a fixed resistor.

Hope this helps.

 

[Paul1985]

Thank you very much
If you could show me a diagram of that option with the DPDT switch with led that would be amazing

 

[Feral Feline]

Thank you very much
If you could show me a diagram of that option with the DPDT switch with led that would be amazing

You don't even have to remove the LEVEL pot from your build.
Just add the wires and DPDT as shown to go from the LEVEL-pot setting to FULL-BLAST.
If you need to tame full-blast just a smidge, you can stick a resistor inline between the pot and the switch, either
SW LUG-2 <> LEVEL-3
or
SW LUG-1 <> LEVEL-2.