VOX 1904 Wah - how to mod for True Bypass?

Started by Cortex, October 03, 2012, 04:51:25 AM

Previous topic - Next topic

Cortex

Hi people, by sheer luck I've had this AMAZING pedal in my collections for several years, I love it, no modern envelope filter comes close, at least for me.

BUT....since I am a major Fuzz Face user, placing this pedal before the FF is a no go. Not just that it completely kills the FF's sound, it's killing my signal, it reduces treble a lot, and also volume, I checked this by placing the 1904 Wah in a separate TB loop. So, naturally, I wanna make it true bypass.

This is the schematic
http://www.voxamps.com/downloads/circuits/1904wah.jpg

I really don't know where to begin honestly...please help me make this true bypass people! I really like this pedal over all others. Cheers.

Cortex

Of course what I COULD do, which is the stupidest thing ever, is to just leave the existing switch [cause it's tiny] inside the pedal and just lift the wires from the jacks and wire them to an additional switch and that way have the 3pdt true bypass functionality as well as the possibility to return the pedal into it's original state in a minute.

But that's a very stupid way to do it, and I'd rather not do that :)

Liquitone

But wouldn't you have to drill a hole in the enclose for that 2nd switch? :P

How big is the room inside the pedal?, are the switch and jacks mounted on the pcb?
If the pcb is in the way of a bigger 3pdt switch but connected to the switch by wires you could use a dpdt relay.
The advantage of that is that you can stuff the relay anywhere where there is room inside the box and still use the existing switch to turn the pedal on and off. (and keep the LED)

Simply leave the switch's connection to the LED as it is. connect v- of the relay to the existing switch where the enclosure's output would have been. and solder a jumper on the switch to the side that also pulls the ON LED to ground.
Connect the fx in/out and the enclosure in/out to the relay the same way as you would on a 3dpt but without the 3rd row for the LED.
steal some voltage from the circuit to the relay. 

you will probably need to make a little circuit on a vero to connect the relay to the wires if you want it to be sturdy, but it give you some flexibility with fitting it in the box, and you can easily revert the pedal to it's original state this way.

Liquitone

p.s. you might need some additional parts for the relay to operate properly and without unwanted pops. like a diode in opposite direction of the v+ and v- connection of the relay to prevent damaging it with voltage spikes.
im just learning about relay switching so still looking into it.