Wah with no bypass sound

[marcos_s_p]

Hey all!!

I'm new in the forum, although several times I've read threads from here before because I've been building a few pedals over the past. Anyhow, it's a really nice forum! Congrats!

It's been a while that I have a Vox v847 was pedal. Last week when I plugged it in I noticed that the effect is working, however when I turn it off to bypass, no sound is heard (or almost inaudible, still think there is no sound). I opened and everything seems to be in place (solder joints, etc). What can it be? I believe it is likely the switch? What do you think?

If that's the case, I have with me some dpdt switches, so instead of changing to the original I could use the dpdt and wire it up as a true bypass, right? Does anyone knows or have a working diagram for that?

I'm not sure If it is the right place to post, so correct me if I did it wrong.

Many thanks in advance!

Best,
Marcos

[wavley]

I'd say that it's pretty likely to be the switch and if you wiggle it around you should be able to get it to cut in and out.

[strungout]

Welcome to the forum!

For dpdt switch wiring: http://stinkfoot.se/archives/2233

[lukeferg]

Here's a link with a few pics to make it easier.
http://customguitarprojects.co.uk/?page_id=1034

[marcos_s_p]

Thanks guys!!! So, it is really likely the switch. I probably wire it up as a true bypass and if that's the case it should solve.

Another question though... I'm needing a volume pedal, and I've heard about a modification to this wah that would transform it in both, by just adding a simple switch. Do you guys know anything about it? I believe that even if it is true, I wouldn't be able to go to complete zero volume though. However, I hear that for the v847A model those mods are more difficult than for the v847 from the 90's. Mine is v847a by the way.

Many thanks again!

[R.G.]

Thanks guys!!! So, it is really likely the switch. I probably wire it up as a true bypass and if that's the case it should solve.

You may run into another issue if you convert it to true bypass. Sometimes the older pedals like the wah circuit will have a noticeable difference in level between the effect and non-effect switch settings. It may be fine, but just be prepared.

Another question though... I'm needing a volume pedal, and I've heard about a modification to this wah that would transform it in both, by just adding a simple switch. Do you guys know anything about it? I believe that even if it is true, I wouldn't be able to go to complete zero volume though.

It is true that the standard wah circuit originated by Vox in the 1960s can be converted into a volume pedal. For information on how and why this works, see "The Technology of Wah Pedals" at geofex.com .

The inductor wah circuit fundamentally is a "volume pedal", but it's used in a way to make the wah sound. You can install a simple switch to disconnect one of the resonating parts in the circuit, and the "volume-ness" comes through.

However, it makes a poor volume pedal. As you note, it cannot go to fully off. Worse yet, toe-down is lowest volume, not highest volume - it works backwards to what you'd expect. Best advice is that if you want a volume pedal, buy or make a volume pedal.

[marcos_s_p]

Thanks R.G.!

I´ll keep that in mind. Actually I just though of passing it to true bypass because I do have the DPDT switch and it would be shame using it as a SPDT. However, I might just do that because the v847a model if I´m not mistaken is buffered and hence shouldn´t change much the tone in bypass. I don´t know yet.

About the volume pedal mod, I´ll probably won't do it if it really performs badly. I'll wait to buy one or build. The problem in building I believe is the casing, which is more complicated than just for a regular pedal. I could by a cry baby that is burnt for that, but it is not that easy to find in good prices. As far as I saw they tend to be a bit salty for a non functioning pedal.

Anyways, many thanks again!