Any wah's with 10k wah pot?

[mth5044]

I have a soft pot that goes up to 10k that i was going to use for a wah circuit with a synth type instrument. Most wah's seem to use 100k. Any that are only 10k?

Thanks 

[Paul Marossy]

I have a soft pot that goes up to 10k that i was going to use for a wah circuit with a synth type instrument. Most wah's seem to use 100k. Any that are only 10k?

Thanks 

The smallest I have seen is a 25K pot in the Maestro Boomerang.

[mth5044]

Hmm that will not do. Thanks for the input 

[R.G.]

The exact pot value is immaterial in a wah as long as it does not load down the collector of the first transistor. Unfortunately, much less than 50K *does* load it down.

What you can do is buffer the collector of Q1. Just connect a high gain NPN like a 2N5088 (note to longtime readers: what a surprise!) with its collector to +9, base to the collector, emitter to ground through a 10K resistor, and take the cap which used to come off of Q1 collector from the emitter of the new transistor instead. Now you can use a 10K wah pot. You will probably need to up that 0.22uF cap that used to be from the collector of Q1 to about 2.2uF to avoid bass loss because your new pot loads down the cap too.

[Paul Marossy]

The exact pot value is immaterial in a wah as long as it does not load down the collector of the first transistor. Unfortunately, much less than 50K *does* load it down.

What you can do is buffer the collector of Q1. Just connect a high gain NPN like a 2N5088 (note to longtime readers: what a surprise!) with its collector to +9, base to the collector, emitter to ground through a 10K resistor, and take the cap which used to come off of Q1 collector from the emitter of the new transistor instead. Now you can use a 10K wah pot. You will probably need to up that 0.22uF cap that used to be from the collector of Q1 to about 2.2uF to avoid bass loss because your new pot loads down the cap too.

Huh, that's a cool trick to put in the files! 

[mth5044]

Hey, thanks R.G.! I really appreciate it. 

[David]

mth:

Please let us know how this works.  That soft pot could be another tool in the wah pedal construction arsenal.

[mth5044]

It will actually be a while until I start it. I just wanted to get it out there and see what we had to use. I'll write it on my board so I'll remember to let you guys know how it goes!