How do I add noise filtering to a wah pedal?

1wahfreak · July 21, 2009, 10:38:24 PM

I have a homebrew wah pedal I made from a few non working vintage pedals. I think it sounds great but it has some inherent noise associated with it. It's an annoying 60 Hz hum.

I have a well known production pedal along side it that doesn't have this problem. There's an extra electrolytic cap on the board but I have no idea if that's what it's there for.

First, where does come from and is there away to minimze this??

Thanks

ACS · July 21, 2009, 10:55:40 PM

Could try the beavisaudio Huminator

blueduck577 · July 21, 2009, 11:45:03 PM

try powering it with a battery and see if that helps. if it helps, the noise is coming from the AC adapter and the huminator above might do the trick.

aziltz · July 21, 2009, 11:46:20 PM

it sounds like you're missing the big (100uF) power filtering cap. Try putting one between the 9v in and ground.

Paul Marossy · July 22, 2009, 09:51:50 AM

If it's coming from the power supply, it would be a 120Hz hum/buzz. The 100uF cap should take care of that.
If it's not due to the power supply, then it's probably EMI being picked up by your inductor, which would be in the 60Hz range.

1wahfreak · July 22, 2009, 12:24:09 PM

It's powered by a battery and it's definately 60Hz. It's the same annoying sound as my single coils. I should really invest in the Suhr SSC system.

Any suggestions on how to reduce it?

Paul Marossy · July 22, 2009, 12:45:59 PM

Quote from: 1wahfreak on July 22, 2009, 12:24:09 PM
It's powered by a battery and it's definately 60Hz. It's the same annoying sound as my single coils. I should really invest in the Suhr SSC system.

Any suggestions on how to reduce it?

Sounds like it's the inductor picking up EMI to me, it's similar to a single coil pickup in terms of being sensitive to EMI.

What if you move the pedal to another location? Will it still behave that way? Some of my wah pedals go crazy with hum when they are anywhere near a wall wart (or a series of them).

newfish · July 23, 2009, 05:34:17 AM

Would better shielding help at all?

Just a guess.

Paul Marossy · July 23, 2009, 10:10:12 AM

Quote from: newfish on July 23, 2009, 05:34:17 AM
Would better shielding help at all?

Just a guess.

It's already shielded the best it can be by being in a cast metal wah pedal shell...

Ripdivot · July 23, 2009, 11:07:29 AM

Quote from: 1wahfreak on July 22, 2009, 12:24:09 PM
It's powered by a battery and it's definately 60Hz. It's the same annoying sound as my single coils. I should really invest in the Suhr SSC system.

Any suggestions on how to reduce it?

I have the Suhr system on one of my strats and it works great. I have Kinman pickups in another strat and they sound great as well. I like the Kinmans and would go that route. They are about the same money as the suhr system.

Paul Marossy · July 23, 2009, 11:54:36 AM

Quote from: Ripdivot on July 23, 2009, 11:07:29 AM
Quote from: 1wahfreak on July 22, 2009, 12:24:09 PM
It's powered by a battery and it's definately 60Hz. It's the same annoying sound as my single coils. I should really invest in the Suhr SSC system.

Any suggestions on how to reduce it?

I have the Suhr system on one of my strats and it works great. I have Kinman pickups in another strat and they sound great as well. I like the Kinmans and would go that route. They are about the same money as the suhr system.

That works great for your guitar. But it doesn't do anything for you if the noise is getting into the system elsewhere (like thru a wah inductor for example).

I have some Fender "Hot Noiseless" pickups on the neck and mid positions of my guitar (DiMarzio FRED on the bridge), I really like them. I can get seven different distinct tones out of my guitar between the five way pickup switch and the coil tap switch. They are very quiet pickups and these noiseless pickups I think sound very good - like a hotter wound single coil, but without that blasted HUM.

1wahfreak · July 23, 2009, 01:16:09 PM

Thanks for the suggestions. I'm just trying to figure out how the other one can be so much quieter. I did notice the output on mine is slighy higher, but even if I fix that, it still won't reduce the hum. It's not terrible and something I could probably live with but I just want to get it better.

I just bought a wipple and A/B'ed it between an Arial/FX, and 5103, a film can, and an '03". I kept the wipple in there. The wipple and the Arial sounded identical to me.

The production model inductor is coated with something. I don't know if thats functional or just goop. I do have some conductive copper tape that I could mess around with. I wonder if wrapping it around the inductor would help.

Paul Marossy · July 23, 2009, 02:05:37 PM

Quote from: 1wahfreak on July 23, 2009, 01:16:09 PM
The production model inductor is coated with something. I don't know if thats functional or just goop. I do have some conductive copper tape that I could mess around with. I wonder if wrapping it around the inductor would help.

Might help to shield the inductor. But I wonder if it would affect the frequency response a little bit? It would kind of be like one of those metal covered humbuckers then...

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How do I add noise filtering to a wah pedal?