madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: jtn191 on March 17, 2012, 04:24:39 PM

Title: help fixing a wah?
Post by: jtn191 on March 17, 2012, 04:24:39 PM
Hey, I don't have any experience with wahs and so I think the inductor on mine has me a bit baffled.
Here's the story:

I bought a "broken" wah--Cry Baby GCB rev G-- from a guy on BYOC, intending to put my own wah circuit in it. He says he modded it (changed a few resistors and caps) and it was working fine until he dropped it. Now it acts like a volume pedal. I got bored last night and decided to fix it. From the underside, everything looks fine--all clean soldering, no glaring problems. I first checked the 4.7uF electro because problems with that one is supposedly likely to turn a wah into a volume pedal--but it's going to ground just fine. Someone suggested the inductor might be faulty due to the drop...I measured 160k ohms between the pins not touching on it. My audio probe showed that the volume effect was present on the base of Q1

my board looks like this one
(http://i.imgur.com/irKzL.jpg)
Title: Re: help fixing a wah?
Post by: jtn191 on March 21, 2012, 05:15:02 AM
bump...anyone know about faulty inductors?
Title: Re: help fixing a wah?
Post by: jkokura on March 21, 2012, 05:19:25 AM
dropped it? Indicates broken solder joints to me...

Jacob
Title: Re: help fixing a wah?
Post by: Davefx on March 22, 2012, 09:43:53 PM
Check the area where the 4.7uf cap is. When these go bad, it acts like a volume pedal.  So could be a broken trace possibly in that area of the circuit, like Jacob said.

Dave
Title: Re: help fixing a wah?
Post by: jtn191 on March 23, 2012, 12:00:24 AM
Quote from: jtn191 on March 17, 2012, 04:24:39 PM
I first checked the 4.7uF electro because problems with that one is supposedly likely to turn a wah into a volume pedal--but it's going to ground just fine.
Title: Re: help fixing a wah?
Post by: Davefx on March 23, 2012, 03:59:14 AM
Jesus.. My bad.. sorry.. ADHD.. Just when I thought I would help someone.. :P
Title: Re: help fixing a wah?
Post by: timbo_93631 on March 23, 2012, 05:50:00 AM
If the inductor has a broken solder joint it'll act like a volume pedal, I'd check there.  It would be weird to get a reading of 160k across the pins of the inductor, should be like 15-20ohms