Crybaby + SD-1 = squeal

[ronh]

I got a problem with my Crybaby Wah and Boss SD-1 pedals. With the Wah into the SD-1 and both pedals "on" I have a squeal coming out as well as the guitar signal. The frequency of the squeal is varied by rocking the wha pedal. With the SD-1 off, I just get the wah sound. My SD-1 pedal has that faint clean sound in the background when it is on. The Crybaby wha has a buffer on its output. This wah, into a DS-1 doesn't squeal. Both pedals are powered from the same source which is regulated and clean. Anyone have an idea to solve this? Thanks in advance for any help.

[olddawg]

I got a problem with my Crybaby Wah and Boss SD-1 pedals. With the Wah into the SD-1 and both pedals "on" I have a squeal coming out as well as the guitar signal. The frequency of the squeal is varied by rocking the wha pedal. With the SD-1 off, I just get the wah sound. My SD-1 pedal has that faint clean sound in the background when it is on. The Crybaby wha has a buffer on its output. This wah, into a DS-1 doesn't squeal. Both pedals are powered from the same source which is regulated and clean. Anyone have an idea to solve this? Thanks in advance for any help.

Have you tried the obvious, using a different cord, guitar, and amp? Wierd capacitance in the cords could set up an resonance filter. It may also have to do with the gain of the amp and the band pass of the two pedals. Try a different dirt box and see if you still have the problem or another wah. The first thing is to find the source of the problem. If using a different Crybaby doesn't cause this problem, then the problem is the Crybaby. They aren't that complicated.

[ronh]

Fixed it

I fixed my problem but I dont know why the fix worked. I replaced D8 in the SD-1 pedal. This stopped the clean signal from appearing with the distorted signal out of the pedal. D8 connects to the gate of the first FET switch. Was it leaky or dropping more voltage? There was thread here awhile back about having the two signals out at the same time. Someone said it was because the FET was not turning off enough to stop leakage of signal. File this one under quick repair.