fsh-1 quit...any ideas?

Started by vacuumdust, July 23, 2008, 06:15:33 PM

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vacuumdust

I know this pedal gives people lots of problems...thought I had it licked.  I've built 5 of them and they all worked great but this has happened twice now.  While trying to eliminate whine and ticking problems(.0047 cap across pins 5 and 6 of IC4 eliminates the whine...no ill effects, keep the output jack tip lug and wire as far away as you can from the board) I must have shorted something out...at least I solved the noise issues before it went to hell:)  Bypass works fine...when engaged there is a volume drop, it passes signal but it's in a high frequency range and there is no wah or sample and hold going on.  All voltages check out, i've replaced all IC's and diodes, checked my electrolytics...the only thing I haven't tested or replaced are the jfets...but I think if any of those died it would be completely dead.  Any ideas??  THANKS 

returntable

could be one of the jfets. I had a similar problem, replaced them and now everything is fine again :)
"the earth is not a flat screen"
-Saul Williams-

vacuumdust

Unfortunately the only fets I have are MPF102s.  As long as I get the pinouts right...they might work enough to at least let me know if that was the problem.  THANKS

returntable

"the earth is not a flat screen"
-Saul Williams-

vacuumdust

It ended up being the 2n3906...figured it out after replacing the jfets with 2 mpf102's and a 2n5457.  The 102's and the 5457 work well AND they are the correct pinout for the GGG circuit board.