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Small Stone repair

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2/26/2004 9:49 AM

Small Stone repair

Tried posting this in the "Repair" forum but it seems most of the traffic hangs out here so sorry for the double post. Anyway, a buddy of mine gave me his old Small Stone to repair. As it is right now, it just tremolos. Does that indicate anything to any of you? I've replaced all the electrolytics. Didn't solve it. I've gone over all the wiring and it is as it should be. I'm hoping it's not the IC's but if so, I'll need the CA3094E, correct? In which case, hopefully, Steve'll have 'em in stock. This is the Issue J version, btw.
Could this possibly be a bad transistor problem?
Any help appreciated!!
Thanks,
Greg

2/26/2004 9:53 AM
Mark Hammer	By "tremolo" do you mean the volume goes up and down, or do you mean that you get a warbly pitch shift but no phasing? Clearly the LFO is working from your description, otherwise you wouldn't get any cyclical change. I assume the speed control works? I'd say repost over at Aron's DIYstompbox forum and you'll get more responses.

2/26/2004 11:46 AM
Greg	Okay Mark, thanks, I'll do that. But in regards to the tremolo, I would best describe it as the volume going up and down. But I'll double check it here shortly to be sure. Got furniture guys here at the moment.... : ) Thanks, Greg

3/17/2004 1:32 PM

Some stage in the phase shifting network is broken. I had the same problem with an old small stone... I was so lucky when i got one Spare 3094 IC.

The LFO was working, but not so much PHASE , almost just a weaker tremolo effect.

Try to use some sockets for the CA3094's. IF you can locate which chip is working for the LFO, you could use that socke in that position. Then changin ic's to the lfo section until the LFO goes off. That's an easy method to find which chip is bad. (easy if you don't want to trace back the circuit and check some voltajes)

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