Fulltone chorusflange CF-1 broken

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Gizmoaudio
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Joined: 18 Apr 2015, 04:18

Post by Gizmoaudio »

I tried contacting Fulltone but their website no longer accepts emails. I heard a rumor that they went out of business?

I'm troubleshooting this pedal for a friend who just purchased it used. There are two op-amps in it are fried. Someone else said these are JRC4558D's. You can hear the effect barely when in non-bypass. The Fulltone manual says there are two modes of operation, true bypass and buffered bypass that can be selected with DIP switches. It warns that the unit will be damaged if the DIP switches are changed when the power is on to the pedal. I'm assuming this is probably what happened. The fact that we can hear the effect but with extremely low volume makes me think these are the buffers and they got damaged. I can trace out the circuitry but will try just swapping out the op-amps to see if that fixes it first. Has anyone ran into this issue before? Any ideas on the buffer switching circuitry that Fulltone used in this design? Or does anyone have a schematic?
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good opamps.png
burned opamps.jpeg

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CheapPedalCollector
Resistor Ronker
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Post by CheapPedalCollector »

It's not a rumor, Fulltone has closed it's doors.

NE5532 is a better choice. Sockets are probably fried too, and maybe some other parts around are stressed.

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