MXR 118 Repair

Started by zwkelly, March 05, 2021, 06:31:31 PM

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Hello everyone,

I too purchased a non-functioning MXR118 delay pedal. It's the Reticon 5101 version. I managed to find a replacement Reticon chip. I have changed all the box caps and all the chips (now with sockets). After the chip swap, I can finally hear something that gives me hope in fixing this pedal. Here's where the issue lies - the pots don't really do anything (will explain). The delay knob seems to change the pace of the delay (but without that slowing down effect when you drop from fast to slow); the mix knob seems to come undone with noise in any position beside 0 and 10. The Regen does what it should do, no problem. I can hear this, but the entire mix is extremely dark... What are your thoughts on changing out the pots? Perhaps the tantalum caps as well? I haven't ever touched the trim pots either (and don't know if they've been messed with prior to getting the pedal).

I'm just looking for suggestions in which direction I should take this project. There's no deadline for fixing this, but I truly believe it is fixable (even if it's not worth it once I'm all done). If you want pictures or recordings, just let me know, and I can provide them.



That seems like a cool project.

I am not quite sure what you mean by the mix knob coming "undone", but it might be worth trying to clean them before replacing them.

When you say the mix is extremely dark, do you mean the dry signal as well? If just the delay signal, I would think that is related to one of the trims.

Do you have a schematic for it?