MXR M118 Analog Delay v1 SAD version not working properly

[OosterhoutW]

Dear reader,

I have some bad news. My MXR M118 delay stopped working. It has the three SAD chips and is the V1 mono version.

Whats wrong: the mix knob works kind of like a blend knob that blends wet/dry signal.
When the delay is turned on and the mix knob all the way to the right, there is 0 dry signal (which is normal) but also only a very feint, dark mushy delay sound. Not the full analog experience, if you will.
I have no idea what the problem might be. Bypass works 100%, if you turn the knob all the way down (to 100% dry) it works properly, so 0 delay mix = 100% dry sound, no weird eq changes.

I reseated the SAD chips and that didn't do the trick. I'm European so I have two transformers to regulate the powersupply. I am in the process of checking those.

Could anyone help me...?

Cheers! Will make pic's later.

[StephenGiles]

Bad luck, in what way has it stopped working?

[Kevin Mitchell]

Bad luck, in what way has it stopped working?

When the delay is turned on and the mix knob all the way to the right...... only a very feint, dark mushy delay sound

Did you mess with any of the trimpots in there?
Sounds like signal going into the first BBD isn't biased properly or perhaps one of the BBDs are starting to deteriorate, which would be very unfortunate considering how the pedal isn't worth the current asking price of a replacement SAD1024 chip.

An audio probe and readable schematic is what you need.

[ElectricDruid]

An audio probe and readable schematic is what you need.

Even without the readable schematic, with just a SAD pinout they might be able to find out if they've got delayed signal from some or any of the chips. That would help. It might be that you could get the thing running properly with somewhat shorter delay times by removing the faulty chip, for example. I totally agree that the audio probe is going to be essential though!