I've tested it with a know good battery. I've tested it with the Boss PSA.
The delay sound is distorted, but the normal sound comes through. The feedback knob doesn't work well: when I keep it under 9 o'clock, it does only one repeat. When I turn it up, it starts to oscillate (at one frequency, which I can change with the time knob).
I guess the problem should be somewhere in the feedback circuitry. I have access to an oscilloscope & wave generator.
The bottom left corner of the board looks burned. The diode above (D6) looks swollen. I'll try to take some pics tomorrow.
Edit: I forgot to mention: it's a MIJ one. So I guess the schematic looks like the DD-2?
We've seen ths a lot lately... it is almost certainly the capacitors around the NE570 compander. Can't recall which ones, but I'll look them up tonight when I'm home from work.
What's happened in the other pedals is that the compressor part of the comapnder stops compressing, so you have a never-ending loop of increasingly expanded repeats - sounds like distorted, oscillating mud.
Oh... and your description of D6 is pretty standard. Maybe it is still working though because they normally fail "short" and shut down the pedal completely.
Broken DD-3
Posted - 03/17/2010 : 20:26:10
