I have a certain fondness for old DOD pedals. They’re fun, many of them are terrible in quirky ways, and there are some gems that are actually pretty good. Plus, even though the weird collectors’ market has driven the prices of some of them pretty far above what they’re really worth, a lot of them can still be found for pretty reasonable prices. I don’t have a huge pedal collection, but a few old DOD pedals have certainly found their way in over the years.
While I was in grad school, I mostly stopped playing guitar, so most of my guitars, pedals, and amps spent those years in storage. Since I’ve started playing again, I’ve also been trying to make sure everything is working as it should be, and two of my old DOD pedals, the FX50-B Overdrive Plus and FX75 Stereo Flanger, weren’t.
The two pedals in question
The FX50-B is an overlooked gem. The circuit, as far as I know, is based on the DOD 250(/MXR Distortion+), one of my favorite overdrive circuits, with some added buffer and tone circuitry. I paid around $20 for this one, but that was 15 years ago, before I was even in grad school. They’re still going for around $50, although the footswitches on this series are terrible, so I would suspect a lot of them aren’t totally functional.
When I plugged it in after taking it out of storage, it wasn’t working at all. No signal passing through to the amp whether the effect was on or off. The most obvious problem when the pedal isn’t passing signal at all is that it isn’t getting power, but since it would turn on and off I could rule that out. Likewise, that ruled out a footswitch issue, which would otherwise be my first thought with this series. I ruled out some of the other obvious possibilities, like bad cables or the amp volume being too far down, and decided to open it up and see if I could figure out the problem, since I was going to be cleaning it anyway. Since the pedal wasn’t passing any signal to the amp whether on or off, one possibility was a grounding issue. If some part of the circuit that shouldn’t be grounded is touching the case, the pedal just won’t make any sound. This didn’t seem likely, since it was working before I put it in storage, but I figured it was worth testing, so I (carefully) pulled the circuit board away from the case and tried again. Still nothing, so that wasn’t the culprit. Since the circuit board was out, I figured it would be worth looking at the wires that run from the bottom of the board to the potentiometers, jacks, etc. These are pretty fragile, so they seemed like possible culprits, but they all looked good. My next thought was that some component had failed, which wouldn’t be unheard of on a cheap, decades old pedal, but everything looked fine, and the diodes and pots all tested good with a multimeter. This was a little weird. Everything seemed fine, but the pedal still wasn’t working, so I decided to give it a good cleaning and then revisit the problem. I had noticed that the jacks looked a little rusty (this should have been a clue), so I gave both of them a good scrub with a wire brush, and then something clicked in my head and I decided to test it again. Yes, the jacks were so dirty that they hadn’t been making good contact with the cables, but the pedal was fine otherwise. So now it works again, and it’s a lot cleaner, too.
The flanger had a weirder problem. It was turning on and off and passing signal, but it wasn’t… flanging. When the effect was on, it was just making a weird, high-pitched whining noise. I opened the pedal up and quickly started to suspect that the three trimpots on the circuit board might have something to do with the problem, so I started adjusting them. I managed to find some pretty fun settings, including one that sounds a little like a ring modulator, but after playing around with them for a long time, I was never really able to get it to sound all that good. I eventually settled on some positions that do give a flange effect, but it’s pretty weak. I’m not sure if something else is going on (all of them components look fine, though) or if the pedal just doesn’t really sound very good. I’ve seen some demos that manage to get nice flanger sounds out of it, so I might try to play around with the trimpots a little more one day to see if I can get it back to being a decent flanger, but who knows, I might just go back to the weird ring mod sound, too.