this is one of my favorite overdrives. With a dark smooth tone, it’s really an overdrive, rather than a low gain distortion. It really never goes into hard clipping which gives it an expressive dynamic range. I built this from a Procyon PCB from AionFX. I used a desktop mill to engrave the labels and logo on the enclosure.
Great overdrive/distortion with good dynamics and clarity cleans up well with volume knob. You can buy this one at my Reverb Shop. Or, build your own! Order PCBs from OSH Park and follow the build doc.
This UBE Screamer by RunOffGroove.com is a unique twist on the venerable Ibanez Tube Screamer TS-808. It replaces the op-amps and transistor stages with a single hex inverter using an inverter in place of each op-amp and transistor. This has a great sound that stands up to all of the other overdrives. Read more about it over at RunOffGroove.com
Well worth the effort, build it yourself! I’ve created a public project at OSH Park. Order boards and follow the build docs.
This is Joe Davisson’s Vulcan overdrive. Starting with a prototype board made at home with the Othermill, then turned this into a board from OSHPARK. Boxed up and is working well. This is an interesting overdrive with a couple unique circuit features.
There was no documentation on OSH Park for this, so I reverse engineered the board to match the parts in the schematic. Here is the schematic I used with part numbers that match the PCB.
Overall the board turned out pretty good. I used a socket for the dual op-amp. I threw a random 1458 in that was sitting in a pile of parts on my bench, and it fired up first test. This is supposed to use a JRC 4558. I think I have a couple of these squirrelled away, I’ll dig them out before I box things up. I might try some other op-amps also.
There are three sets of diodes. D2-4 are Ge, D5-6 are Si, and D7-8 are LED. I used some 1N34 for the Ge, and 1n914 for the Si, and random 3mm LEDs from the parts bin.
With 3P4T switch the circuit is only using one pole. I only soldered the pins used by that pole. This way if I made a mistake, it’s been known to happen, I had fewer pins to de-solder. With these switches there is a small ring with a tab under the nut. Be sure to set this for four positions.
To mount the pots, I would suggest making a box first, mounting everything in the box. This will position the pots at the correct height above the board compared to the switch. Then solder from the top of the board. I made some holes in a piece of cardboard, and mounted everything in that before soldering, since I didn’t have a box drilled yet.
I put everything on the test rig, and it fired up first! Good for me, and thanks to bmossma at OSH Park. It’s always inspiring when things work on the first attempt. The sound was pretty good, it didn’t sound like much with guitar, with bass, the effect started to make sense. I tested with my baritone guitar and it seemed to sound pretty good with that also. Definitely more of an overdrive, distortion, than a fuzz to my ears.