Zeke Bass Distortion – OSH Park

This Zeke Bass Distortion is a clone of the D*A*M Ezekiel 25:17 Bass distortion. The PCB came from OSH Park. This worked out well. The board is pretty big so soldering parts is easy. The rotary switch and pots are all mounted on the board, which makes assembly easy, this is a good PCB.

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.

zeke

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.


IMG_1178.JPG

IMG_1179.JPG


Bass Overdrive

This is a bass overdrive built from PCBs from GuitarPCB.com. The boards were professionally made. The layout is good, with pots mounted to the PCB. The  LED is also mounted to the PCB. Actually everything goes through the PCB, except for the ground wire from the battery clip. The system seemed to work well and makes for an easy wiring job.

The boards included a system to use a bi-color LED. With a single red/green LED, the LED would show red when the effect was on and bypassed, and show green when the effect is engaged. While I appreciate the ingenuity, I didn’t choose to implement this feature. I feel if the light is on I’ll think the effect is engaged. Everything else I have works this way.

The build was pretty easy. I used parts I had on hand. This build doesn’t use any non standard parts. This effect relies on overdriving JFETs. Using two MPF102, and a single 2n5457. Nothing too special the claim is carefully chosen caps make the system work well with bass.


FET Driver

This is Tim Escobedo‘s FET Driver.

FET Driver

FET Driver 2