marksescon
Active member
I used this schematic that I redid from FSB. Gray Bench Electronics also did a teardown of the pedal that showed a few variances like the Bass potentiometer (C500K -> C1M) and the Gain potentiometer (B100K dual gang -> A100K dual gang) and JFET selection.
PCB was designed in Eagle. I did do a version to allow for SMT JFETs; however, the SMT versions of the JFETs are not available at this time. I opted for a J201 for the first JFET sourced from PedalPCB and 2N5457 for the other JFETs sourced from StompBoxParts. I also changed all the trimmers to 50K because the 10K on the Bias control didn't allow me to adjust the voltage appropriately. I put some "empty pads" on the PCB so I could easily adjust the voltages with my multimeter probe. Chuck's insight about biasing JFETs and this runoffgrove article helped with the biasing of the JFETs.
I built this in a 125B Pro from StompBoxParts. I highly recommend it; it's legitimately one of the best looking plain aluminum enclosures I have ever seen. My drilling was a bit off and I had to drill bigger potentiometer holes to allow for more "play" to allow better positioning, but I think it turned out fine. Graphic art is from Daiso, a Japanese dollar store in my area.
If you are interested in building your own, here are the free Gerber files with build instructions: https://github.com/marksescon/themini. I removed moniker from the PCBs as well.
PCB was designed in Eagle. I did do a version to allow for SMT JFETs; however, the SMT versions of the JFETs are not available at this time. I opted for a J201 for the first JFET sourced from PedalPCB and 2N5457 for the other JFETs sourced from StompBoxParts. I also changed all the trimmers to 50K because the 10K on the Bias control didn't allow me to adjust the voltage appropriately. I put some "empty pads" on the PCB so I could easily adjust the voltages with my multimeter probe. Chuck's insight about biasing JFETs and this runoffgrove article helped with the biasing of the JFETs.
I built this in a 125B Pro from StompBoxParts. I highly recommend it; it's legitimately one of the best looking plain aluminum enclosures I have ever seen. My drilling was a bit off and I had to drill bigger potentiometer holes to allow for more "play" to allow better positioning, but I think it turned out fine. Graphic art is from Daiso, a Japanese dollar store in my area.
If you are interested in building your own, here are the free Gerber files with build instructions: https://github.com/marksescon/themini. I removed moniker from the PCBs as well.