I'm no stranger to the HM-2.....


I had a lot of fun designing this as a commission for a fellow HM-2 fan. I know it has been cloned to hell and back by lots of different designers but this one has some mods I haven't seen before; 18 volts headroom, series/parallel blend, 12 position cutoff frequency rotary, 8 hard and 8 soft clipping types for a total of 64 different clipping combos, three band EQ and a distortion circuit bypass to run other dirt pedals through the EQ section. 

Currently I'm in the process of building this one and testing it out, it's a bit of an undertaking even for an experienced builder. The rotary knobs are taller than the PCB mount pots so in order to make the pots fit flat against the enclosure they need to be soldered on the board almost at the end of their contacts so they are tall enough. Also there's some tight offboard wiring with the series/parallel 4pdt toggle switch that takes some finesse to install it neat and tidy. 

For all these mods I ended up going with 1590DD to house everything because the PCB itself turned out so large. I wanted to space out the rotary knobs for proper clear labelling also which allowed for all the adjustable settings to have space and not be crowded. The footswitch to kill the distortion circuit includes an indicator LED that turns on when the distortion section is engaged. 

I'll be posting some audio clips once the prototype is finished, I'm chomping at the bit to get it done and really excited to see the results. Right now the breadboard version I built sounds really good so I have high expectations for this to sound even better in PCB form. 


Back to blog

Leave a comment

Please note, comments need to be approved before they are published.