God City Instruments – HM-1 V1.0 Build guide
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GOD CITY INSTRUMENTS – HM-1 V1.0 Build guide
Inspired by the pedal stacking of early Swedish death metal pioneers, the God City Instruments (GCI) HM-1
combines the distortion and tone stack of a DS-1 with a boost-only version of the HM-2 tone stack.
For this humble pedal tweaker’s disertation on HM-2 philosophy please check out the Murdock Plus
build
guide
. The tone stack of the DS-1 is very similar to that of a Big Muff. Modifications for this are well
documented, and the
Duncan Tone Stack Calculator
is a great resource for tuning it to the desired response.
This pedal is an easy build, but this guide is intended for people who have some experience building pedals.
Component sourcing, component identification, assembly techniques, wiring stomp switches, etc. is not
covered. The GCI Brutalist Jr. assembly guide has helpful information for less experienced builders. That guide
can be found here:
http://www.kurtballou.com/brutalistjr/
Available separately is the GCI 3PDT utility PCB for PCB pin 3PDT footswitches. This PCB makes footswitch
wiring quick and easy. Not compatible with solder lug style switches.
Don’t forget to connect the ground pad of the PCB to the ground lug of the input, output, and DC power jacks!
Due to the scope of this project, technical support is not available. However, consider joining the GCI DIY PCB
Builders group on Facebook to get advice from and share your work with other builders. We require that all
group members agree to the rules before being accepted into the group.
https://www.facebook.com/groups/2454786551255317/
Component values for the PCB as well as some alternate values are listed below. This is a BOM for the PCB
only. Resistors and diodes are 6.3mm leg spacing, film and ceramic capacitors are 5.08mm leg spacing, and
electrolytic capacitors are 2.54mm leg spacing. I/O jacks, DC jack, switch, enclosure, and knobs are not listed.
The schematic and a drill template for a 125BB (1590BBM) enclosure are also attached.
