GHR Audio

Posted: **Tue May 20, 2025 4:41 pm**

These are the Gerbers for the 12-step coarse (Lorlin 1x12) and 23-step "finer" coarse (Elma 04 1x24, set to 23) gain switches that I used in my Transformerless VariMu build. Also attached are the schematics.

LR_Heikki_12-Step_Gain_Schematic.pdf: (76.49 KiB) Downloaded 12 times

LR_Heikki_12-Step_Gain_Gerbers.zip: (28.31 KiB) Downloaded 9 times

LR_Heikki_23-Step_Gain_Schematic.pdf: (115.53 KiB) Downloaded 13 times

LR_Heikki_23-Step_Gain_Gerbers.zip: (39.15 KiB) Downloaded 13 times

Posted: **Tue May 20, 2025 4:47 pm**

These are the measurements of both switches in my build, with 1kHz @ +4dBu measured at the output connector in both Bypass and after trimming the output when engaged and set to position 7 (12-step) or 13 (23-step), with Threshold off. Output was connected to the input of my AD converters.

LR Heikki VariMu Gain Measurements.pdf: (90.02 KiB) Downloaded 16 times

GHR Audio

Transformerless VariMu Gain Switch PCB's

Transformerless VariMu Gain Switch PCB's

Re: Transformerless VariMu Gain Switch PCB's