Made a smaller (and cheaper) variant of the midi-Stim circuit

DIY
21

Updated the circuit, moved the filter capaciter to the low voltage side.
The filter capacitor could be omitted if your amp has built-in filters.
RC filter with 3.9 Ohm and 2 uF has a cutoff frequency around 20 kHz.
circuit v2

Didn’t have the right capacitors in stock (part of the reason I put them on the output side), so waiting for parts…

22

That’s the cutoff frequency without load. Concerning the lowpass, the source resistor and load impedance act as in parallel, so the cutoff frequency will be a bit higher.