As my last monotron mod is very well undocumented, i will try to keep things organized this time.
The basis for the mods will be a monotron delay.
The reason for this, besides beeing by far the noisiest because of the cheap digital delay, the monotron delay has a lot of bonuses compared to the others.
– switchable LFO waveform (rectangular or triangle)
– tunable LFO wave from slope-up to slope-down or PWM depending on LFO waveform
– delay, noisy or not its a delay
– no resonance/peak control (mod1)
– no LFO routing (mod2)
So the first mod will be to add a resonance control to it.
What you need beside very good soldering skills (we are going to tap an SMD resistor) and the usual soldering suspects, is a 10megs pot and some space in your monotron.
I solved the space problem by moving it into a bigger box:
You need to tap the original circuit at three points, and connect that to a 10 megs pot.
The FIRST point is the hardest, so if you damage that, you can forget the whole project.
I thought its better to do it in first place, then fu** everything up at the end 🙂
Make sure you dont overheat the circuit, dont melt anything and DONT use a regular 30watts iron.
You need a very fine tip and magnifying glass.
Connect this wire to the middle contact of your potentiometer.
The SECOND is easy, connect it to one of the free potentiometers contacts.
The THIRD tap is easy too, its the audio-line when entering the volume control
So what we basically did was feeding the audio back into the filter aka. resonance.
Next mod will be to feed the LFO tap-point into the filter FREQ tap-point, for filtermodulation.