The Multipus is a different distortion pedal.
I grew up playing jazz guitar. I was always so jealous of the horn players. Sustain was not an issue for them. As long as they could blow, their notes could ring. This is not the case with a clean guitar. As a result guitar players have turned to overdrive and distortion for compression and sustain. Throughout the years I’ve played many distortion pedals looking for a sound. Some pedals got me some of what I wanted some of the time, but I could never quite get what I wanted.
I wanted to preserve the clean attack of my instrument and make the notes sustain in a natural way. Many pedals squash the attack. Often the drive sounds fizzy or harsh as it clips. I could get sustain, but most of the time the tone of my guitar was severely distorted as well. It is a distortion pedal after all.
Over the years I tried things like playing with two amps — one had heavy distortion on it and one was clean. This was cool sometimes, but carrying around two amps was a pain and it was hard to dial in.
After some years playing around with tube amp circuits and other analog pedal circuits i had an idea: What if i could make a pedal with dual signal paths that mixes together a clean sound and a distorted sound.
Using three op amps, The first multipus was born on a breadborad. After some fine tuning i was quickly excited by the results.
The pedal buffers and splits the signal at the input. One path is a warm and transparent full bandwidth clean boost. The other path is a heavily clipped and saturated distortion circuit. I employed a second order active low pass filter to remove high frequency fizz and I also employed asymmetrical variable clipping. The headroom control adjusts the ceiling of the clipping which ultimately controls squashing and the dynamic range of the distortion circuit.
Both signals are mixed together at the buffered output with the blend control.
The pedal can produce a fully clean boosted signal, an extremely distorted wall of sound — and everything in between. Endless sustain can be generated underneath a crystal clear attack.
The pedal does not filter out low frequencies like many drive pedals do so it can also be used on bass to good effect.
If even more clean headroom is desired all components are high quality and rated to at least 25V so a higher voltage supply can be used. I recommend a maximum of 18V.
After making several of these pedals completely by hand I designed and had fabricated a 2 layer PCB that because of it’s design with ground pours sounds fantastic and is very quiet even at maximum settings.
An internal trimmer controls the level of the clean boost. This is helpful to precisely calibrate the quality of the clean boost to match with your guitar’s output.