Introduction

I'm Ryan Kojima and I'm running a tiny guitar pedal company, Nunomo LLC. I love music and have a passion to find new ideas in this industry. I'd like to make unique products always (Not copy pedals!).

During some experimental projects, I tried to detect pitch of the guitar tone. I couldn't reach enough accuracy because of unstable waveshape of the guitar (That was similar to ESP in Korg MS-20. That's fun for experimental things but unstable). I thought I may need to go 100% digital FFT + wave pitch detection algorithm and it was not interesting idea for me (Using A/D converter makes me the feeling I'm making software product), so I threw out the idea few months ago.

After that, I noticed I can get excellent accuracy and acceptable latency when I limit waveshape to simple one like Sine, Rectangle or Sawtooth, then I found this could use as alternative control interface of Analog synthesizers. Fortunately I have one analog synth (Moog Werkstatt), so I started to polish this idea.

Currently It's just a prototype circuit but I want to make this as Eurorack module. In order to make it, I need funds to make PCB and other parts. Please help me to create another way to control modular synth!

How it works

Audio controlled sequencer listens incoming audio and detects the pitch of the signal. That mean you need another synth or soft synth just for control. Input signal has to be simple shape like Sine, Saw or Rectangle. Attack immediately, no decay, 100% sustain, no release time. Most of synthesizer or soft synthesizer has a capability to generate those simple sounds. I tested some soft synths and most of them worked. Some Synthesizers cannot take off some effect completely(e.g. reverb or chorus), in this case, You may need another synthesizer.

If you send audio signal to the module, then you will get following signals.

• Pitch (1V / Oct)
• Pulse Width
• Gate (On / Off)
• Envelope (Generated from Pitch and Gate information)

Probably most of them already have a envelope generator but this module also has Envelope Generator, in case you need another one.

Accuracy & sound? Please check the videos!

As you see, pitch information is completely free from ABCDEFG notes. If input signal pitch moves, then pitch CV moves. If you glide, output will glide. You can even try LFO. Also you can use PW information to control any another parameter.

Here is current sketch of Euro rack module (9HP).

Risks & Challenges

• There is only little challenge in order to convert this to Euro rack module.
• I need numbers to order PCB board and front panel.