noise embedded.

Midi Moose. Midi Issues Everywhere After finalizing the Acid Moose 303 clone build my midi usage increased significantly. So did my midi problems. Unfortunately I just couldn't get the Acid Moose midi interface working reliably. Sending too many messages made it freeze and the whole device had to be rebooted. I tried changing opto-isolators, crystals, pretty much everything around the pic microcontroller but nothing helped. Anything more than simple note on and note off messages would make it fail. Unfortunately that midi implementation is significant part of the sound because it mimics many 303 peculiarities so changing to another microcontroller implementation wasn't an option either. Needless to say the source code is not available. I finally gave up debugging it and decided to add a midi filter in front of it to throw out everything except the bare minumum of needed midi note messages. Around the same time I also bought an Elektron Digitakt sequencer/sampler. ...

The Very Beginning of the Signal Chain Voltage controller oscillators, or VCO's, are the root of everything in subtractive synthesis. That's the place where the sound is born and everything after that is just modifying it. VCO really creates the sound. It is also the component that defines pitch and thus makes melody and harmony possible. Rest of the signal path is mostly about timbre. (And rhythm of course.) I started my modular synth by building a Doeper DIY Synth so I only had one VCO. It really limited things so I had to get more. Things got a bit better when I added another Doepfer DIY Synth to the rack but 2 oscillators is still not that much. There's two reasons to add more oscillators. First one is to be able to play multiple notes at the same time to generate harmony. The second one is to configure multiple oscillators to play the same note to generate more complex sounds. Analog VCO's are always more or less out of tune so the sound will get thick...

Let There be Noise! The blog has "noise" in it's name so it's about time to write a post about noise! After finishing the 4xLFO module I started looking for another simple but useful module to build. After studying the ASM-1 schematics  it was somewhat obvious that  the noise module  would be my next project. It's almost as simple as the LFO and significantly widens the sonic possibilities of my synth. I only have 8hp wide blank front panels so a noise circuit alone felt like waste of panel surface. Of course the obvious companion for a noise module is sample and hold. By feeding white noise to sample and hold you get randomly changing control voltage. Feed that into the CV input of your oscillator and you get the classic "computer speaking" sound from the past. White Noise White Noise? Pink Noise? Most common noise types in synthesizers are white noise and pink noise.  White noise  contains equal amount of all frequencies and sounds a...