noise embedded.

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...

More Modulation, Please! After I got the Doepfer DIY synth up and running I immediately realized I needed more than one low frequency oscillator to modulate things. In the current setup I can modulate oscillator frequency, pulse width, filter frequency, filter resonance, another filter frequency, amplitude of the VCA etc... So one LFO simply isn't enough! The Schematic Because of my "quantity over quality" synth building philosophy I started looking for a really simple and cheap LFO circuit that I could easily multiply. I finally ended to the ASM-1 DIY synth page.  That's actually one of the pages I spent a lot of time in ten years ago when planning to build a modular synth for the first time. ASM-1 is a complete modular synth but not exactly compatible with the current Eurorack format as it uses -15V/+15V voltage. After studying the LFO schematics it turned out that the LFO is really simple. The circuit is pretty much as simple as it can get. A Schmitt tr...