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...