CMOS VCO Introduction. The circuit presented here is aimed towards simplicity and ease of construction. It can be an addition to a modular system, used in a standalone fashion or as a test oscillator for your bench. I found it interesting to use the gates of …

With the 4069 VCO this is really simple and this is partially why i like it as much as i do. Allmost all VCOs can be split up to a few basic building blocks, nameley a CV-summer, a exponential converter, the core and optional waveshapers. Let's take …

2020年12月10日 · VCO's are hard and I'm new at this. I've found the Rene Schmitz 4069 to be a cheap model system. It's a schmitt trigger and inverter, flipping an integrator cap; so we get a sawtooth by pushing constant (calibrated) current into the system. It was modified and made into a video walkthrough by Moritz Klein. Very helpful for newbies.

2021年4月2日 · Hey guys, I've been messing around with the 4069 vco circuit by rene schimdtz and i managed to make it work. I would like to know what you guys think, have build this one yet? And how was your 1v/oct tracking? I managed to tune it for 4 5ish octaves so far, any suggestion on improving it is welcomed thanks!

If you hold the modulation inputs at all times (with voltage follower opamp outputs) you will not have an issue. But if you have a switch going to an input that selects (lets say) a VCO, and LFO, and nothing (center off) you will have to re-tune as you switch on/off.

2021年2月9日 · I made that same module a couple years ago, it was my first VCO too. I ended up putting thermal paste between the flat faces of the exponential converter transistors, and zip tying them togethere, and I can generally get about 3 octaves of acceptable linearity out of it (although I haven't messed with it in a while).

2018年11月22日 · This 4069 VCO with diode charge is far away from a perfect sawtooth VCO core. I bet if you treat your prototype with a heat gun or put it in an oven for a 40° temperature drift "test", you will not be able to see a difference between using a TL07x or a LTC2058.

2009年8月29日 · Last night I completed my built of the 4069 vco and the vca-2 by René Schmitz . It was a rewarding experience to play a self-soldered circuit that can put out real melodies once i debugged my chaotic perfboard

2019年3月12日 · I've put together Rene Schmitz's 4069 VCO (see https://www.schmitzbits.de/vco4069.html); I've added the "Sawtooth buffering amplifier" portion as well. Basically, the sawtooth wave has a discontinuity corresponding to the falling edge of the square wave; adjusting the duty cycle of of the square shifts the phase of discontinuity as well.

You've found a project where we take one really cheap microchip, a CD4069 (nice), and stick some parts to it, and get a very useful pitch-tracking voltage controlled oscillator! The version we will build only has a saw or ramp waveform, which is …