I just watch this video, and I found it interesting and simple
DIY SYNTH VCO Part 1: How to build an analog oscillator core from scratch
In this series, I’m taking a detailed look at how to build an analog VCO from scratch, using just a handful of cheap components. It’s the basis for any synthesizer. To keep it as beginner-friendly as possible, I’m explaining what all the components do in detail.
This first part deals with the oscillator core, op amp-buffers, AC coupling and voltage dividers. If you want to follow along, here’s a bill of materials:
1x Breadboard 2x 9V battery plus clip OR 1x dual 9-15V power supply 1x 40106 IC 1x TL074 IC (you can also use a TL072, we won’t be needing more than one op amp) 1x 1N1418 diode 1x 1 uF foil capacitor 1x 2.2 nF foil capacitor 4x 100k resistor 1x 3.5mm OR 6.35mm jack socket lots of jumper wires
The Korg sequencer shown next to it outputs either V/Octave or V/Hz scaling, according to the control panel. Since the latter is much easier to implement I’d guess that’s what this simple circuit does.
Right, exactly. There’s a version you can do with the 4069 and two transistors glued together on that Hackaday series, but I was surprised to see the op-amp on the 40106.
30 seconds in he says “… with reasonably accurate volt/octave tracking…”
My guess would be the diode gives the exponential conversion.
Edit after listening to it, that’s not what the diode is used for. The initial screen shows two transistors.
Some good techniques there. I learned a lot from that video.
It surprised me though that he assembled the whole module before testing. I would want to test more during assembly, if only to save the extra work of disassembling in order to diagnose problems. It’s much easier to test a circuit on the workbench. But maybe he’s become confident and doesn’t normally need to worry.
DIY SYNTH PSU: How to build a simple dual power supply
Nothing more to say, still super super clear and if I had seen this video earlier I would have better understood some things that were really not clear at the time.
Nice! Love this guys content. Hoping to build the triple VCO he builds at the end of the VCO series soon.
Does anyone here support him on patreon? If so, do you think it’s worth it? I know it’s only £6 a month or something but money is tight for me at the moment!
