DIY Synth (electronic video for beginners) - Moritz Klein

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


That’ s a familiar voice, I thought when watching the video. This is from the arpeggiator guy!

Yep, really worthwhile to keep an eye on his channel.


I can’t watch it right now but I’m curious-is it a 1V/Oct oscillator or not?

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With that BOM, I’d be *very* surprised if it was :slight_smile:


it’s only the part one but i don’t think so, it seem difficult with a CD40106

but it’s the real simplest osc


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.

Edit: I was wrong. See below.

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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.


DIY SYNTH VCO Part 2: How to control an oscillator with a voltage


DIY SYNTH VCO Part 3: Temperature dependence & scaling


DIY SYNTH VCO Part 4: Waveshaping & More


Thank you, this was an excellent set of videos. He’s super good at explaining stuff and probably better than most teachers at explaining the concepts.


How to build a DIY 3X VCO module from scratch

“In this final episode, we’re putting all the theoretical knowledge we’ve gained in the past 4 episodes to work and build a proper triple VCO module.”

… Kosmo panel ! :grin:


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.


The following of this series :

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!

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The continuation of these excellent videos !!!

DIY SYNTH VCF Part 1: Analog filtering basics :


DIY SYNTH VCF Part 2: Active Filters & Resonance

allways simple and excellent !


DIY SYNTH Quick Tip: Sawtooth-to-Triangle Converter


The continuation of this excellent series!

DIY SYNTH VCF Part 3: Resonant High-Pass & Vactrol-Based Voltage Control :