Hero VCO module

Here we have the Hero voltage controlled oscillator in Kosmo format. This is my idea of a nice 3340 based VCO, combining features I like from several previous designs. It has fixes for the 3340's most problematic attributes: there's no frequency shift when pulse rate changes and no ringing on the pulse wave falling edges. Amplitudes are a uniform ±5 V for all waveforms — which include sine in addition to triangle, ramp, and pulse. There's a ridiculous but nice 11 position octave switch. But what's that extra pin header for? NOTE! If you want to build one of these, at the moment there are just a few board and panel sets available on my Tindie store (along with some other nice modules, check them out): https://www.tindie.com/stores/analogoutput/ 00:00 Intro 00:10 Hero VCO 00:55 3340 chip 01:56 Front panel tour 05:21 Under the hood 06:00 Pulse width frequency shift and negative voltage supply 09:24 Pulse wave ringing 10:12 Output amplitudes 12:33 Demo on scope 15:18 Sound demo 17:53 Wrapup and teaser Panel design files, Gerbers, and documentation in GitHub repository at https://github.com/holmesrichards/herovco Sidekick VCO video: https://www.youtube.com/watch?v=8hrPeu4r8-k Blog post: https://analogoutputblog.wordpress.com/2022/06/20/hero-and-sidekick/ Music: Ringtone by Rich Holmes