Simulation (Falstad, etc..)

Hey all,

I have been doing/drawing some Falstad simulation of few circuits I wanted to understand a bit better.

(NB: these design are not mine, I just recreated some of them using Falstad)

I thought it could be useful for others to put them all somewhere (I couldn’t find a similar kind of topic) so anyone could have a play with it or use it as a starting point for designing something different.

808 Kick (taken from @EddyBergman webpage: Eddy Synthesizer Build part-46: 808 KICK for EURORACK. (Juanito Moore circuit).)

MS-20 style VCF filter (LM13700 OTA)

40106 type VCO (based on @moritzklein design)

BitCrusher (J113 style)

VCF Diode ladder style Resonant Folding


Steiner-Parker VCF

I’ll update the list when I’ll have some more.



I added Falstad simulations to quite a few of the articles on my website. Here are a few:

Thomas Henry VCO555 by Fabian Kempe

The Gristleizer

YuSynth 555 LFO with Sync


This is great work! Soo cool.

1 Like

Here’s a simulation of the Baby 8 sequencer on my website. Ignore the End of Cycle trigger output. In the simulation it doesn’t work.
8 step sequencer simulation


A good simulator for mobile devices

1 Like

It seems there’s a successor to LTSpice under development:

Which is good news. Less good is that it, like LTSpice, is Windows only. Maybe, like LTSpice, it’ll run under WINE. But I’d just as soon not attempt to do that until and unless I hear someone more WINE-savvy than I has done it.


Has anyone tried micro-cap? Apparently it’s free now & was recommended as an option in a YouTube video on Qspice

Windows only, apparently, and no longer developed or maintained; the website is said to have been taken down though is archived at