Diy LFO in LZX standard

Hi LZX-hivemind!
Im slowly expanding my modest video synth system and Im in dire need of LFOs so I took it upon myself to build some. I found this design by Kassutronics and have made an attempt to modify it to work smooth with the LZX standard.
Im kind of a circuit design noob but I got this to work in Falstad!

Link to my Falstad build here:

What are your thoughts? Can I get away with fewer op amps? Will it smoke and burn? Will something else smoke and burn?

Kassutronic one here!


Looks nice!

I wouldn’t worry much about avoiding opamps as a way to lower circuit complexity, personally. Just implement this with 2x TL074, and use that 8th opamp for an inverted output or something else fun.


Ha! I was thinking of doing similar with that Kassutronic LFO design too! But I got sidetracked after I started it by another project, and I’m several beers deep tonight, so I’m not much help. But I say go ahead and breadboard it. Op amps are cheap – you don’t need pricey video-rate op amps unless you’re looking to get into video VCO territory.


Ok update! Of course I should build a double LFO because why not! And one should obviously be sinewave! Here is my take on that:

Im calling it: LFO or GTFO


I like this project, I have played with the Kassutronics/ken stone version on breadboard for my audio rig. Sorry if I am pointing out the obvious but I have 2 comments, a bipolar LED follower is always a nice addition to an LFO and you can see how Kassutronics did it.

Also there is no power decoupling and no power input. Take a look at the LZX Github page (link below) and you can get access to the cadet schematics. Each IC needs 2x 100n capacitors, one on each power rail as close as possible to the power input pins (pins 4 and 11 on a TL074). For power input you need a 2x8 connector, 2 diodes, 2 ferrite beads and 2 10u electrolytic capacitors. These will give you some noise suppression, reverse polarity protection and a little voltage buffer on the power supply to reduce the chance of supply voltage drop.

If you haven’t seen it, here are the Cadet RGB Encoder schematics on Github.