I must have an obsession with Peter Blasser’s Quantussy, the five oscillator cluster in his Cocoquantus. When Josh Rodriquez sent me five Quantussy Petal PC board, there was no doubt I would build it. I’ve written extensively about the Quantussy here on my blog. And in two recent posts I gave a redrawn schematic diagram and showed a test of the first assembled petal. One petal by itself is only an oscillator. The magic happens when five of these are interconnected (see the interconnection diagram of the forty wires, in the previous post).
Construction
The assembly is mounted between two one-foot square sheets of clear plexiglass that I had made at a local glass shop. PC boards are suspended below the top on one-inch nylon standoffs. Below, half-inch standoffs extend to the bottom side, giving plenty of support for plugging the banana jacks. The first challenge was to lay out the petals in an approximation of a pentagon. I worked up a drilling template.
LEDs in the center are soldered to the boards, and glow through the case. I added two features to my DIY version. Each petal got an LED that blinks at the rate of oscillator. These LEDs are orange in color and mounted on a CGS LED driver PC board (glad I stocked up on these years ago). The other feature is a secondary Castle output. This comes from the op amp buffering the CV from another petal that internally controls the rate. The other panel bits include a three-position toggle switch for Low, High, and Medium range.
Banana jacks:
- Green – Input for triggering the mode changes indicated by LEDs
- Blue – CV input for rate
- Yellow – secondary Castle output
- Red – primary Castle output
- Orange – triangle wave output
Wiring proceeded in two phases. The first was connecting the jacks, switches, and LED boards to their respective petal boards and then running the power wiring. (Power is supplied by a single LM7809 regulator.)
The second phase consisted of hooking the forty wires interconnecting the petals for internal cross modulation.
Demo
I made a video demo.
Oh. My.
😀
Richard, this is phenomenal!
Yes, Josh, it’s very cool! And also, thanks for including the little power regulator PC board.
Wow. Very cool indeed! 🤩
What’s the size of it, btw?
Thomas, it is 12-inches square.
Hey is there any way to get the pcb’s or the files to order ones myself? Amazing project!
Hey, great project! Could i buy the pcb’s from you? I want to build the cocoquantus system. I understand it’s formed of the quantussy and two other delay/loop modules, is there any pcb’s for this last ones??
Thanks
Hi Hugo. Josh Rodriquez made the boards and sent them to me as a gift. He has a Reverb shop where he sells some PC boards. I don’t know if he will sell this board. You can message him.
https://reverb.com/shop/crucs-gear-depot
I love this thing! What a beautiful riff on this modular flower!
Thanks, Eric. I agree this one came out well, many thanks to Peter B. and to Josh.
Hey there, Richard… long time, no text. I hope all is well in your neck of the woods.
I have a question, as I’ve been studying your DIY Quantussy off and on for many months (both, the schematic and your photographic documentation), and I think I’ve finally figured out enough to proceed with my own experiments. One thing that remains a curiosity… I don’t quite understand how you’ve interconnected CHAOS and RATE between the five boards. It appears as though one of them (board #2) is wired directly from the pots, then a second set of wires vanishes into the central void. With only a single wire attached to the remaining petals, I keep coming back to this scratching my head. Any guidance here would be greatly appreciated. This is a fantastic build, and from the fire up of your first board… wow! I certainly wanted to build one for myself. What a masochist I must be!
Hi Alan,
Each of the two pots connects to all five boards. The rate pot controls all the rates at the same time, and the chaos pot controls the depths of all five cross-modulations. Each pot wiper goes to all five boards. It doesn’t matter how they’re connected together. I put one wire from each pot to one board, and from there wires go the other four. It’s the same as if you ran five wires from each pot, one to each board.
As always, Richard… thank you for your response and guidance, it’s very much appreciated.
What you described here was the only thing that made logical sense, but I was searching for confirmation in your photo documentation and fell short with that which resides in my mind’s eye. Now, I can finish up my boards and move on to the rabbit hole of your Tetrazzi build, which I find extremely appealing and impressive. I think I’ve worked out the pot wiring for that one, but… time will tell.
Thanks again.