MUX TREM – A Multiplexer Tremolo!
This is a Pattern Tremolo that creates its step-patterns in a pretty unique way: Binary Address Multiplexing.
Yeah, that’s right… Science, baby!
It’s not perfect, bit of a work-in-progress really, but it’s pretty fun and perfectly useable, and seeing as people are downloading it already I might as well explain what the hell is going on!
Q: Alright, so “multiplexing”, what is even that?
A: Ok, a multiplexer (or mux) is an analog switch that selects between several inputs and sends it to one output, based upon its ‘selector inputs’. In ZOIA that’s basically just a ‘CV In Switch’, where the Channel button is the ‘input selector’.
Q: Okay, so like a ‘data selector’ then?
A: Yep, exactly like that! This thing has 4 ‘steps’ to select from (so a 4-way mux switch), and cycles through them in interesting patterns.
Q: Fine, but then how do you make it Tremolo?
A: The MUX output controls VCA levels, so you can chop out cerain steps by turning each of the 4 steps on/off on PAGE0 (in Blue), smack in the middle of the page!
The Depth of the Tremolo, or ‘choppiness’, is set with a Red CV Value, I think on PAGE1.
(You could also set the max level of individual steps somewhere on PAGE1 I think..)
Q: Gotcha, steps are on or off.. But what determines the pattern then?
A: Here the fun starts! There’s a Master LFO on PAGE0 (in Green) to set overall speed, that goes into a bunch of Clock Dividers with different subdivisions. The three On/Off pushbuttons (in Blue) on the left and right side of PAGE0 determine which clock signals are sent to the ‘input selector’ of the mux.
Q: So this is that ‘binary addressing’ you mentioned?
A: Yes! The LEFT side has a ~50% connection strength with the Input Selector, the RIGHT side has a connection strength of ~25%. This effectively makes them Binary input selectors, where LEFT is the highest bit, and RIGHT the lowest. Here’s the truth table:
[LEFT – RIGHT] = [STEP]
[0 – 0] = 
[0 – 1] = 
[1 – 0] = 
[1 – 1] = 
Q: Sounds complicated, why not just cycle through the steps with a Sequencer?
A: With a sequencer, steps always go in the same order (1-2-3-4), but THIS way you can make longer, cooler and uneven patterns (like 1-2-3-4-3-4-3-4, or 1-2-1-2-3-3-4-4).
Q: I’m lost…
A: Nevermind, just push only ONE of the pushbuttons! So, the LEFT side pushbuttons determine the UP-DOWN motion of the pattern. Push only 1 and it should go steadily up, then down, and repeat. If you ADD one more button, another clock is added, they go through a boolean OR-gate, so the up-down pattern changes.
Q: Please stop… my brain… I can’t even..
A: Same thing for the RIGHT side, which determines the pattern in LEFT-RIGHT direction. Because each pushbutton is a binary selector, each buttons basically doubles the nr of patterns.. and there’s 6(!) of them, so you have 64 cycling patterns in this thing!
A: And that’s JUST the cycling order of steps, so with the permutations of turning off individual steps you have LOADS of patterns to create!
Q: …I’m scared…
A: It’s also in stereo, so by pressing the LEFT STOMP, you go into PANNIG mode, where it’s not a hard Tremolo Chop, but instead a hard Pan from left to right!
Q: [*dialling 911*]
A: Finally, the Red stomps in the outer corners invert certain things in X- or Y- direction: The top 2 flip the step-pattern, the bottom 2 flip the panning in either direction.. Yeah, now I remember why I was hesitant to write an explanation…
Just go and try it out! Hope it’s fun, maybe I’ll improve it in the future (once Clock Dividers, which are used EXTENSIVELY here, are not so buggy as they are now…), maybe people get inspired by this, and hopefully come up with other cool alternatives to create patterns!
P.S. Maybe the gain of super low, just find the Output stage and correct.