Holy crap. So many great responses already. Thanks to all. I will be digging into all of these and the subsequent research. More to come.

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Thanks again for all the great suggestions, thoughts, and links. A few responses:

I was thinking of getting units different than the softube emulations to have more variety, but the concept still applies. Definitely helpful in determining the functions I want.

It’s seeming that most of the suggestions are on the… er… pricier end of modular units. Something I was hoping to avoid at the outset but maybe my hopes here are unrealistic.

For sequencing, I’m leaning towards beatstep pro as it fills multiple gaps in my current set-up.

I’ll come back when things are up and running to share my results. Thanks again.

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definitely: take your time, build slow, and buy used. its possible to do a lot of fun things with a small set up :slight_smile:

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The Ian Fritz Dual AD is great and 4hp. It has a switch for gate to trigger conversion - basically to switch between AR behavior and AD behavior. Input 2 is normalled to input 1. It’s DIY but I’ve seen at least one for sale recently (I think I got mine for $60 built).

Can somebody explain why the Maths XOR logic patch seen in this video: https://youtu.be/n_1bBTPBpxg?t=137 works?

It uses channel 1 and 3 as gate inputs, and channel 2 takes the inverted OR output. The XOR can be taken from the INV output. This doesn’t make sense to me though.
My understanding is that this patch is doing something like

-(A + B - Max(A, B))

with A being channel 1, B being channel 2, and -Max(A, B) being the inverted OR output. All with a - in front since we are taking the INV output.
Since OR is always positive and we are inverting with the attenuverter, channel 2 should never affect the OR output and would only be utilized in the SUM and INV outputs.

With A high and B low it seems like it would be the equivalent of subtracting A from itself which should give us 0.

-(1 + 0 - Max(1, 0))
-(1 - 1)
0

Same for B high and A low.

Obviously I must be misunderstanding something fundamental about the whole thing :frowning:
Any guidance would be appreciated!

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I get weird results if I use CH1 and CH3 for the two gate inputs. As in, I put 8V into CH3 and I get +10.7V out of OR.

But if I use CH1 and CH4 for the two inputs:

Ch1: 0V
Ch4: 0V
OR output: 0V
INV output: 0V

Ch1: +8V
Ch4: 0V
OR output: +8V
INV output: +2.4 V

Ch1: 0V
Ch4: +8V
OR output: +8V
INV output: +2.4V

Ch1: +8V
Ch4: +8V
OR output: +8V
INV output: -5.5V

If I mult +8V into CH1 and CH2, and set CH1 fully CW and CH2 fully CCW, I get:

+8V out of CH1
-10.4V out of CH2
-2.4V out of SUM
+2.4V out of INV

So that’s the trick, I guess :slight_smile:

Thanks for doing some tests! That’s pretty weird that you are getting more out of OR than what you are putting in. Did you use dummy cables to zero out channel 2?

Also, thinking a bit more on this, an analog XOR can be implemented by doing
Max(A, B) - Min(A, B)
AKA
(A OR B) - (A AND B)

Or as is actually being done in this patch:
-[ Min(CH1, CH3) - Max(CH1, CH3) ]
which is equivalent to
-Min(CH1, CH3) + Max(CH1, CH3)
and
Max(CH1, CH3) - MIN(CH1, CH3)
and
(CH1 OR CH3) - (CH1 AND CH3)

Summing CH1 and CH3 can act as an AND gate if the low voltage is negative.

  A  +  B
  -------
 +V +V +V
 +V 0V -V
 -V 0V +V
 -V -V -V

So the Maths patch does make sense but only if you have bipolar gates. Looking at the manual for pressure points it seems that it is 0V to +8V so I’m still confused though :frowning:

The Adventure Audio Merge would be a great option for you in this kind of setup: interfaces easily with line/instrument levels (guitar pedals, external synths, etc.) including a send-return setup. Plus, it will react to incoming audio (at modular or instrument/line levels) and generate various envelopes when triggered by the incoming audio - very flexible and pretty cheap as a kit! https://www.adventurepedals.com/eurorack/merge

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I’d like to get some more use out of my wavefolder (nls buchla style). Can anyone suggest some interesting patches to try? I have most bread & butter modules.

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mult a sequencer’s gate for an oscillator, and use that gate to strike an LPG, which then plucks the wavefolder with varying CV on each note played by the oscillator that runs through it.

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Use it like an FM Aid. Take two saw triangle waves, call one the “modulator” and run it through a VCA, mix it with the “carrier” and feed the mix into the wavefolder.

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Which logic modules are people using? I have an Erica Pico Logic but I’m not so into the scrolling through logic types with button presses, and I’d like more inputs.

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I have the Ladik Bool2. The Bool3 has three inputs.

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For boolean logic, hard to top the Klavis Logica XT. It’s cheap, compact, and does loads of interesting stuff.

Do you have a link to a good explanation of logic modules?

Thanks!

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Sure. Note that there are two kinds of logic modules: ones that compare gates and ones that compare voltage levels. Some people refer to the former as digital or binary logic because everything they do pertains to creating two states (on or off), and they’re typically used to process gates and triggers, derive rhythms, and create logical patch programming (if this, then that). The latter are often called “analog logic” because they compare voltage levels (presumably one or two are fluctuating) and favor one over the other depending on which is higher or lower; these are used to process audio (or cv). Sitting between these two are comparators, which look at fluctuating voltages and generate binary states from them.

These are in no particular order—watching several of them should get you going.

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I use omiindustriies’ Illyana! https://www.omiindustriies.com/illyana
The selectable logic section is great!

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Fantastic! Thanks so much!

I have an ARC artificial neural network. It can be patced for many logic duties. Used to have the Doepfer dual logic which was also great.

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I also was not a fan of needing to page through the various functions on the Pico Logic so I ended up removing it from my case. Right now the only module I have with explicit logic functions is a Mutable Kinks which includes a Min/AND and a Max/OR in addition to a few other utility functions. That, combined with a Maths, a WMD/SSF SPO, and a VCA lets allows me to patch up any logic function I need in a particular moment:
You can use pretty much any DC coupled VCA for AND. Just patch one gate to the CV input and another to the Signal Input. You should only get a high signal out when both inputs are high.

OR can be achieved with any module that provides DC coupled mixing. Just mix the gates and then you will get a high signal when either input is high.

You can get an XOR by inverting an AND and summing it with an OR.

You can do the voltage mirroring trick to get the NOT version of any of the above functions (NAND, NOR, XNOR). Just take a gate, invert it, and add a large enough offset to get a mirrored version. You can also run a gate into channel 4 of a Maths and take the EOC output to get the NOT version of that gate.

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