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Sequential switch

I wouldn’t worry about it at all, thought you explained it very well - actually kinda blown away with how far you went to do so - I can see some serious effort went into producing that.

I thought a good follow up would be to show how to expand it to 6 or 8 steps, or reduce it to just 2 or 3 perhaps, what do you think?

Also, I guess there’s nothing stopping you putting a step (or two) on a global chain and using it to modify multiple parameters huh?

Thanks so much for providing the patch Joe (not to mention the detailed instruction) being able to work from inside out the patch makes it so much easier for me to get my head around. You, @NeilParfitt and @anon83620728 contributing hugely to my understanding of not only the ER-301 but also modular synthesis. This on top of the already outstanding work of @odevices, obviously!


Two or 3 steps is a snap. Just attenuate the CV source controlling the global step control chain a little bit more so that it never reaches 2V or 3V. respectively, and don’t bother inserting the last mixer step or two. You could also, say, use a square wave as the input to have it jump back and forth between step 1 and 4, or any other combination, respectively, for example. I may do a demo of that.

Six or 8 steps would require me to put the math hat back on… maybe after I recover from this time. :stuck_out_tongue:

Well, I hadn’t thought of that, but, I suppose not. Great idea!

Yeah, not to be demanding or anything hehe - you definitely deserve a very well earned break!!!

Perhaps best left as an exercise for a bit anyway, make folks work a bit :heart_eyes_cat:

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Yep, I have been learning a ton from @NeilParfitt. And I’ve been learning from @anon83620728 for years now!

Props to @odevices. You know, when I first got my ER-301 I looked at the Quantizer and Rational VCA and didn’t really even understand what they were supposed to do. I asked on the forum and got some answers. My initial reaction was “Oh, ok. That’s cool. I don’t suppose I’ll ever use them. Maybe they’re for someone else, but it’s cool that they’re there.”

Turns out they were the key to doing something like this. I think Brian is a visionary or something… :slight_smile:


It’s also true the other way round too, I’ve been learning from @Joe for years too :smiley:

I think it’s universally true, all this gear inherently provides a very potent learning experience and everyone you meet who is actively exploring has something to offer, even if it is just asking a question, as we see here, a simple question can inspire a whole new way of working!

I’m kinda addicted to this I think…

edit: another idea, what about placing an ADSR, or Slew, inside the step unit so the VCA opens and closes a bit slower - have I got it right, would this give a mix through effect?

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Exactly right on the circle of learning!

I am not sure it would work as expected with the Rational VCAs since they’re very much acting like a switch here -on or off. However, I guess you could put a Linear VCA after the chain of Rational VCAs and add an envelope. The only question is how do you trigger it?

This is unbelievable @Joe! I innocently started this thread not expecting such an incredible response and video(s). I have SO much to learn.
Thank you!

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Yeah, I think perhaps also…certainly there’s something uniquely elegant about the ER-301.

I may have spoken too soon re ease of understanding, I’ve been able load your quick save and after getting somewhat vertiginous navigating up and down through all the layers of the patch :blush: I now have a clue, but not much more! I’ll keep navigating and experimenting…it definitely gives me a much broader understanding of capacities and functions.

Thanks again!

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Try slowing the sine wave on the global chain way down so you can see what’s happening. Or better yet, ditch the sine wave and hook it up to an external 0-10V offset with a knob so that you can sweep it slowly back and forth across the break points and watch the VCAs.

Then adjust some of the gains, etc on the Rational VCAs. It will break it, but you can always just load the QuickSave again and restore. It might help shed some light on how/why it works.

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This is very nice work @Joe :heart_eyes:

I want to also highlight that this is exactly kind of in-depth study that gives birth to high-impact ideas. For example, if I were to distill your patch down to its barest essential component it would be a “windowing” unit that takes a bipolar input and maps it to through a window function of a given center, width, height, and maybe shape:

You would be able to use this window unit to perform “selection” under voltage control. Sequential switches would be just one application. :astonished: Fun aside: This is how mathematicians represent a selection operation in the language of mathematics, via multiplication with shifted windows!

I also want to commend the special property of your switch design that enables the outputs of each stage to be assigned anywhere in a patch. This is the “design pattern” that allows the ER-301 (with its many-to-one architecture) to support ideas that seem to require units with multiple outputs.


I think it’s this kind of property that i was speaking to in the feeling of a kind of elegance. I’ve had plenty of moments where I had thought I needed another output and then thought “Oh, wow! I can just use that same output that i’ve used for X for Y!”

Joe - this is great!! :grinning:

I would like to add that the Window Unit idea has plenty of precedents, for example:



Same here… This is what I was getting at with my first response - but as usual @odevices put it much better than I did - it really is superb!!

+1 for a Window unit!

… and another reminder of the GoF book - it really is one of the very, very few books I kept from the MSc Computer Science course and is highly recommended reading!

V2 amazing work! Thanks so much for sharing @Joe

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I was reflecting a bit after building these. When building V2, I really thought it was a “better” approach since it added the ability to track to any CV source. But V1 has some pretty interesting things too. For example, with the first approach it’s easier to get a very evenly divided “step” that tracks 1-2-3-4-repeat. Also possible with V2 by feeding a ramp, I suppose but it’s a little fussier to condition the signal.

With V1 you can also control the pulse width and have some moments where none of the switch steps are passing signal. Hadn’t really thought about it, but can’t see any reason you couldn’t increase the duty cycle of the input to more than 25% and overlap them. So depending on the application, they both have some interesting properties to exploit.

I’ve been thinking about this and it’s starting to blow my mind… :slight_smile:

@Joe finally found the time to read through this entire thread & watch all the videos (I’m actually sat on a train from London to Leeds to attend the Leeds modular meet this weekend so really nice to get the time to concentrate on the concepts and uses) and I have to take my hat off to you and say that this is next level stuff!! And the effort in sharing & description is VERY much appreciated!!

So my initial thought is to use the V2 switch approach for complex sample FX processing where I input the same sample player (maybe in a global chain or use @NeilParfitt idea of a custom unit with a top control that has a sample player feeding the 4 mixers) into each mixer unit and then have totally different FX processing (filter, delay, limiting etc) to really transform a previously static sample.

I have a question with the above in mind (using V2 of the patch):

So in your examples you are often using a sine wave in the global chain to drive the patch - for clarity is it the voltage of the Sine wave at a particular time that determines which mixer is active?
Assuming I understood the patch and the answer is yes then I could send a CV sequence into the ER301 instead of a Sine & sequence which mixer I wanted activated?

I’m hoping yes :smiley_cat:

This could really open open some really interesting ways to give some of my existing live material an added dimension especially if I use the ER101/102 as the sequencer to select the mixer!

Thanks again!!

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Thanks for the compliments! Yes, you’ve definitely understood the patch - it’s the voltage at a particular point in time determining which mixer is active. I used a sine wave for simplicity of illustration. It really should work with any internal or external CV driving the global chain. I have not actually tested it with a step sequencer yet, but can’t see why it wouldn’t work. Let us know how it goes if you beat me to it? :slight_smile:

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Great stuff!!

I think the fact I was able to follow your patch away from my modular is a testament to your videos & descriptions!

Thanks! :+1:

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