# Sequential switch

Itâs also true the other way round too, Iâve been learning from @Joe for years too

I think itâ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!

Iâm kinda addicted to this I thinkâŚ

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 theyâ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 alsoâŚcertainly thereâs something uniquely elegant about the ER-301.

I may have spoken too soon re ease of understanding, Iâve been able load your quick save and after getting somewhat vertiginous navigating up and down through all the layers of the patch I now have a clue, but not much more! Iâll keep navigating and experimentingâŚit 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 whatâ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

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 âwindowingâ 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 âselectionâ under voltage control. Sequential switches would be just one application. 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 âdesign patternâ that allows the ER-301 (with its many-to-one architecture) to support ideas that seem to require units with multiple outputs.

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I think itâs this kind of property that i was speaking to in the feeling of a kind of elegance. Iâve had plenty of moments where I had thought I needed another output and then thought âOh, wow! I can just use that same output that iâve used for X for Y!â

Joe - this is great!!

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

http://www.doepfer.de/a144.htm

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Same hereâŚ 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!

âŚ 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 âbetterâ 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 itâs easier to get a very evenly divided âstepâ that tracks 1-2-3-4-repeat. Also possible with V2 by feeding a ramp, I suppose but itâ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. Hadnât really thought about it, but canât see any reason you couldnâ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.

@Joe finally found the time to read through this entire thread & watch all the videos (Iâ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?

Iâm hoping yes

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, youâve definitely understood the patch - itâ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 canât see why it wouldnât work. Let us know how it goes if you beat me to it?

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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!

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IndeedâŚ Itâs very close to this:

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Well, by popular demand, math hat ON this morning.

Hereâs an 8 step version of the sequential switch. It pretty much works the same way as the V2 4 step switch except that now you should be able to get anywhere from 2-8 switches out of it. In the short video (after of course proudly showing it off for a second), I pretty much just show how to change the number of steps that are addressed - I change it to only address 5 steps.

The quick save (shown in the video) is 8 steps with sine osc inputs, tuned to a c-major scale and driven by a saw ramp up so that it just plays the scale ascending and repeats.

Enjoy.

SeqSw8.zip (13.3 KB)

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Oh amazing[quote=âJoe, post:62, topic:607â]
Well, by popular demand, math hat ON this morning
[/quote]

OH amazing @Joe!! Thanks for doing this!

@Joe Hi Joe, Iâve finally got round to trying out the 4 and 8 step switch but I canât seem to get it to work properly. In particular for 0V the first step only is heard but for the subsequent values then all the steps 2-4 or 3-8 play i.e. they donât turn on and off with a rising saw control signal.

Iâm on running v0.2.14 - would you mind double checking from your end if the 4 or 8 switch quick save is working for you still please?