Mixers with external control

I’m wondering what’s the best way to make mixers controlled by external CV. I tried making a chain with two mixer units, each with a VCA after it, but the second VCA cuts off the first. The solution was to make a two-band unit, each band with its own mixer, but I can’t help thinking there should be a more elegant way to do this. Did I do something wrong with the mixers or VCAs in the first attempt?


  • you’d use an x-band container
  • recommend to read the wiki entry on signal flow, too…:
    When you daisy chain two units the second will affect the first one.
    Hence the second Vca is cutting your signal flow.
    However the multi band containers take signals from the left, each band is getting the same input
    But process it independently. At the end of the multi band container the bands are mixed together…
    Hope that helps…

Ah, I see you’re new in town: welcome!

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I put a VCA inside each mixer at the end of each mixer’s input chain.


Thank you for your help and for the welcome. (I am indeed new here and pretty new to the ER-301, and have been devouring Neil Parfitt’s videos.) That was my problem: my VCAs were after their respective mixer units, not within them.

Now that I can see the input levels all in one chain, this got me wondering: is there a way to see, side by side, the waveforms of each mixer’s output?

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For that see:

i often use vca’s after mixer channels when i want to break a chain, e.g.: i need some operation done inside two mixer channels but i dont want them to flow down the chain because i will tap from them via internal routing in some other part of my device. that way you can isolate a certain portion of a chain but still have it available via routing.
(i lately started doing it with offsets instead of vca after realizing they are lower in cpu consumption)


According to the CPU measurements in the wiki https://docs.google.com/spreadsheets/d/13hDQcJRfDA45yTufJo0tFy8AQ1Spit78vMehDIb3y0o/edit?usp=sharing
You’d be better off using an empty custom-source to “block” and a custom-effect for “thru”. I use semantic presets of each.


This a good point!

  • this probably speeds up the learning experience for new users
  • but then it might be good to elaborate on that a bit more here
    (Or point to a respective thread) ?
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Good call. I’m just going to ramble for a moment, but bare with me it’ll cover a use case touching this very topic (mixers and VCAs), presets, and why someone would want a “thru” :slight_smile: Maybe it saves someone time, or maybe even give someone else a chance to show me a better way to do what I’m doing or compare notes!

I’d hope that saving a unit preset would be self explanatory through the UI. Up to the user how / where to store that preset. By default the ER-301 will place you in the presets/<unit-name> folder which I think is a good place to start. Over time I found myself wanting more specific organization so I place my own presets into folders with the following structure:

  / ... etc etc drum-synths, synths, poly

The _ prefix is just so my folders show up at the top. util is where I put things like thru and block and some other nifties like fx-return-(3) which is a “boilerplate” mixer unit with 3 custom controls (1, 2, and 3). The input chain of this preset contains three mixers in series (renamed to 1, 2, and 3). Each one of those mixers contains a Linear Unipolar VCA within it (sound familiar? :wink:) whose level parameter is mapped to one of the preset’s custom controls. This is the entirety of the preset. When patching if I want to add an FX return setup on one of my chains, I can just drop this preset and place my effects directly after the three mixers (taking care to make them 100% wet) and then go into the three mixer input chains and find what I want to send, either via local routing or globals. Saves a good I don’t know, 5, 10 minutes of work? And that brings me to “thru”…

Say I have a chain with 3 mixers for drums (BD, SD, and HH) and I want to use these with my handy FX Return (3) present. I’ll drop the preset directly after those three drum mixers, and use local routing to route the BD, SD, and HH signals via the FX Return’s mixers (1, 2, and 3). When selecting the drum unit via local routing you can’t actually select the top mixer, though! This will not work because the mixer will contain a mix of it’s own input chain and everything that is coming in from the left (I mean, it’s a mixer :laughing:), but for the sends on the FX return you want a signal of each drum mixer independently, so you have to select the last unit inside the drum mixer’s input chain.

That is all fine and good, but what happens when you want to add an effect at the end of one of those drum chains? Or a limiter? Or anything? Well, if you want that to go to the FX return you’ll have to go back to the FX Return and redo the local routing. Not fun. So this is where “thru” comes in handy. If you put a Thru at the end of your chain and always make sure it’s the last unit, you can always use THAT as the local routing, and won’t have to experience this problem again.

Hopefully that all makes sense.


Thanks so much for all your thoughts and information, which I realize isn’t necessarily aimed at me at this point, but which I do hope to understand better eventually.

I’ve been able to get a visualization of four stereo mixer waveforms by going into the global chains menu and creating the mixer/VCAs there. (They don’t quite fit on the screen, so I made dummy mono copies at the end to see them all.) Now I’ve got my Voltage Block controlling the four levels, and can see all the waveforms as they’re being modulated, which is just what I wanted to do.

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