ER301 as an end of chain mixer/effects hub

Hello guys,

Future owner here, i wanted to ask if the ER301’s lower inputs can be used for audio? What would be the difference between those and the upper inputs?

And how feasible is it to route audio in such a way that the module can serve as a mixer with effects per input?

In short: yes all inputs (except the four gate ins) work with audio. For more detailed information see ER-301/Front Panel - O|D Wiki


you’ll get an amazingly flexible routing system, i.e. also a flexible mixer with internal and/or external
aux buses. there are several threads and tutorials that deal with some of the use cases, just search
for your key words in the forum…
when you get your er301 at your hands and have a specific use case just ask away!


Thank you! I have perhaps another question. Is it more financially feasible to wait for the future processor upgrade before purchasing? How soon might that happen if at all?

generally, you’ll find your answers here:

personally, i can’t imagine how waiting for a cpu upgrade would be better financially.
if and when the upgrade comes, the cpu-upgrade will probably be just a tiny fraction
of the value of the whole module.
note that a replacement board for the current cpu is just shy below 40 €

if the industry is still trying to maintain the truth value of moore’s law,
then i guess an upgrade cpu board won’t be able to empty your bank account :credit_card:

@Joe’s sunglasses just reminded me of this one:


I can see what you mean. Viewing the thread and seeing Brian’s comments on the subject, maybe a more important factor is that it will take a very long time until the new board will be produced. The price, however low (and it will obviously be more than 40 euros lol), will still be a factor in the decision to wait or not.

i think that your choice must be based on what the 301 can actually do, in the present, for you, because in the end you don’t know how much power will be added by the upgraded board. in my case i can tell you it is already an incredibly powerful module as it is, so whatever the benefits will be in the upgrade it will feel more like a bonus than a much desired goal for me :slight_smile:


@hyena Agreed. Also the more time you spend with the module the more ways you find of achieving things efficiently. I hope to see (and make) more things built in the middle layer as you can save a decent amount of CPU power compared to the UI layer by removing unwanted unit elements, hard wiring internal connections and so on.

I’m looking into this as well. I want to use channel 1 to send out to and external FX unit and return stereo in input 1 & 2. I want to use channel 3 & 4 for stereo synths and samples and being able to send out a part of the signal to output 1. But I have only got limited success so far. Should I make a Global unit for each synth and sampler or is there another way?

The main thing to remember is that outputs are hard-coded to a channel. Out 1 will output whatever is in channel 1. The inputs are a lot more flexible and can be dropped anywhere inside of a chain, and can even be virtual (e.g. output 1 can be an input somewhere in channel 3).

So in your example lets assume CH 3 & 4 are going to be your stereo output to your sound card or speakers. Set them up as a stereo pair by pressing both channel buttons simultaneously.

Drop a mono mix unit into CH 3/4 chain. In it’s subchain, assign the input to OUT1. This mixer will be your dry mix for CH 1. If you have a wet/dry control on your external FX and want to use that you could optionally skip this step.

Route a cable from OUT1 to your external FX. Route 2 cables from your external FX to IN 1 and IN 2. Drop a Stereo Mix unit into CH 3/4. In that mixer’s subchain, set the inputs to IN 1 and IN 2. This mixer will be your wet level for whatever is generated on CH 1.

Here’s where it starts to get a bit murky for me. It sounds like your external effects are mono in stereo out. Are you just looking to send one side of these (left or right) to the external effects?

You could add additional mixers in the CH 3/4 chain after the two we just added above and put stereo sampler/synth units in them. You won’t be able to route those to CH 1, though. (Technically you could put a mixer on CH 1 and set its input to OUT 3 or OUT 4, but you’ll be creating a feedback loop since CH 1 is already in CH 3/4). So if you need to route these synths/samplers to CH 1 for external processing, you’ll want global chains which you can then use as inputs to mixers on CH 1. I’m not sure you’ll be able to pick one side of a stereo global chain to assign into a mono mixer on mono CH 1 though.

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Thank you Joe. That’s exactly what I’m doing right now but it’s not exactly perfect. My external effects are mono in stereo out and ideally I want to be able to use out 1 for effect 1 and return it to the ER301 on input 1&2. Out 2 of the ER301 will be send external effect 2 with the return channels coming in on ER301 inputs 3&4.

I want to be able to use various synths in the ER301 and Sample players each within their own channelmixer and being able to send to effect 1 and/or 2. The dry signals will be on Channel 3&4 and I’ll make two additional channelmixers for the both effects returns on 3&4 with the full wet mix.

The only way I think I can do this is that all my synths and sampleplayers are as custom units so I can use them in another channel mixer on each channel to be able to send to the effects are not.

It’s very complex for actually a simple routing. If the outputs were not hard linked to each channel and free assignable it would be easier. We could even make a send/return unit using internal or external routings.

What do you think?

If I’m reading you right, I don’t think custom units will really help you. The problem is you’re out of channel chains.

CH 1 & 2 are dedicated to being mono FX send busses.
CH 3/4 is dedicated to being your stereo main

So it sounds like your set up needs global chains to house your synths and samplers.

You want their dry (stereo) signal on CH 3/4, and then you want to sum them to mono to put in a mixer on CH 1 or 2 to send to external FX. Is that right?

I’m not sure if that can be done. Not in front my 301 at the moment but I’ll have a look when I can…

CH 1 & 2 are dedicated to being mono FX send busses.
CH 3/4 is dedicated to being your stereo main
Yes, exactly.

So it sounds like your set up needs global chains to house your synths and samplers.

You want their dry (stereo) signal on CH 3/4, and then you want to sum them to mono to put in a mixer on CH 1 or 2 to send to external FX. Is that right?
Yes again, but I still need to test this as well :wink:

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The only thing I’m not sure about is summing a global stereo chain to mono. The rest I’m pretty certain is no problem.

  • i usually put the inputs also to global channels,
    so i can mix the (stereo-)returns (@ins 1-4) from the aux-buses to the main out pair, too.
  • since i prefer prefader aux-sends i put respective mixers on the
    main chain (in your case 3/4): mixers for all dry signals coming from
    global chains and also mixers for the aux returns (via ins1-4 in global chains) from the external FX (which i set fully wet to avoid phase cancellation/addition)
  • i recommend putting limiters at the end of all global chains, as well
    as at different places in the mixers on the main channel(3/4)
  • 16n faderbank and derivatives will give you plenty of faders so you can mix
    dry signals and fx sends (via vcas on dry-mix-, wet-return-mix-channels on main and/or send channels (1&2))