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ER-301 Expander

Is there a I/O expander planned for the ER-301 ?


Would be great!

from the man himself


to be honest, I’d prefer the expander to include more inputs


Yeah, INS / OUTS would be great

I’m pretty satisfied with the large number of inputs already.

Gate and CV outputs would give unit developers a lot to work with!

One interesting idea: a knob/slider (or multiple knobs) with a LOCK button under it. If the LOCK button is pressed, the knob will instantly attach itself to the currently focused parameter. Holding the LOCK button for a few seconds would clear all attached parameters. It would be a quick way to control parameters and it would reduce the need to tie up the inputs with offset generators. Perhaps the LOCK button could have an LED next to it that would light up whenever a controlled parameter is focused.


CV outs would complete the system. There are so many cool ways to manipulate CV but no way to get the CV out, only audio.


Yeah, a gates, trigger and CV output module would be amazing. And while I’m dreaming of pie in the sky, how about a class compliant USB host? :money_mouth:


Yes to all or any of this - a class compliant USB host would be very nice indeed!!

Not trying to argue the fact that more I/O could be useful but I personally dislike expander modules - to me they ultimately feel like an afterthought that should have gone into the original design in the first place.

Yes, they typically add some important/useful functionality (the 102 is a good example) but they also add to the overall cost and more importantly they clutter things in general.

I would prefer to focus on making everything that’s already there rock solid.

I think Brian is downright amazing in the way he listens to his users but I also see this becoming a potential issue in the long run if it invites feature request after feature request - often just by one or less than a handful of users.

In the end, it just makes everything feel in constant disarray , knowing that at any time any one user could request something that yet again changes things up.

Not saying any of this is necessarily bad because I like this kind of community driven environment, where the creator is directly in touch with the user base - I’m just saying that we should probably focus on getting what’s there up and running to its fullest potential before complicating matters unnecessarily before the thing is even fully alive.


I totally agree with this statement, but I also have faith in this process and think that expanders can also be excellent and totally appropriate, the NEW Pamela’s Workout and the upcoming Xaoc Drezno, Lipsk - Leibniz subsystem are perfect examples of how a system should be separated out into a core unit and expanders.


I’m also thinking about innovative thinking within a community in general and I am a huge fan of Christopher Alexander.

It could be argued there there is nothing more potent in influencing our lives than our environments, and an example of community driven development has never been better explained than this, whether it is an urban myth or not, everyone can always get it:

In new conurbations, nowhere is paved, all the surrounding areas are grassed, as people start to live there and go about their daily lives they make the paths in the grass and this influences where the paving is laid. It doesn’t take very long and is highly effective.

It’s based around the Oregon Experiment. https://en.wikipedia.org/wiki/The_Oregon_Experiment

Reading between the lines there seems to be more than an occasional hint that Design Patterns* have been used in the development of the ER-301.

Regardless, I am fully on board with the approach Brian seems to be taking in that he has obviously established an extraordinarily robust platform that can support the comparatively straightforward development of any audio application.

This is very very cool! I think we’re in for quite a ride :smiley:


An expander for the er-301 that involves generating CV outputs would be amazing! There are already plenty of CV inputs for the er-301 so a separate expander for CV/gate inputs would be overkill imho

I was dreaming of a hybrid complex envelope follower unit that extracts separate CV from low / high frequency content and could also output gates according to velocity fluctuation sorta like a slope detector.

Also, it’s be really awesome if there was a pitch detector/analyzer that could be chained with an internal quantizer that supports scala files :}


I had a bit of a brainwave last night and I’ve just remembered again now so I will write it before I forget again, this is pure speculation, just an idea:

I thought it would be amazing if a new CV processing and output module along similar lines to the ER-301 was released at the same time as the upgrade SOM became available for the ER-301 so the ‘old’ SOM could be repurposed as the brain for the CV module!



imagine if there was a ER-401… which was exactly the same as the 301 in function, except the ABCD were all CV outputs and showed up under output assignments! maybe that mystery header on the back of the module could synchronize quicksaves/loads between a 301 and a 401. Dreamin’!


I just had a random brainstorm … is that expansion header on the back of the 301 bi-directional?

If so, something like this would be insanely awesome, and simple in operation. Taking the idea of the ADDAC manual gates, some low cost status displays, and the visual consistency of the ER universe into a simple/clean expander.

Being able to ‘tag’ up to 7 toggle, trigger or gate buttons on any unit in the ER-301 (i.e: Looper engage, Looper Punch, Tap Tempo, Reset etc). These would be immediately be listed down the rows, populated with the name of the unit or a defined name when you tag the control (IE: Lp1Punch) , with the led mirroring the current toggle on/off state (or blink for a tap tempo unit etc) … and pressing that rows button would control the corresponding tagged unit’s button, regardless of what screen the 301 is on, while also freeing up the ABCDG for more CV.

Something like this would be amazing for live use and at home in studio situations, and in my unicorn world, would be saved and recalled with quicksaves so when you load up, you’re ready to go and know exactly what’s going on! :smiley:


Oh man that could be huge

What if it was just a little wider and allowed for encoders on the other side? Or alternating gate buttons/Encoders on one side?

I love the idea of seeing what you’re adjusting - that can be tricky sometimes if you have a lot going on.

This idea is could also be interesting if instead there were gate & cv inputs with labels next to them, value indicated upon change on the screen.

The “what ifs” are definitely endless!! I was just thinking of something simple and clean using those same alpha numeric leds and status buttons that the 101 uses.

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While the design looks nice and I had a pleasant smile on the idea to incorporate CV and gate inputs into an 301-Expander I am not sure if it adds enough functionality compared with any other simple manual trigger or offset module apart from being a bit more convenient. Not that convenience is a bad thing, just not sure if it would be worth the development and how many 301 users actually would need something that makes the module wider and has no other use within the whole system as the ADDAC would have. Personally I tend to get me a monome walk which is smaller and more flexible - i just would not need so many buttons tied to the 301, I think

Maybe it’s because I am more interested in integrating the 301 into the modular system via CV then “playing” it by hand or using it as if it was a desktop sequencer/looper. I would rather like to see an output expander for CV and gate signals to have events like end of slice doing something in the system - e.g. a sequencer choosing the next slice, changing playback speed or use the 301 to generate long and complex CV curves depending on its own state and/or input voltages for feedback driven patch surveillance.

The ability to control single ER-101/2 tracks or use it as an output expander via an internal connection could be nice too.