Rossum Electro-Music Assimil8or

Now that it has been finalized and a price announced, I’ve started to take a closer look at the Rossum Electro-music Assimil8or. To my naive eyes it appears to be a perfect fit for any number of monome products, and it offers an immediacy of access that I find very appealing from a performance POV. I’m curious if any of you have had the opportunity to try it at NAMM or elsewhere, and what your thoughts are. Thanks in advance.

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bumping this out of interest. I’m mainly looking to get some percussion in my rack without having to add 8 tiptop ones. Assimil8or seems like the best option(and does way more).

Any downsides to this module?

ER-301 is similar in price and worthy of comparison, I believe.

But the ER-301 has four outputs right? This has 8 which, because I’d use it for drums, makes a big difference.

I do see your point though. It’s not as flexible as the ER-301.

You can have multiple samplers on a single track of the ER-301 and just mix their signals together to one output. You can sequence them completely independently from one another and they can play at the same time. So unless you need all the tracks independently within your modular (e.g. to process each of the 8 samples through a completely separate chain), you might not need 8 separate outputs.

So for example for drums, you could use two tracks of the ER-301 for stereo, have 8 samples on that track and mix / pan them inside the er-301 so you get a finished drum-mix straight out of the two outputs you used. And you still have two outputs left for other things.


Hmmm, that does sound very good. Thanks for sharing that piece of info!

Thanks to global chains and insanely flexible routing, in addition to onset-based slicing, you could have, I don’t know, dozens (?) of drums, potentially each individually processed (internally, using the many available DSP effects) before mixing down for the 4 outputs. The limits really boil down to CPU capacity (which is large, and eventually upgrade-able).

Mine showed up today and I tested out one of the drum kit presets (video below). I’m totally impressed with it in this capacity. It’s much more flexible than a stack of Tip top Ones would be.


For me it’s a question of how tolerant I think I am for programming. I know the answer to that question which is why I am more inclined to the Assimil8or than the 301, as the former appears more immediate in its design and implementation. Horses for courses I guess.

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Got mine yesterday. Being able to record CV is kinda amazing. The interface is mostly intuitive but every now and again I’m like What? The sound quality is right on.

I’m still in early stages but so far finding a lot more to be excited about than just drum samples which was my original reason to get it.


i’ve been debating whether i need assimil8or since i already have er-301 but the immediacy of the interface does offer something er-301 doesn’t, especially in a situation where you’d want to change samples often. took advantage of the 10% off sale at control voltage and ordered one.


Personally I find immediacy very important. I like programming things, but when I’m making music I really dislike barriers(menu’s) that block spontaneous ideas.

I’m a big fan of early Roland gear for this very reason. The 101, Juno 6/60 have thought me that magical stuff can happen when you can instantly act on an idea. One recent experience I had with this was with W/. W/ is pretty deep, but it’s accessible and fun.

I think both the ER-301 and assimil8or deserve a place in my rack.


I’m very tempted by it as well. I have the control forge and although it was daunting at first, it’s actually quite simple to program as every parameter is accessible on the interface, no menu diving.


interesting - it uses the same SOM board/processor as er-301. which means it also has i2c pins. not sure how likely it would be for rossum to support i2c in the future, but thought it’s interesting that it’s theoretically possible.


Has yours arrived? Would love to hear your impressions of it

yep, received mine, only had just enought time to rearrange my cases this weekend - can’t wait to try it, will report back once i spend some time with it.

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how’s the assimil8or @scanner_darkly? I’m on the verge of pulling the trigger

disclaimer: still learning mine and only using it in a very basic capacity right now (as a one shot sample player), so take what follows with a grain of salt.

things i like:

  • having such a straight forward layout helps a lot. which is somewhat negated by…

  • you can assign any CV inputs to any sample slots, which means you’re not limited to 3 modulation CVs per sample (you could have all 24 CVs assigned to one sample, assuming there are enough parameters to modulate…). this also allows controlling some parameters globally (and you can control attenuation per each sample slot), or you could mix&match - really nice.

  • having 2 encoders, one for coarse and one for fine adjustment is great, makes for a very quick workflow

  • when you switch between sample slots it stays on the same parameter - super useful as you can quickly adjust, say, pan position for all 8 sample slots.

things i don’t like:

  • the screen is a little busy, but this will likely improve as i get used to it

  • the folder structure / no sample preview. you can only use samples located in the current folder. when combined with no sample preview it means that you can’t organize your folders by types (kicks, hats etc) - well, you can, but if you have 100 kick samples and you just want to try different ones you have to: open the kick folder, import a sample, load it, audition, if you don’t like it you have to delete it (since you also don’t want a bunch of unused samples sitting in your folder as it doesn’t allow nesting). repeat until you find the one you like. with the samples already loaded in your folder you can just assign them and audition them that way, but for other folders it’s not a usable workflow.

  • importing from a different folder - when you open a list of folders you need to double press the load button to open a folder. if you at this point press on the encoder instead it will load that folder overwriting any unsaved changes in the process (what’s strange is that it asks you to confirm importing a sample - which is a much less destructive operation). this makes importing workflow even less usable as it’s very easy to accidentally overwrite your changes.

things i wish it had:

  • sample preview

  • envelope followers for each slot and the ability to set individual outputs to output those envelopes instead - this would be great for cross modulating samples (like doing a side chain compression, for instance)

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I’m on the fence myself. Just got paid for a buncha sound design stuff—definitely getting one of the next batch of ER-301s—havent had a chance to see what makes the assimil8or so unique aside from the generous amount of outputs and the phase modulation—which is a moot point, as I’m in the process of designing kyma patches to work with CV so i don’t really need another way to “elasticize” pitch and time…

I messed with the Morpheus over at patchwerks in seattle here, and I love the sound—but the dealbreaker for me was that it seems every “cube” resets any gain or attenuation you’ve edited on the presets back to whatever it was saved as… and the knobs are too close—not very playable :frowning:

i guess i’m worried that the assimil8or is gonna have that “one thing” that puts me off from actually loving it.

New update out today. Fixes a lot of issues:

The latest version of Assimil8or software is 1.10_181001 (released October 2, 2018 ).

Here’s what’s new:


– File lists (files in folder file browser, sample lists, and folder lists) now display in alphabetical order.

– The sample inputs can now be monitored in the Mix outputs. Set this function on the Pan/Mix screen. The left and right inputs may be set individually. Choices are:

Off : The input will not appear in the mix output.

On : The input will always appear in the mix output.

Auto : The input will appear in the mix output when sample arming is “armed” or “HOT” and will not appear in the mix output when sample arming is “unarmed” or “Safe.”

These settings are saved as part of Sampling Setup.

– Channel Solo/Mute . Channels may be individually soloed or muted. This can be accomplished in two different ways:

  1. On the Pan/Mix screen, cursor to the desired channel and select “ “ (normal), Solo (S), or Mute (m).

  2. At any time, press and hold the Pan/Mix button and press a channel button to solo that channel. Hold the Pan/Mix button and press the channel button again to return it to normal mode.

At any time, press and hold the Mutate button and press a channel button to mute that channel (Mutate, Mute, get it?). Hold the Mutate button and press the channel button again to return it to normal mode.

Solo and Mute settings are persistent across new preset selections and new folder loading.

Solo/Mute Indication – The channel number of any channel that is muted (either because it has been directly muted or because one or more other channels are soloed) is displayed in gray on the Loaded Channel Map and Selected Channel Map.

Solo/Mute Reset – Pressing Mutate + Pan/Mix together clears all solos/mutes.

Help Text – There is scrolling help text (with timeout) describing the hidden key presses, when any solo/mute parameter on the Pan/Mix page is highlighted.

Bug fixes

– Fixed a problem that could cause a display lockup during Channel Copy.

– Fixed a stereo sampling bug where the left side of a stereo pair (Master channel) was not correctly initialized as part of the pair immediately after sampling, resulting in the right side not triggering when the left side was triggered.

– Fixed a bug that resulted in improper levels of newly formed stereo pairs when editing a channel’s Mode.

– Fixed a problem where a preset set to Auto-Trigger would start before all of the preset’s samples were loaded. New behavior: presets with multiple samples wait until all samples are loaded, then Auto-Trigger.

– Fixed a problem where sample length would be shown as “0″ on Sample Info dialogs (Channels and Zones pages) for unloaded samples. The dialogs now display the correct length for unloaded samples.