Home | ER-101 | ER-102 | ER-301 | Wiki | Contact

User Replaceable CPU - THE DEFINITE THREAD - Which one? When? How? Etc


Care to clarify this statement? By “someone else”, do you mean another module maker, or a motivated user once the SDK is released?


A soft synth that interfaces with any module in a modular system is pretty great. End of the day it is all very much a modular system. Whether you realize it or not any digital module is a soft synth implementation to some degree.

I totally agree though that the 301 doesn’t need direct midi control. It has plenty of inputs and a wealth of ways to control anything the 301 can do.

But it isn’t just polyphonically over midi but MPE over midi that the SSP can do. This means you can plug your linnstrument directly into it. I don’t like this. I prefer the fh-1 as a solution because this let’s me use it with my entire system and not just one module.I don’t want to waste processing power having the SSP route CV from my controller when a dedicated module is better at it.


This means that I’m willing to provide the SDK and hardware details needed to support a DIY effort by a motivated individual (as stated in that thread).

Here “someone else” means another module maker. Providing MIDI solutions for eurorack is not part of my dream.


Fair enough. Given the hardware modifications needed to support I2C, I hope that a general purpose UART is part of the upgrade design. As interesting as potential Teletype integration is, I’d prefer to also have other avenues of expansion available.


Here is a question for everyone: How far in advance should I stop selling the ER-301 with the current board before I release a new board?


My first thought: once you get a release date for the new board, put a large disclaimer up saying there’s a new board coming.

That way you can still sell units and people can decide:

Buy current, be merry
Buy current, upgrade later
Wait for new, buy then


I thought this too.
Then the buyer can decide.
People usually (rightly so) get annoyed if they buy something and then the manufacturer announces a new and improved version shortly after, so having a notice in advance avoids this!


I guess it also depends on the cost of the upgrade.
If its not an expensive upgrade you could sell units right up to the swap over, including the disclaimer.
If its going to be expensive then i would stop sales sooner then later.
Would it be worth selling two options and have a cross over?
Will there be any cpu trade ins?
What use is the old cpu?
Could it be used for another module?

Sorry for all the questions, guess you may not have considered them all.


Personally this isn’t an issue for me, but as someone who has very strong values about the resources we all use, I am much more interested in things like recycling and or alternative uses for the old boards and would be very impressed if there were considerations made in this regard :slight_smile:


Is a new CPU board really something pressing?
It seems I yet have to push the bounderies of the er301 :scream:
(all the discussion about it makes imo the impression of a “because we can” thing)
Not saying I’m not super excited about that door! :slight_smile:


sorry if I missed something, whats the ssp?

edit: for other folks


Hell yeah!! Well, not ‘that’ pressing, but definitely something some of us would be very very grateful for as we are pushing the boundaries of what’s possible :wink:


Are there any plans for the old cpu/board? Will development going forward after the new board is out be catered to that board and it’s capabilities? Ie: will the firmware be written for both boards?

Based on the answers to these questions, I would keep selling the 301 as is up until the board is complete and is the new board on 301s. What I would do is put up a caveat on the purchase page, that there is a new board being developed and that it is fully intended to replace the board currently available. Just make sure this is highlighted and made abundantly clear and then you put that decision into the consumer’s hands.


I have mentioned this before somewhere, but what would be absolutely amazing is a little sister module for the ER-301 that was dedicated to CV duties with a full complement of CV outs - the old board could become the brain of that! :smiley:

Hey, we can dream right?


Lovely idea! But I don’t mean that Brian should now inherit the burden of developing another module just because he is updating the cpu. If somewhere down the road he helps someone else repurpose the old cpu that would be awesome.


Great idea, and if it had midi even better :wink:


Hm, I am a bit concerned now. and wonder if I should cancel my order and maybe wait for the new version - will they be compatible? Is there a point where firmware upgrades do not work anymore? Is it planned that the firmware V1.0 will run stable on the original hardware design?

I know that there is a disclamer on the site regarding the ongoing development but I thought the hardware was finished - now is it not?


Huh? I don’t understand this, the upgrade doesn’t make the current hardware any less usable.

It’s an upgrade, this is a wonderful and incredibly progressive approach to module building, other modules bake the CPU inside and can’t be upgraded, this is not something to be concerned about but to celebrate and be thankful for.

Quite in contrast to most of the rest of the technological world, hardly any computers are upgradable these days, mobile phones are verging on being throwaway devices despite the very high costs.

Feel free to make your choices, but I absolutely would not cancel on the basis that at some point in the future there may be an upgrade.


It should also be noted that the upgraded cpu is one of iteration much like Intel CPUs. Ie: same instruction set, etc. Meaning it should run the current firmware no problem. It will just do so faster and with potentially more operating memory.


Hm, telling me to be not concerned but happy and celebrate makes me feel a bit concerned.

My point is if the old version will be supported if in any case I decide not to upgrade or if everyone has to upgrade.
I am afraid that the ER-301 will feel like my iPad which is nearly unusable now with current firmware.

Also I am not sure if I got it right but the upgrade is third party upgrade, isn’t it? So is it safe that it will be physically compatible or will the whole module dedign have to change?