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


Sorry, but you have completely the wrong idea, reverse everything you just said and you will be on the right lines :smiley:

Enough said I think, don’t think there’s anything more to be said. If you have concerns beyond this then I would advise contacting O|D directly to discuss.


I don’t understand why you are discouraging the discussion again?

This is the OID forum, isn’t it? Is it only set up be happy and celebrate the Lord? I don’t want to get into an argument that I don’t understand again.

I am about to receive a device I payed a lot of money for and the way you are handling my concerns if it will be outdated soon / before the development is finished is very irritating to me.

I just asked a viable question.


And we answered it… what’s not to understand?

The module is designed to have a SOM to avoid the exact problem you are concerned about.

The reason I advised you to contact O|D is because you are just saying the same thing over and over and not reading what is being said to allay your concerns. It’s at this point discussions derail and folk get the wrong idea, it’s not helping move the discussion forward it’s just reiterating the same non-existent problem.

Does this help?


I may be speaking out of turn and my memory may not always serve me perfectly, but I think I remember Brian mentioning that this CPU upgrade would be just that: a drop in pin-to-pin upgrade that would not render the rest of the ER-301 redundant. The upgrade is meant to give us more headroom for processing complex chains and units.

Over the course of the previous year some of us have gone through probably 50-70 firmware upgrades and Brian has been incredibly vigilant on squashing bugs while simultaneously bringing greater functionality. To try foisting onto his shoulders that he might might build in a kind of planned obsolescence feels harsh and would make this seemingly legit developer/inventor appear to be a nefarious character taking a page from one of the worlds richest public company’s that must have quarterly results above all else.

Over the years that Brian has been developing O|D as a company it looks to me like he’s a person that goes the extra 20 miles and support his products with a kind of customer support that’s unapproachable and intended to do no-harm.

[As I’m writing this I see a new comment appear and I can’t help but wonder if Tbecker isn’t here on this thread with us?]


Exactly… I think this is a stroke of genius and flies on the face of exactly the kind of wasteful limited lifespan profit driven product design that so many devices are plagued with in our capitalist world!

To address the wholly erroneous correlation; the iPad is the precise opposite of the ER-301 in this regard.


I don’t believe that anyone who speaks favorably about Brian’s efforts is trying to loft him into a Christ like figure that deserves your condescending stab at Kel that there’s some kind of Church of O|D, it’s about showing respect by some of the more creative people here in understanding that Brian’s openness and effort is typically unseen by ANY manufacturer/creator.

Some of us would like to help protect that relationship as we certainly cherish this unique situation. While nobody is trying to shut down conversation and questioning, some of us would like to ask fellow forum participants for civility. When we see, read, or understand an underlying hostility maybe we are personalizing something that Brian has thick enough skin to easily deal with and that we are projecting ourselves into his role (not the smartest thing to do I know), but your tone and what I’ve read of your conversation here and on llllllll.co has seemed unnecessarily aggressive.


No, I don’t think that answered my question and I dont understand the unnecessary hostility.

What I take out of your iPad analogy is that I have to upgrade the hardware next year if I want to follow the firmware development. Is this correct?

On a sidenote: I cannot see how a concerned question derails a thread more than the ongoing eurorack-typical take-my-money-two-of-them-is-better-than-one consumerism does. At least answering concerens with celebration is not the exact opposite of an iPad/Apple.

I never questioned the capabilities of Brian.


:cowboy_hat_face: mod hat on

Okay, and I am saying this to myself as a member of the community as well so absolutely not picking on anyone… that’s probably enough, lets not let the conversation drift any further.

Keep it civil and on topic please!

:slight_smile: mod hat off


No… completely and utterly wrong!


The hostility is your perception as I don’t believe there was any. Because I want you to be properly informed I’m going to assume based on your username that you’re German, and with that I’ll explain things in German:

Wenn du sagst: Ich habe schon über 800 Euro ausgegeben und jetzt muss ich noch mehr bezahlen, damit ich den neuen CPU bekomme, dann stimmt das. Wenn du jetzt deine Bestellung absagst, dann ist das kein Problem. Du kannst natuerlich das 301 wieder kaufen, nachdem der neue CPU eingebaut ist.
Wenn deine Frage ist: Wird der neue CPU neue Firmware brauchen, damit alles weiterhin funktioniert oder wird die alte Firmware mit dem neuen CPU funktionieren? Ja der neue CPU braucht neue Firmware und Nein der neue CPU kann die alte Firmware nicht benutzten. Aber die Firmware wird fertig und stabil sein bevor der neue CPU zu haben ist. Mache Leute wollen den neuen CPU nicht haben oder kaufen. Das ist auch ok. Mann muss nur verstehen dass mit neuen CPU lauft es schneller, und das heiss man kann mehr Sachen dann machen. Alles was noch dem neuen CPU raus kommt funktioniert nur mit dem neuen CPU. Die alte Firmware für den alten CPU wird aber auch stabil sein und komplett.

I apologize if this insulted you. I’m only trying to help you.


It seems to me that it is not clear to @leverkusen (and by implication probably others as well) what the upgrade means. The details of the upgrade are scattered about in various discussions so I believe this is to be expected.

A few details about the upgrade:

  • It will not be available for at least 6 months. I haven’t even started designing it yet. (Edit: After receiving feedback, this timeline has been redacted. The CPU upgrade will be revisited after the firmware reaches v1.0.)
  • On the back of the ER-301 there is a small red board which holds the CPU and RAM. I purchased this board from Olimex. The upgrade would replace only this single board. See picture below.
  • Before releasing a CPU upgrade, the firmware for the original hardware will absolutely be developed to a mature and stable state. I will postpone the hardware upgrade if this is not the case. Even after the upgrade is available, any bugs found will continue to be fixed to the best of my ability and maintenance updates released.

The yellow arrow points to the part that we are talking about upgrading. You pull it off and push on the upgraded board (yet to be designed and manufactured).

As for worries, just tell me what you want and I will try to do it. I am still just in the planning stage. This is a discussion. I am not interested in building a business on people’s unhappiness. Questions? Please ask. Something not clear? Please ask. Is someone acting like they are working with incorrect information or false assumptions? Please take the time to explain to them.


The reason you’d upgrade your CPU is if you wanted to run more units. This is more like upgrading a CPU in a PC, whereas nothing is upgradable in an iPad. Also, from what I understand, the drop in will be pretty affordable. This is way better than having to buy a completely new unit and spend another $800-900. Most eurorack manufacturers don’t offer options like this which future proof the module and just create new versions.

I think everybody has good intentions here, so please keep it cordial.


Brian would this point invalidate my assumption that the new CPU would be able to run the old firmware? Will this CPU upgrade introduce a new architecture necessitating a recompile of the current firmware?


The CPU upgrade will absolutely require a recompile of the current monolithic bare-metal firmware. It will also require a rewrite (port) of the RTOS (hardware abstraction) layer. The application layer will mostly remain unchanged by the upgrade.


Ahh so once the new CPU is released any future development will require the new CPU.

Sounds great, especially since the old CPU will have a fully stable and capable firmware to continue running.


Brian, here are a few more questions I think might help clarify this potential upgrade for people:

Do you anticipate the new SOM will be an easy user install (e.g. no soldering required, no extra hardware/specialized tools)?

Do you expect a new SOM to be priced comparably to the AM3352 series (assuming some small price increase)?

Are you planning to resell them to ER-301 owners? (reason I ask is that it looks like Olimex direct has a minimum order qty of 10).


The old one can simply be pulled off and the new one pushed on no soldering required I think, see Brian’s post above where he is running through all the details


In my opinion, it is an easy user install. No soldering or special tools (well I recommend a popsicle stick).


No. I expect the cost to be at least 3 or 4 times the cost of the AM3352-SOM. This is not my decision. The cost of the more powerful processor and the more complicated board design is multiples higher. Take for example, the cost of just the CPU. If you look up the AM3352 (a Cortex-A8, the current CPU) on Mouser. You see it is more than $10 each when you buy at least 100:


To make this worth it we would want at least a dual-core Cortex-A15 like this AM5728. According to Mouser it costs $60 each.


Yes. Olimex has officially stated that they will not release another board with the same pin out as the AM3352-SOM. They have started working on another SOM standard which they are calling SOM24:


This means that at the very least I have to design an adapter board for whatever new SOM that I end up choosing (which might not be from Olimex). So, in the end, I will probably be the reseller because the adapter board will be a custom design.

This is not correct. The 37EUR price listed in large font is the price for a quantity of one.



Seeing this post immediately after your request as the mod for people to keep it civil is a bit jarring. @odevices s clarifications further down the thread indicate there will eventually be different sets of firmwares for each CPU, so I can understand where @leverkusen’s question and request for clarification is coming from.

As you’ve stated, this forum strives to be an open and welcoming environment. There’s a way to explain and/or correct somebody in that spirit, and I don’t think “completely and utterly wrong” is it.


Most boring thread ever, like people discussing the spec of the next iphone. I would rather see more fun units!!! heh heh :stuck_out_tongue_closed_eyes:

Joking btw, this actually could be favourable to existing owners if Brian plans to release an updated 301 im guessing the 301 production line will shut down leading to more available time to spend on the software woo hoo!!