Is it "ok" to copy a module?

We know you can’t copy the UI / artwork of a module and be allowed in the library. But what about copying the functionality of an existing Eurorack module. Just curious about what most people think about this.

For sure a lot of ppl come to VCV looking for “the VCV version of module xyz”, and some devs seem drawn to doing this. On the other hand much of the creativity and inspiration that went into formulating the idea and feature set of a module could be said to “belong” to the original module designer.

What do ppl think? (asking more about that “morals question” than a legal question).

The Ethics Guideline seems fairly clear. But, functionality is not mentioned.

I think it depends on the situation. If a module that is being copied or ported is a digital one and the developer’s job is “just” to create the interface (which isn’t too trivial, to be fair, and it could be hard) and tweak few things (which might also become a big adventure, to be fair again), that’s bad. Well, from my perspective.

But if this module is not digital or not “heavily” digital (like it has some digital components, but it’s not adruino with pots), that’s a different thing and I actually would like a lot of this kind of stuff. Like a bunch of Buchla clones (adding to what NYSTHI already has), lots of different filters, wavefolders and so on. So this way it’s not really copying, it’s like… re-modelling in a way.

I am not a lawyer, but it is my understanding that functionality may be patented. In that case, copying functionality becomes a complex international legal issue rather than an ethical issue.

Well, the question is about morality… And I think our legal systems are a bit outdated when it comes to copyright issues and modern technology…

**Not saying that we should ignore it though

In general, morals are about guiding principles and ethics are about specific rules or behavior.

It depends what you mean. Eurorack has a long history of evolution or permutations of an idea, e.g. DUSG - Pros and Cons of Different DUSG Inspired Modules - MOD WIGGLER

I have no issue with people putting a new spin or variation on an existing module, and personally wouldn’t want to police that.

Literally taking an existing eurorack module and reskinning is probably not ok, I don’t see that very often but could be wrong.

So, just to get it straight, you’re talking about a “clean room design” process of reverse-engineering the features of a physical module, right? It would be different from, say, using code for digital components of the module of interest.

As far as copying functionality in general goes, I dunno. You could argue that MicroSoft’s failed Zune infringed on Apple’s iPod.

Yes, clean room copy. And I’m not talking about legal issues. And I’m not talking about policing it. Just curious about ppls person feelings about doing this.

You are asking if I feel that it is morally “right” or “wrong” to copy an existing hardware device, specifically Eurorack modules.

My personal belief is that it in general is not right to copy such without the permission of the creator. In my mind, this is similar to my belief that it is wrong to plagiarize a written work in any significant amounts without permission from the author or publisher, except in certain “fair use” scenarios.

That’s just my feeling… but that is what you are asking for.


Do you have some examples in the library that you’d like to share/discuss? It’s hard to talk about it in the abstract for me at least

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It is my belief that all “intellectual property” is theft, and derivative work is never a moral or ethical concern.

Just in case I need to clarify: I don’t suggest ignoring the VCV Ethics Guideline or any relevant laws. This is only my personal feeling.


I would not duplicate someone else’s hardware without explicit permission. On the other hand, make a new module with a piece of hardware as inspiration, but different in a useful or interesting way – no problem! And simulating something historical where the originator no longer exists is interesting.

I guess there is a rewarding technical challenge to attempting to get as close as you can to some hardware. Otherwise, it just seems to be boring and unoriginal. There are so many great ideas around for modules that don’t exist yet .

no, I got nothing in mind, or any secret agenda… Mostly it’s just a topic that seems to come up from time time time. Usually, as I said, in the context of “vcv module foo is eurorack module bar”. Although the Behringer synths are good examples of physical devices that do this. They (I think) look and function exactly like the ARP or other synthesize that they are “copying”.

that seems a little extreme, but at least consistent. So for you personally it would be ok to take a movie camera into a movie theater (ok, only old people…), film the movie, and sell copies on the street? Or for Puff Daddy to take a hit police song and say “unh” on top of it and sell it as his own?

I can only speak for my modules and my intention for putting them open-source. One is to let others inspect my code to see how it is done. I learned a lot that way. The other is making a “better” version of my modules. I really welcome that.


if they’re intentionally open source, then we already have the answer: it’s legally allowed and ethically encouraged.

but it’s far less clear-cut with physical modules that do not have such a license.

personally i’d go for the “inspired by” strategy, in which a developer extends or otherwise changes functionality, so it’s not a direct copy. as an example i offer wiqid languor which is inspired by nonlinearcircuits’ triple sloths. i’m not even sure which strange attractors the physical module is using, so my module is definitely not a direct copy.

i think to most people this is acceptable, while some people feel differently about a direct copy.


In case of doubt, I would ask the owner for permission.

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Maybe a slight tangent…but many Eurorack modules are themselves ‘copies of’ and/or 'inspired by ’ (elements of) other modules or synthesizers. E.g. many emulations of ‘classic’ (often brand related) filters and other functional components.

Just enter any major ‘classic’ brand name (e.g. Roland, Korg, ARP, Oberheim, Serge, Buchla) into the Modular Grid module search box…

But, I digress, since we are mainly focusing on the ‘moral’ aspects of ‘copying’ a module. Specifically copying functionality (which is generally the main value adding aspect of stuff, except maybe for art)

Having said that, there’s the (more or less objective) legal perspective and the (more or less subjective) ethical perspective. Although even legal stuff like patents, trademarks, copyrights and intellectual properties are often not globally relevant (or…enforced).

First of all…to see where all that ‘copying’ and ‘inspiring’ might lead to, have a quick look at any ‘app store’ to find many examples of blatant ‘copies’ and/or ‘inspired’ derivatives. Same for many physical product (amazon/ebay).

Some are actual copies. Some have the added negative side that those ‘copies’ in fact might have little in common with the ‘original’, harming the originals reputation/business. Some are just ‘inspired’, but in a way that is very much traceable to some original source.

As @Squinky said we should respect other peoples creativity, hard work and interests, even if they are not always protected by law.

Personally, on the ethical aspect, for major concepts, I would at least try to respect the original idea/creator. E.g. by asking permission (even though that might not be legally required) or at least credit/reference/mention the source/creator. And explicitily distinguish between your product/implementation and the original/source.

Another aspect is that a VCV Rack module is NOT a ‘copy’ of a hardware module. A VCV Rack module can possibly emulate/implement much of the functionality, but is generally soon limited by factors like computepower, latency and all sorts of discrete digital aspects (as compared to dedicated physical analog and/or part digital modules). And, of course, there is the physical interaction aspect of hardware that is hard to ‘emulate’.

I guess in many cases VCV Rack is not even competing with ecosystems like Eurorack. Accessibility/prices being an important factor. There is even the case to make that VCV Rack is supportive to the physical modular ecosystem(s). Introducing people to modular/modules and stuff they might decide to buy later.


I’d say actually exactly copying a module is pretty questionable, even if it is legal. And when implementing and/or (re)combining very similar specific functionality/behaviour/elements, it would be the ethical way to at least credit the source.

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While certain expressions of an idea are property, I don’t really see an argument for ideas themselves being ownable, in the sense of being held back from others.

It’s hard to see how culture could progress if ideas were ownable. Once the first painting was made, should other people have refrained from making paintings? How about the first landscape painting? The abstract landscape painting? Would the world be better off if we refrained from being inspired by the work of others?

And more specifically around modules, even if you put the same knobs in and the same ports, there will surely be different implementations behind the scenes, right? A lot of the work was there, and as long as you’re not privy to those details, it’s hard to object to someone taking an idea into a new medium (hardware vs VCV).

Now, will the hardware manufacturer like it? Who knows? You could, as had been suggested, ask them, but their legal consulting will correctly tell them to ask you not to, because no lawyer got fired for hoarding all their client’s rights. But I don’t actually think that’s important, because, again, that’s giving them ownership.

I think that if you want your ideas to never be copied, the only way to do so is not reveal them to anyone. And that happens a lot! Painters guarded their paint recipes, and often their mechanical techniques. That’s fine!