VCV Rack vs Eurorack: Is There A Sonic Difference?

The latest loopop video is a provocative one – comparing the sound of VCV Rack modules against their hardware Eurorack counterparts.

VCV Rack is a free, open source software synthesizer that’s available for Linux, Mac & Windows. It’s currently in beta, but has already developed into a capable platform.

One of the unique aspects of VCV Rack is that the developers have ported over a dozen Mutable Instruments modules to the platform, including Braids & Clouds. These are some of the most popular modules in the Eurorack format, so they offer great opportunity for comparing the sound and capabilities of these designs in Eurorack and software format.

This comparison is limited to digital modules – but demonstrates that VCV Rack is already a powerful synthesis platform. We’d like to see comparisons of its virtual analog modules to hardware counterparts.

And VCV Racks’s capabilities offer a compelling argument for looking for new ways to integrate and cross-pollinate between hardware and software synthesizers.

You can find out more about VCV Rack at the VCV site.

Check out the comparison and share your thoughts in the comments!

Here’s what loopop has to say about the video:

One of the really interesting things about VCV Rack in my view is, besides being open source and free, that it comes with free versions of Mutable Instruments’ modules, some of the most sought after and successful eurorack modules. Controversially, Olivier (Mutable CEO) has decided to discontinue some of the most successful ones… yet the most admirable thing he does is to open source the code for his modules, so they have the potential to live on and evolve forever.

The big question I had is, how do they compare to the real thing? If the differences are small or even unnoticeable, VCVRack can become very disruptive.

I picked three of his most beautifully sounding modules (in my view of course…) Elements, Rings and Clouds (which is has been discontinued!) – and I compare the sound of the hardware to that of the software. These modules are digital, so they have a good chance of sounding similar, but DAC and other hardware magic or software tweaks might make a difference.

35 thoughts on “VCV Rack vs Eurorack: Is There A Sonic Difference?

  1. It should be all about making music, not whether a particular module/synth/device sounds *exactly* like something else. That’s stuff best left to engineers and technology collectors. Everyone else should be enjoying the golden age of affordable synthesis and making music/noise/drones/sample collages.

    1. These comparisons are valid and useful, though, for several reasons.

      First of all – there are lots of people that think, for whatever reason, that hardware always sounds better than software. In this case, the code is the same, but there will still be people that think that the magic hardware pixie dust makes a difference.

      Second – the fact that the most popular modules in Eurorack are also available as free downloads opens up modular to tons of people that couldn’t afford it in the past. That’s huge, and it’s important to know that VCV Rack isn’t something that will be sonically inferior – just a different platform with different capabilities.

      Finally, seeing and hearing this comparison makes me hope that somebody like Olivier Gillet will come up with improvement to the Eurorack standard that would allow for the type of patch memory that software allows, for transferring patches back and forth between platforms., and for using the modules as hardware controllers for the software. That’s probably fantasyland thinking, but it would definitely be technically possible to create a switchable buss system for interconnecting modules that could be overridden by patch cables.

      Kudos to loopop for the video – the only significant sonic differences I heard were a result of differences in where you need to turn knobs on the hardware and software versions of the modules. This is to be expected – and only matters if you’re trying to make a video like this.

      1. “First of all – there are lots of people that think, for whatever reason, that hardware always sounds better than software.”

        There’s a good reason for this, because 99% of the time, it’s true. I don’t know the science of why that’s the case, only what my ears tell me, and it’s not hard to hear the difference in person.

        I’m not a hardware snob by any means, and would love to close the gap between hardware and software. Maybe some software developers can chime in on why the sonic disparity exists, I’d love to know more about the how and why of the matter.

        1. Is it the magic hardware pixie dust that you like?

          I can understand why people like working with hardware over software, but arguing that same software, running on comparable processors, is going to going to sound significantly different makes no sense.

          Especially when you see a comparison like this, and realize that nobody could hear the difference in a blind test and know which is which.

          They only way your argument makes any sense is if you think that digital-to-analog-conversion and analog-to-digital conversion is adding something important to the sound.

          1. There IS a sound difference between analogue and digital (doesn’t mean either one is better), but I don’t see how there could be a SOUND difference between digital hardware and software, if they are running literally the same program.

            However, there is a big difference in user interface. The way that you interact with each will probably be different and therefore likely to lead to different sounds. Once again, neither one is better, cool music can be made on both, but that doesn’t mean there isn’t a difference. You don’t have to be reductive and label that difference “pixie dust.”

            1. AuxOct

              No argument that UI does make a difference!

              There are obviously huge advantages to having these modules available as software.

              With VCV Rack, you can do things that would be impossible with current Euro hardware – like adding features to existing MI modules (like patch randomization) or saving and recalling patches instantly.

              But even with those advantages, there’s no denying that a lot of people are going to find patch cables and knobs a lot more fun to work with.

              The topic of this post is asking whether there’s a sonic difference between VCV Rack and Euro hardware – and specifically the sound of the MI modules.

              That’s where I say that, if you think there’s a difference, it’s down to the magic hardware pixie dust – because you’d have to argue that degrading your sound with multiple analog/digital conversions is magically making a big improvement to your sounds.

              1. Yes, I agree.

                A software version of, say, Clouds will obviously sound the same as the hardware version because the thing making the sound in the hardware version is ultimately. . . software. I think analogue/VA is whole different matter, but that’s not what you mean.

                I think it would be a lot more fun to patch and wiggle a real hardware version, but there is no way I can afford $200 bucks for a powered box and another $300-400 for Clouds alone, so I am happy that I have access to the software version.

                That isn’t to say a real hardware version wouldn’t be worth it if I had the dough (in my case, I really wish I did have), but it is very cool that I can play around with something similar for free.

    2. I’m sure they sound very similar, being the same code and all. But can you turn 2 knobs at once on the VCV? Can I turn the timbre knob and the color knob and reach over with my pinky to adjust the modulation simultaneously? This is the type of thing that defines an ‘instrument’ and makes playing hardware much more inspiring.

        1. For that matter you could turn 3 or more knobs at the same time which is something you *cannot* do on hardware!

  2. It‘s intersting that vcv handles audiorate modulation pretty well, that‘s something i wouldn‘t have expected. Even real digital modules like the shapeshifter don‘t do this, mi uneducated guess is that the power of modern Computers comes in handy with that task.

    1. There are a lot of digital modules that handle audio rate modulation just fine.

      At this point, if they don’t, it’s really a limitation of the design, rather than what hardware is now capable of.

  3. In the modular hardware synthesizers, the real difference is the manual contact with knobs and cables. Programming a modular software synth is boring and not immediate. The real innovation would be if a version of VCV for ipad came out. Thanks to the touchscreen we would have a greater interaction. There are already examples of modular for ipad as the moog modular really usable with a feeling similar to that of a hardware.

    1. I never really considered rubbing your fingers on glass to be a really “physical” experience.
      At least with a mouse pointer, you have the tactile response of the “click”, which you don’t even get with a touch screen, and you can see the area of the screen where you are clicking instead of covering your finger with it.

      1. Yes, but the ipad system is the only one that guarantees a stable and secure standard performance. In fact, on the stage, you use the ipad for so many functions, while Android-based tablets are not seen at a professional level. About touch-screen computers (like Surface) do not work as a tablet, and it’s much easier to use an ipad.

  4. As a long time me Euroack user, I’d expect most digital modules, by themselves, to sound better in the box than in the module. The code is the same and the laptop has exponentially more prosseing power than the teensy, or pic processor that drives many modules.

    Any sound difference often results from the rack not the module. In the rack, the patch frequently includes an analog stage (a filter, mixer, waveshaper or whatever), that adds imprecision and noise and influences the final sound product. Not that such imprecision can’t be simulated dgitally.

    Ultimately, I think the magic of modular systems (hardware or soft) is more about modulation options than a module based architecture.

  5. … one thing beside the difference of tactile/physical patching and turning the knobs with your hands and the absence of a computer, is that this specific digital/software modular probably won´t exist anymore in 10-20 years because of new computers, software, etc.
    What i want to say is that the “real” modules will last without updates…you still will be able to power them up in 2020. (hopefully!)
    …just to get that thought in here…
    not more not less

    1. I get that argument – but I think that you have to balance that with the fact that proprietary hardware gets more expensive and harder to maintain over time, while mainstream computing hardware basically gets to be cheap and disposable.

      So if you want to get a digital module like Braids repaired in 10-20 years, you’ll have to be a surface-mount electronics guru or go to a specialist and pay a lot of money to get it fixed. . And as they get older, they’re going to get more valuable. And, if you want to add another module, it will cost you hundreds of dollars.

      Meanwhile, computers just get cheaper and cheaper and more and more reliable. There are plenty of people. too, that keep older computer systems around to run valuable software – so that’s always an option.

      I think the point of this is that Mutable Instruments’ module sound great and are the most popular Eurorack modules that you can get – and they sound exactly the same as software that you can download for free.

      This fact is amazing and liberating for musicians. It’s going to open up modular to a lot of people and it certainly makes me reconsider how to invest my synth budget. I may be spending more on analog modules, synth they’re harder to reproduce with software.

      1. you are totally right that if a module is broke in x+years, it will be gone…or very expensive to fix.
        i was thinking in a way of value and maybe having the real module that you can touch…that´s so hard with software to do.. 😉

        and yes, it is indeed very liberating for the people that can´t/won´t afford a modular system, to use software (Free…just imagine that!) …BIG UP! to the VCV Rack developers!

        …but still preferring the real ones… :-)…not only in modular.

  6. When it was first released I compared VCV Tides and the hardware. My ears are far from golden but I could hear a difference, the hardware sounded slightly better/richer

  7. I was thinking of this the other day… Even in a digital synth, or a PC, the last step, and potentially the most important is the DAC at the end…

    Uber high-end DAC’s cost several thousand dollars… So a digital synth, or a hybrid, etc. that costs like $1500 must have a DAC that’s at most in the hundreds of $, right?

    So a PC with a high sample rate going out a $1000+ DAC could maybe sound better than a $3K modular or HW synth.

    Orrrrrrr… There’s no reason to spend more than $50 on DAC’s…

    If high-end DAC matter, then it stands to reason a synth with less than the best DAC can’t be the “best”… Or something like that…

    1. I agree with a lot of the POV’s here on both sides of this debate and while I enjoy using hardware (and own a fair amount of it) it’s hard to argue with the power and availability of software like VCV! Drumunkey brings up a really interesting point here however that I think is overlooked by a lot of these posts arguing the sonic merits of hardware or software. It’s hard to argue against a high quality DAC sounding better than a cheap one. What”s important to understand is that a module like Mutable Instruments Clouds for instance not only has a built in DAC but also a built in ADC and the entire module is about $300, so it stand to reason that the DAC and ADC are fairly cheap. Is it possible that the sonic differences between the VCV version of Clouds and the hardware version is mainly in the quality of the converters? Taking that possibility further, some people may actually prefer the sound of the cheaper converters that are in the hardware. I really love the sound of my older Lexicon hardware reverbs for instance, and those were very low quality by today’s standards of ADA conversion. I think in the end, it’s all what you like to use from an ergonomic standpoint and the sounds that resonate with you on an emotional level. I will continue to use my hardware Clouds module with my high end Apogee converters, but I’m also going to check out the VCV software. Nonetheless,, ADA conversion is something to consider in these debates over sonics…

  8. Frankly I’m surprised at how similar these sound. With headphones on and scrutiny, I can’t honestly say I think one sounds better than the other. I thought for sure there would be some kinda “magic hardware dust”, some kinda coloration from electricity passing through metal in the hardware at the very least.

    All this being said, I’m currently one of those guys trying to get off the computer (and ipad) as much as possible, so the hardware wins my preference for that reason. Still, it feels frikkin insane to try to argue paying for thousands of dollars in hardware to achieve essentially the exact same sounds I could do for free on the computer. It’s like paying to be off the computer.

    Ultimately it’s about fun for me, as I imagine it is for most people here. If I can’t manage to have fun with the free stuff on the computer, then I guess that’s my problem. If others can have fun with the free stuff, more power to them! Like some of you already stated here, it’s great how VCV is making the art of modular sound making available to the masses.

  9. In the debate whether software synthesis can sound as good as hardware, I am definitely someone who wants software to narrow and eventually close the gap. I’m rooting for software. And there is no doubt it’s getting better, especially in the last few years. But folks, if you are honest about what you are hearing, there is still a gap. A shrinking one, but it’s there.

    This particular test is flawed because the programming examples aren’t close enough to each other. I think that doing parameter randomization in software, then trying to duplicate the settings in hardware makes it too difficult to get really super similar settings in a short amount of time. The differences in these examples are huge because knob positions aren’t the same. We can’t judge fine differences between them because the setting arent similar enough.

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