Surge - a new module collection from a great digital synth

Hi folks.

I’d like to invite super-patient alpha testers to give us feedback on a project which is bringing a new set of modules to VCV Rack 1.0.

The Surge Synthesizer was created originally in 2005 by Claes Johanson, now a principal at Bitwig. In September 2018, Claes realized he was never going to finish his 1.6 release, and rather than abandon the code, he released it GPL3. A group of us have been working on the synth, and the VST/AU version for Mac, Linux, and Windows is available at the website. If you use a DAW which hosts plugins, let me encourage you to give it a spin. And if you want to get an idea what it sounds like, the One Synth Challenge group used Surge in April, so here’s a set of songs made using only Surge.

The synth is amazing. In the plugin version, it has 6 oscillators, 24 LFOs, a full effect bank, amazingly fast filters, supports full MPE, uses hand crafted SIMD instructions to do very low CPU high performance stuff. Really neat. It’s been fun being part of the team restoring it to a release.

But I had the idea a couple of months ago to break the plugin block diagram down and make each part of the block diagram available as surge modules. That project is called surge-rack. The project uses the surge DSP engine but factors it into panels which you can intermix with the rest of rack 1.0.

So that means that we have a project now which introduces

  1. Classic digital oscillators
  2. A multi-mode wavetable oscillator which ships with hundreds of GPL wavetables
  3. An entire bank of effects (Delay, Chorus, Pitch Shift, Vocoders, Reverbs, Distortions)
  4. A multi-mode waveshaper
  5. A multi-mode envelope generator
  6. An LFO with both free-run and envelope gated systems
  7. (Coming soon) a VCF and FilterBank. These are not done yet.

We are pretty excited.

Right now the software is in an alpha release for very patient people. Many modules have place-holder face panels (most of the FX have a workable generic panel for instance). We know there are some conditions that generate clicks and pops. Everything is monophonic. The parameter display options V1 give us aren’t used yet. The filters aren’t there. We haven’t supported TempoSync properly in the envelope. We have a list. But that list is too short and we’d like people to help us make it longer.

So what I’d like to ask is: Do you feel like testing some alpha modules and helping us find bugs or giving us feedback or (if you are interested) working on fixing bugs in the code? We are especially interested in people who are experienced rack users who can tell us if we have done things which are consistently weird or wrong.

You can get the modules by building them yourself if you want, but also we build a new binary alpha version V1.0 mac win and lin automatically with every push to our master branch. That overwrites versioned releases at - and since we create them with every push to master there are a lot of releases. I think there have been 6 this morning!!! So if you do use it and file a bug or feedback request please make sure to let us know which version you are using.

Finally: we’ve worked super hard in the surge project to have a constructive and polite community. Everyone is welcome and we hope you’d bring a cooperative polite spirit to the project. If you have used a lot of modules and can write clean bug reports or constructive feedback ideas into GitHub issues or as comments on this forum, we would really welcome them. We’re all nice folks. @oddy.o.trax has been especially useful in finding bugs so let me tag him here also so he sees this!

Look forward to any and all feedback. And I hope to get those filter modules together soon too.


Incredibly excited about this and the work that you and the whole community have been doing! I won’t have a chance to try these out immediately but when I do I’ll put on my bug-report cap :slight_smile:

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Haven’t really got the time or knowledge to be able to test this but I can’t wait to try the release, the plugin is a beast.

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I have used the surge rotary extensively so far but not much else, it is very user friendly and seems to work very well. Looking forward to time to take others for a spin. Love that they are being ported into Rack modules rather than just staying in VST land!


Wow, this is awesome. Thanks! I’ll definitely download it, play around and report any bugs I find.

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Damn it is AMAZING!!! (


True, still have some bugs. Because it’s still beta?

I wish it was beta yet! This is cutting edge alpha.

Reports on bugs you find are very valuable to us!!

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WOW! THIS IS AMAZING! I’m a longtime user of Surge since 2006, It’s my main tool in everything I do, I have a huge preset library that I’ve made.

I’m sooooooo looking forward to this!

OBS: The crack version of surge 1.5.2 works better then the newely relesed beta somehow.

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We just (literally 2 hours ago) released 1.6.0 of the VST/AU (not of the rack modules - those are still alpha) and most folks think it works well. If you have specifics for the way it works worse than 1.5.2 though I would love to know but that’s for over at not for here.

True! 1.5.2 is still better. (I have try 1.6.0 also).

So: If you have ways that 1.5.2 is better we would love to know them. They must be obvious since 1.6.0 was only released literally 20 hours ago! But none of us have 1.5.2.

So please do feel free to drop those in as issues there.


I played with the Surge VST last night, it is very powerful and I have only scratched its surface. This can be my intro into polyphonic synths. Have to say I am looking forward into bringing Surge to Rack.

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Just as a sneak preview here’s a little demo I made of the surge vocoder running in rack. (In this case I used loopback and logic as the sound sources but the routing and processing is all rack as I hope you can see)


This sounds really good to my ears, but its 1.0 only?

Any chance you could try Nysthi SAM through it? Because that’s the first thing I would do.

Yes it is 1.0 only.

You can route anything to it yeah! My dev environment just has surge-rack BaconMusic and fundamental but if you can build 1.0 plugins and are running 1.0 you can grab it from GitHub and try today!!

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Here’s another fun preview. I’ve been making everything polyphonic and also doing some profiling Here’s a multi-osc polyphonic voice set playing one of the midi files from the BaconPlugs poly generator.

You can get all those modules right now if you build surge-rack from master. All the changes are in the code. As you can see, more of the modules are getting proper faceplates as well as polyphony. In this example, only the Delay unit has a generic face.

Will try and get this into the community release before I do some travel at the end of June. Again, feedback and tests welcome.


Haha, used to be able to play that on piano but I definitely don’t have the muscle ability anymore for that.

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