Audulus and analog modular?
  • Ok, how hard do you think it would be to come up with a little Eurorack module, or even some kind of break out cable that would let users bus audio and cv signals between Audulus and Voltage Controlled hardware synths?
    Obviously audio is simple, but is there some way to get multiple channels of CV in and out of an iPad?
    Be very cool to see Auduls running on the iPad mini, mounted in a 3U Eurorack synth!
  • Would one of these modules do the trick?
  • The Expert Sleepers ES-4 module with S/PDIF interface is probably the simplest option with any Mac via existing audio interfaces that have S/PDIF connections. And even if you don't have that, you can interface S/PDIF directly to the Mac via its audio out with some low cost converts. (This link has more on that: But Expert Sleepers have other CV/Gate options that can directly respond from audio and ADAT signals.
  • Interesting and important idea!
    Expanding on that idea a bit, with guitar in mind......since any knob can be modulated, I envision the day that I have a pedal board composed of multiple expression pedals, each controlling different effects parameters in a patch or multiple patches playing in series and parallel.
    An iPad audio interface with multiple midi expression pedal inputs would do the trick here (haven't seen one) ...OR.... With existing hardware, such as a Quartet, a module that uses analog expression pedal resistance to modulate an AC carrier that would then be de-enveloped in audulus would be required (Quartet would allow for 1 audio and 3 CV inputs).
    Now, going one step further with option 2, above, a stand alone module that accomplishes this is the same problem as suggested by DCramer, requiring the same solution, with the only difference being that the analog pedals need a DC source to create the CV (I believe those expert-sleeper modules already use the CV voltages to modulate AC in order to get through an AC coupled interface).
  • If I understand DCramer's initial post correctly, he wishes to get multiple CV's in and out of the iPad, as do I.
    A module with an iPad class compliant interface is required.
  • @BTL, if any of the audio interfaces for iPad are DC-coupled then we could hook one of them up directly to the modular, I would think. We might have to build something within Audulus to handle calibration.
  • @Taylor,
    Are any of the iPad audio interfaces DC coupled?...I am under the impression that they are not.
  • @BTL, @Taylor,
    If the ES-4 module was used, you could do the S/PDIF interface trick on the iPad audio out perhaps?
  • @robinbenjamins, what's the trick? Also I think the S/PDIF needs special encoding for the ES-4, but maybe I could make a node for that :-)
  • @Taylor, maybe its not a trick but over at "Muff's Modules & More" form there is a discussion thread on how to use the Mac's audio out combined with a TOSLink and a TOSlink to Digital SPDIF Coaxial Signal Converter (Both of which are not that expensive) to get the S/PDIF directly from the audio out. For more details the thread is here
  • @BTL, I am also a guitar player and a composer. (Not professionally but strictly as a hobbyist.) I was a kid when “Switched on Bach” came out and was blown away by that Moog Modular, by its sound and its sight. Later I was in bands in the 80s and fooled around with Juno 6s, which were analog synths but controlled digitally. Fast-forward to today and I have one foot in the analog world with my guitar and stuff and the other foot in the world of DAWs and virtual instruments. Audulus was a great addition to my studio and resides in my DAW which is Apple Logic based.

    And very recently I discovered the amazing world of real analog modular synths! Eurorack, DOTCOM, etc. I am immersing myself in this newly discovered realm but somewhat struggling with how to merge it into my uber-controlled digital world. The appeal of the modular machines is the warmth, touch and feel of just tweaking knobs with that direct immediate audio feedback. The digital world is far more controllable, precise and rich with all kinds of capabilities compared to analog. But the digital world is somewhat antiseptic with a bit of “fun at a distance” feel to it.

    So my mind is trying to figure out how to combine the warmth, touch and even the unpredictable nature of analog with the control and repeatability of digital. And to also capture the performance of the human interaction of the analog machine, which is generally a one-off improvisation, and then to be able to record it and play it back through the same machine over and over again.

    Interfacing challenges aside, the goal I have in mind is to control an analog machine via CV and gates originating from a virtual counter part like Audulus and other modulators and controllers. This would also include routing the audio path from Audulus out to the analog machine and then back into Audulus. And then also do the reverse. Capture all the knob movements and maybe even all the patching routes during a performance of an analog machine. The real-time knob and patch states would be recoded in the DAW as MIDI data that can then be played back which should then be able to recreate the performance. (Yeah, I am really starting to dream here!)

    But the missing bit is a way to capture real-time knob and patch cord changes originating from the analog machine. That would require some new kind of buss and protocol that would need to be added to all of the hardware modules in the analog machines. That is going to require some bold module builder to implement such a solution and hope that it gets adopted like the form factor of Eurorack did back in 95. And maybe the guys behind Expert Sleepers are already working on something like that?

    I hope I see something like that soon.
  • I use an Expert Sleepers ES4 module to send CV from my DAW to my modular. To do so I can use Silent Way, which is ES's matching plug in suite, or BEAP, a Max environment that emulates modular synthesis down to using virtual 5v for signals.

    The ES4 uses the SPDIF out on my Firepod, which usually shows up as outputs 9 and 10 in Ableton, and is DC coupled, which is essential for sending useable 5v signals to the modular.

    I was hoping to use Audulus, but I just now tried to do so, and was unable to assign individual outputs on my soundcard. Audulus preferences show me only virtual interface and Firepod, with no individual out assignments to enable testing with the ES4.

  • @ENDIF, hm...I get the limitation. You can assign to the outputs but that would be at the level of S/PDIF stereo (out 9 & 10). Audulus would need have the ability to assign to a new sub category of outputs. Something like 16 sub-outputs for every output? Then that might be able to map to the CV/gate signals that the ES-4 is expecting? But clearly the exact specs/protocol that ES-4 operates with would need to be shared for this to move forward.
  • @ENDIF, you should be able to use the channel selector on the output node to assign output channels. Does that not work?
  • I've experimented with the Expert sleepers/Silent way stuff and it's amazing. My MOTU multichannel audio interface spits out CV from my iMac as is just using special cables (insert style).
    So yes essentially what I envision is a similar solution with Audulus running on an iPad, sending and receiving CV and audio.
    There is a module coming from "sound machines" in Italy called the rc1 radiostar that interfaces to iOS and Andoid devices and sends 16 channels of CV and gate out, doesn't look like any ins though, and the module looks very expensive! But Audulus could be programmed to drive that module, which would be tons more powerful than the sound machine apps.
    I rather envision a cheaper more flexible option with fewer CV outs but also CV ins as well as Audio in and out.
  • @robinbenjamins

    "But clearly the exact specs/protocol that ES-4 operates with would need to be shared for this to move forward."

    I don't think so, I'm able to use BEAP with it, I think the audio being sent to be used as CV just has to be in the right frequency ranges to be useful as CV, and the interface itself has to be DC coupled. But I could definitely be wrong.
  • @DCramer, ideal iPad interface would be 4 (or more) audio ins (for the way I like to run outboard effects- 1 dry plus 3 or 4 parallel effects), the same compliment of audio outs, 4 or more CV ins for expression pedals each controlling different effects parameters (for both audulus effects parameters as well as outboard pedal mix levels) and the same compliment of CV outs.
    As a live effects signal processor, the advantages are obvious. For recording purposes, the audio (both raw and amped and mic'd if desired) and CV outs can be sent to the computer DAW, keeping control of the effects at hands and feet reach. For takes that require more rehearsal, I could record all 4+ guitar tracks and associated CVs into an iPad DAW (Multitrack or Auria), chose my best performance take, twiddle with CV levels for best sound and then transport all off that to the computer DAW (in both cases, running audulus within) for incorporation with other tracks and final mix down, still allowing for dynamic changes and tweaks of the original effects parameters and levels to be made on the original track signals during final mixdown.
  • @Taylor, @Dcramer, @BTL, @ENDIF, what if instead of using the iPad audio interfaces, we use an iPad MIDI interface? That would make the hardware interfacing for iPads much easier with plenty of choices and must music users of iPads probably already have one.

    That would require a new outbound MIDI node in Audulus that can map any node’s output to the full range of MIDI messages including CCs. This would probably result in loss of waveform resolution but there are already many MIDI to CV modules out there so it must be acceptable. Some examples of these MIDI to CV modules are Doepfer MCV4 on the lower end and a Doepfer MCV24 on the higher end. And then there are the many MIDI modules in the Eurorack and other form factors that can be used for the interfacing to the modular.

    Adding a MIDI output node in Audulus would be great for Mac too and very useful in DAWs, which could record the Audulus control modulations and then map that to various other tracks and instruments in the DAW.

    That would open a whole new dimension to Audulus users.
  • @robinbenjamins,
    I too was an instantaneous original Moog fan and was also blown away by the sound and the new directions their equipment forged in the evolution of Rock and other music...and Wendy (Walter) Carlos's stuff was truly impressive, and in fact, helped make "A Clockwork Orange" the great mind bender movie that it was at the time. (I have also recently begun to look at modulars as well as expert-sleeper modules.)
    The desire to apply and capture (record) the human interaction in a recording environment goes all the way back to Neeve Flying Faders in the days of pure analog recording. I started my EE career in the professional recording industry (equipment manufacturing side) and had the opportunity to play with them. The thought at the time was that, eventually, all interactions could be recorded as technology evolves. The call for dynamic control and recording of track envelopes and effects parameters in today's DAWs is still big (and that would still only apply to within DAW effects).
    The only part of your requirement that would require special new protocols would be the recording of your patch cord connections. The rest is just the recording and transmission of DC and midi control parameters....and the fact that the overall concept still has not reached full fruition with today's technology is puzzling, to say the least.
    But this is a good thread to further push the boundaries and capabilities of audulus in that regard and should be kept alive and revisited now and then.....both for the purposes of audulus development as well as reviews of newly available equipment and interfaces.
  • @GrapeInfermal, I am not familiar with Isao Tomita but just now listening on YouTube and something new for me to explore. Sounds very good and I can see the comparison.

    When I heard "Switched on Bach" my friends were into "Partridge Family" and other bubble gum pop at the time, which I was not into. The Bach/Moog record was something that I grabbed onto and it mystified me at the same time. Both the compositions and sound. It had a big impact on me.

    But as I grew up and got more into rock I discovered Pink Floyd and then ELP which had that big Moog thing too. But then I soon discovered Jazz and, via the Fusion scene, discovered Weather Report. Man that was it for me. Their music and performances were off the charts!

    I got talked into being a bass player in an original band during the 80s New Wave genre. Got my hands on real synths then. The Junos and DX7s. Learned more about music, composition, recording and the studio tech. (I am also a bit of big tech head.) After that part of my life ended due to the reality of wife, mortgage, kids, the crush of life, etc, I got back into music as a hobby in 97. I discovered I could still learn and started to teach myself guitar. Got crazy with the guitar and equipment. That lead to composing my own stuff and DAWs, virtual instruments, etc.

    Guitar is big on old school analog for the best tone. Tubes are a big part of my rig. And I have a very cool home studio that I can do just about anything with thanks to Apple Logic and all the interfacing equipment. I have a nice balance between the analog and digital worlds and can use that to get my ideas out. (here are some of my compositions: The move into analog modulars is just a nature progression for me. Its gonna be a lot fun!

    But recently I have realized music is changing again, which is evident via the rise of EDM. EDM was a style that I was puzzled about. People say that New Wave hurt the guitar because of all the synth dominance. But EDM is really going to be the death of guitar or traditional bands general. And that is because a lot of young computer generation kids are going to learn GarageBand instead of a real instrument and make great sounding stuff influenced by the popularity of EDM, which is heck of a lot easier than working real hard on guitar for many years to only get a so-so recording.

    But I am not complaining. Just did not see that one coming. And interestingly, I have my foot in both camps. I actually like what is happening in EDM. Always good to inject orthogonal change into the evolution of music. Thats gonna be fun too!
  • @ENDIF, I was not sure what BEAP was but did some poking on Google which lead me to Ableton Live with Max. Reading, downloading...oh boy, mind mind is bubbling again.

    I have Ableton Live 8 but I am able to be more productive on Apple Logic. But just skimming the videos on Max and reading about BEAP is making me reach for my credit card so I can upgrade to version 9 with Max 6. I will get back on this thread as I learn more about it and get my hands on it.

    Way to many things for me to immerse into. Just my darn day job is always in the way. But I got a two week holiday break coming up so I am going to whip up a new tune that will feature Audulus with some EZ Drummer driving the beat. I want to go for that classic Moog sequencer bass looping sound. I want to also maximize automation on the song and modulate Audulus with it. That will add a new dimension of sonic morphs, sweeps and hopefully, some mayhem to the song.
  • Wow this thread is getting broad! I too fell in love with both synths and Bach in high school once I heard the original albums. That got me into Tomita (genius) and Debussy and I studied composition in college. I got into hardware and software synths in a big way and after years of software am building a Eurorack.
    Yes MIDI would work to send CV stuff to hardware. In fact using a Quenexus which works with an iPad, you would just need to send midi to the correct virtual port on the Quenexus and it would spit out CV.
    I was kind of envisioning a little module as it would be a slick solution that would be very popular with the Euro guys!
  • My ipad is too old (gen 1) to handle anything more than midi, so I'm working solely in the mac version of Audulus.

    Was anyone able to find where or how to route audio to individual outs on a given soundcard in Audulus for mac? @Taylor
  • Yea...looks like midi is the way to go....on the input side for my considerations, in order to get multiple expression pedals inputs through the typical single port iPad interfaces, I am currently looking at midi pedal controllers (one for each pedal) and a midi merger.....definitely not a cheap solution however.
  • Oh jeez. Yeah, sorry. I'll go mess around with that now. =P
  • You can see from the video that controlling a hardware modular could work if I were able to feed it voltages in the correct range instead of audio. I just wanted a quick test for proof of concept with Heptad2 and changing the main outs to 9 and 10 for spdif.

    No doubt those of you that are already far more familiar with Audulus than I already know exactly what needs to be done to make it musically useable. =]
  • Wow! Heptad never sounded good!
  • Perhaps someone can make a subpatch that can be inserted into a given signal chain to feed out voltages in the -10v to +10v range on a 1/v octave scale.

    Or maybe the functionality is already there?

    All one needs is an audio interface with DC coupled outs and you've got yet another reason to use Audulus. =]
  • @ENDIF, cool, progress! I'm assuming that the normal range of -1 to +1 that the audio driver expects are mapped to the -10v to +10v range by your hardware, so we should be able to come up with a little expression via the Math Expression node that will map the values.

    - Taylor
  • What a great environment. I've been having a great time just mapping things to the output that feeds the modular and sending it various places, or crosswiring bits inside existing self generating patches that maybe shouldn't ever be. =]
  • HEPTAD 2, Hendrix interpretation!
  • Very cool video!
  • @ENDIF, I was going through the ES-4 hardware and Silent Way ES-4 Controller plugin documentation and gathered that the ES-4 hardware is best driven by the ES-4 Controller plugin software. If you are intending to route audio to the ES-4 hardware CV outs, the "Input Mode" section of the ES-4 plugin is where it appears to gets mapped from an audio source.

    What I am suggesting is that you connect Audulus to ES-4 plugin and then the ES-4 plugin will connect to the ES-4 hardware via the S/PDIF connection instead of going directly from Audulus to the hardware.
  • @robinbenjamins, I'm guessing the because Silent Way is designed to operate with a typical DAW, it converts MIDI to encoded values on the CV outs (@ENDIF, please correct me if I'm wrong). So it would be valuable to be able to convert signals within Audulus directly to analog CV.

    - Taylor
  • @Taylor, @ENDIF, The more I have been thinking about this the more it might be useful to have Audulus output three types: audio, CV, and MIDI.

    Audio is natively there and can interface into modulars via instrument or mic input modules. The down side with this approach is that there is no gate or triggering signals available.

    CV would still need some kind of hardware output interface. My assumption is that the MOTU DC coupled approach that SilentWay uses is going to be the same type of solution for CV. Depending on the source type you still may need a way to get gate/trigger out, which is why the MIDI out option could solve that.

    The MIDI out option may appear to be a little strange but it could offer the easiest interfacing and provide gate and trigger outs to complement the other two as well as other modulation signals via CC messages.

    A MIDI out node in Audulus would need to have several inputs to route various signal sources and types to map and transform them to MIDI note pitch, note on/off, pitch bend, velocity, cc messages, etc. (I guess deriving note pitch would need some kind of quantization process.) All the node's input signals would be merged into a user selectable MIDI channel. The hardware would be typical MIDI out interfaces for Mac and iPad which would then be connected to typical MIDI interface modules on the modular synth.

    The point of having the three output types is to insert Audulus into the modular synth's path and allow the analog modules to interact with any number of nodes in the Audulus patch. With bi-directional signals, Audulus could be a tool for users to define their own module designs in real-time.
  • I had already mentioned the Qunexus keyboard, which runs directly on the iPad and can work as an interface, sending cv out in response to MIDI coming in on port 3. Then there's the RC1 radio star from Italy, an expensive but full featured Euro module, and finally a little Euro module kit called CVpal, a cheap midi to CV interface with a USB port on it. It's designed to plug into a host and convert midi to CV and could run directly from an iPad. Really there are 2 sides to this; 1 the hardware to get CV in and out of an iPad, and 2 the app that can create and process CV like signals. The beauty of Audulus is that it's the perfect app for creating and modulating CV signals. Maybe pairing up with a hardware manufacture to the hardware interface?
  • What a great thread, so many good ideas!


    - One could totally run the SW plug in inside of Audulus as host, and solve all of this, as you observe. I just think it would be cool if Audulus could do it natively, to merge the two worlds without a third party bridge. =] Maybe it could be done better.

    - If you notice from the video, all the outputs on the ES4 and gate submodule were reacting to the audio signal I was feeding it, ditto for the envelope. SW does some multiplexing that allows it to assign different signals to each CV out, and up to five gate expander submodules.

    - Yep, MOTU DC coupled audio interfaces are a great solution from what I hear.

    SW uses routing and multiple channels and plug ins to send midi to a SW audio plug in that then sends that CV range audio to the module via the chosen input type (lightpipe, spdif, audio ins, etc). So I'd create a midi track, route the midi to the audio track running SW, which would then be sent to out 9-10 spdif. All of which makes so much more visual sense in Audulus, being modular and not a traditional DAW.

    I think perhaps the Output node could have an additional command added to allow CV range signals, and one could simply add a new output node, switch its range, and assign the appropriate output channel to the DC coupled hardware.

    Is there value to doing something like that in reverse for the Input node?
    For example..

  • @Dcramer
    Also excellent suggestions! I may have to get a Qunexus or one of those others after I upgrade the ipad. =]
  • @ENDIF, The Moon Modular 552 CV to MIDI module is exactly what I was trying to describe in my comment on a new Audulus MIDI out node. Having an Audulus node implementation of the 552 would allow Audulus to modulate DAWs similar to how CV works in the analog modular world because "MIDI is the CV" of DAWs. And on he subject of a MIDI out node, the MIDI in node, which is the keyboard node today, should be enhanced to include more options that can map the wider set of the MIDI protocol to other Audulus nodes.

    In fact, if you are familiar with Plogue Bidule (, the routing of audio and MIDI of physical and virtual inputs and outputs would be a very powerful in Audulus. Not suggesting to go as deep with all the routing capabilities but to implement a basic set of routing capabilities would go a long way. And then to be able to send audio/CV to MIDI and back would be something very different.

    @Taylor, any thoughts on adding a MIDI out node to Audulus?
  • @robinbenjamins, I was thinking of adding three MIDI out nodes actually: Control, Program Change, and Note. I think that will cover the bases, right?

    @ENDIF, I like your idea of having a separate output node for CV signals. It would presumably handle the calibration required. I'll have to research this in more detail.
  • @Taylor, Adding a MIDI out node with Control, Program Change and Note would be a big step forward and would be fantastic. For Control messages I am assuming we would have a way of assigning the CC number (0 through 127) of each instance of the MIDI out Control node? That way Audulus could use the CC message types as channels to modulate a large number of controls in other plugins and programs.
  • @robinbenjamins, that's right. The CC out node would have both CC number and MIDI channel parameters (they would be menus rather than inputs). It would have a value input and a trigger input (to trigger sending the message).
  • @Taylor, So in a case where I wanted to use an oscillator in Audulus to send out its waveform via MIDI to modulate another control in an external plugin or program, I would do the following: Use CC 1 (or any other CC message number) and set an oscillator to the trigger input, which would set the sample rate of the value input. Then set a different oscillator or other waveform source to the value input and its waveform would now be seen at the external plugin's control. Have I got right?
  • Taylor, so I don't know if you've tried something like the Qunexus yet but when it's plugged into a host via USB it communicates via 3 different virtual ports, I think one drives the lights, one the CV outs and one MIDI. It would be very cool if Audulus had access to each port. I know it's based on class compliancy but have no idea what that means in terms of programming.
  • @robinbenjamins, precisely!

    @Dcramer, I'm going to order a Qunexus right now :-).

    And if either of you (and @ENDIF, or anyone else) has some suggestions on some starter eurorack modules so I can test Audulus interfacing w/analog hardware, I'm all ears.

    Any thoughts on this: (its cheap!)
  • I've done some tests with my iPad 2, Qunexus, and hardware.
    I was able to get a couple of apps to send MIDI to the Qunexus on virtual port 3 which then sends it out as CVs to my my hardware modular. This should mean it would be very simple to send controllers from Audulus out as MIDI, converting them to CV in something like the Qunexus.