How to Send Control Voltages from Audulus to a Modular Synth
  • You can send LFOs, sequences, gates - anything, really, from Audulus to a modular synth through your audio interface.

    You need a bit of gain, so it might not work well coming straight off an iPad, but I've confirmed that it works swimmingly using the outputs of my Apollo 8 interface. You can get more gain from a VCA module if needed.

    In this video, I have Audulus running in a track that's being sent through the new Endangered Audio Research Spectravibe pedal. The audio from the Spectravibe is returning through another track and being recorded there.

    I have a second Audulus instance running in another track that is just a couple LFOs and a sample & hold. The output from this track is being sent into the modulation input of the Spectravibe. The modulation starts at 1:30 when I turn up the Depth knob on the Spectravibe.

    Give it a look and try it out - I have 8 outputs on this interface and thus could have 8 different control signals running from Audulus to my modular. The trick to getting more outputs is to use it as a plug-in in a DAW instead of just as the standalone. In standalone, currently, you can only send to outputs 1 and 2, which are normally occupied by your monitors. However, like I mentioned, there's nothing stopping you from going straight out of your iPad into a VCA module and then into your modular rig.

  • This sort of approach also works well for Korg Volcas and I've used it with a Moog Minitaur as well. Proceed with caution if you're trying to route a signal out of Audulus into a CV input on hardware whose output goes into a USB interface connected via a camera connection kit to your IOS device for more processing and/or recording so that you don't create feedback loops. It can definitely be fun.

    With similar caution, you can also incorporate a mixer with amplification to increase the level/voltage of the signal sent from the iOS device to the mixer to the CV hardware input. Start off at zero signal with the mixer and slowly increase the volume until it's in a range where your CV controls are working as desired. This process is in some ways similar to setting the noise gate for an electric guitar signal input except it's being output from the iOS device to the hardware rather than vice versa. Eliminating electrical hum and line noise can be another issue in these setups as well as impedance issues where you can have signal bleed back.