Based on an idea by Leonardo Laguna Ruiz (Vult) on Facebook, I tried to connect VCV Rack to my Eurorack Modular.
The idea in itself is quite simple: use a Teensy 3.2 Board (about 20 €/$) as an Audio Card to send modulation signals from VCV Rack to Real Eurorack Hardware.
Most Audio Cards (at least the less expensive, usually) are not DC-Coupled and they cannot “send” CV signals to the outer world, they would filter (block) that voltage and output zero/nothing.
The Teensy can be seen by the PC/Mac as a USB Audio Card and doesn’t have any “blocking” of CV Signals.
You need to solder some components and possibly the Teensy header pins, I won’t go into details here (it’s a work in progress even for myself) but nothing too complicated.
On Leonardo design, you would need to add and OpAmp to “amplify” the signal coming out of the Teensy, but I couldn’t actually get it to work so I simply connected a cable to pin A14 on the Teensy straight into a Jack to test it.
The Output level was not very high, so I had to use a VCA on my Modular to add gain to the CV Signal.
In the Video you can see the same LFO sending a CV signal to the V/Oct input of both a Doepfer A-110 2 and Fundamental VCO-1. I needed to attenuate the signal going to the VCO-1 until both VCOs were more or less in tune and responding in the same way to the LFO voltage.
And yep, taht worked!
I will follow up on this matter, and when I have some stable and 100% orking circuit I will post schematics and possibly some instructions as well