WARNING! Make sure your soundcard can handle the hot output levels from your eurorack synthesizer system before you make any connections.
In this article we show how to solder a 8 channel audio cable and attach it to the Otto Passive.
This is only for inspiration. In your case you may have other connectors, another number of connectors or a different need than to connect the soundcard.
Building instructions
- Use a shielded mono cable and cut it into 8 peaces with the same length.
- Remove the isolation on both sides of each cable.
- Solder the plugs/connectors on one side of all 8 cables (picture 1).
- Use a female header with 16 positions and bend out every other solder pad (picture 2).
- Solder all the 8 cables to this female header. The first pin is jack 1 signal and the second is GND. The third pin is jack 2 signal and the fourth is GND. And so on… (picture 3).
- Make sure not to make any shorts! Use a multimeter for testing!
- Mount the Otto 8 Passive in your rack.
- Connect the header to the top 16 pins on the backside of the Otto 8 Passive.
- Connect the 8 connectors to your soundcard. In this example we have connected all 8 cables to 8 inputs of a multichannel soundcard (picture 5).
- We have cut out the word “IN” from a sticker and put at the top of the front panel.
- Now it’s really easy to connect your soundsources to your soundcard.
Now you have easy access from your eurorack to all 8 inputs on your soundcard.
In the picture above you will also see another Otto 8 Passive with the label “MIX”. That module has the Single-Op KIT addon where you can create a 6 channel mixer. See here for more information.
On the backside we have connected the break-signal from the output+ (pin 31) on the “MIX”-module to the break-signal on the “IN”-module for jack 1 (pin 17). We have used a female to female dupont cable. A second dupont-cable for GND from pin 32 on the “MIX”-module to pin 18 on the “IN”-module.
With this arrangement, we now have a simple 6-channel mixer normalized to input 1 on the soundcard. If we insert a plug into jack 1 on the “IN”-module we override this normalization and connect that signal directly to input 1 on the soundcard. If we insert a plug to the output+ jack on the “MIX”-module, we also break the normalization but now we tap the mixer output to our inserted cable instead.
You can expand this thinking with more mixers if you want.