WARNING! Make sure your other device can handle the hot output levels from your eurorack synthesizer system before you make any connections.
Some devices and modules have pins on the backside that are designed to be used for signals in a eurorack synthesizer system. For example the manikk SHMIX mixer module.
Simple connect with dupont cables
You can use female-to-female dupont-cables to connect the pins on the modules together.
The SHMIX has two extra mixer inputs on the backside. One with a capacitor in the signal way, and one without a cap. Each signal also have a GND pin. So in total you need 4 dupont-cables for this example.
Be careful when you make the connections so that you connect the correct pins!
DIY add-on
If you want to add your own custom things to the Otto jacks, you can create this with a female header, a pinstrip and veroboard.
Solder the female header flat on the backside of the veroboard. When you attach your little add-on, it will point backwards and the module will remain 2HP wide, but will of course be a little deeper.
This way you can build your own DIY-things as add-ons on the backside of the Otto 8 Passive.
Simple passive protection
By creating a DIY-addon as described above, you could for example build your own passive protection with resistors in the signal line for each jack.
Of course you can do this even simpler by cutting a female to female dupont cable in half, then solder the resistor in the middle and isolating it with some shrink tubing.
Existing prebuilt 8x Output Buffer module
The 8x Output Buffer is a complete module that is produced by manikk. It is based on the Otto Passive Mono as a front and then we have added an add-on PCB with the electronics needed to create a 8x Active Output Buffer.