Audio I/O 1U purpose

I’ve just bought the Audio I/O 1U and I am not sure if its is not working or if it is intended to be used differently? I thought it was similar to the module WMD Pro output?
I wanted to use it to interface between my eurorack VCA ouput to my audio interface, so that the audio interface receive the pro balanced line level (+4 dBu).
So I have connected the VCA output of my eurorack to the left channel line in input and put the knob to the right and the left line output to my interface audio but it does not work. Actually none of the leds light on whether from line in or line out.

Am I using this module correctly?


Do you pairing Audio I/O with Audio I/O Jacks ?

Hi Jaewoo, no, I did not because I was not planning to use 6.5mm jacks, only 3.5mm… Is it mandatory to connect it to make it work?

I think so…someone correct me please if I am wrong…

Yes, it would be great if someone could confirm. I am thinking what is the purpose of having 6.5mm jack inputs (in the Audio I/O Jacks 1U module) in an Eurorack?

Also I’ve realised that actually what I need is probably the line out 1U alone

The line out module is a mono line out (Eurorack to line level). The Audio I/O is stereo, and has both line in (line level to Eurorack) and line out (Eurorack to line level). Your problem is that unless you have the 7U case, you also need the Jack module ( It’s a separate module because the 7U case has the jacks built into the case itself. The ‘line in’ part of your module is an output, which would amplify an external source from the corresponding 1/4 line level jacks, right now you’re plugging your Eurorack signal into it as if it was an input.

ah, great explanations DMR, thanks a lot! :slight_smile:
So you are confirming I need the audio I/O jacks module and I need to connect the two!

I am still wondering what kind of external source signals you would want to put in the line in (line level to Eurorack)? I assume you coud input a signal from another synth or any other instrument so you could pass it to some module of your Eurorack, for example a specific filter?

Exactly suntavern! This opens you up to running other signals through your system like drum machines, synthesizers our the output from your DAW.

Consider that most traditional mono synths have an audio input, to run external audio through the synth’s filter and VCA. The line in could be used in a similar way, but in a much more flexible manner since the signal path of the modular is open ended.

Thank you all, this is way more clear now :slight_smile:

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