I have a drum machine that gives out separate outputs for each one of its 11 sounds. I've found that I don't really need 11 outputs and some of these can be grouped, e.g one signal that has the low/mid/high toms. So I was looking for a device that would take in multiple mono TS/TRS inputs and give one output that's the summation of these inputs. I had assumed that this will be a simple cheap device - a voltage adder basically - however, such a thing doesn't seem to exist so I may be missing some understanding here.

So my questions is if this can be done, then what are the options? Using an audio interface/mixer and outputting the mix signal is an option of course, but the whole point of this is to mix the signal before it reaches the interface.

If this is not as simple as it sounds which explains why there is no such device around, then could you explain why?


  • 4
    What drum machine is it? Commented Jan 1, 2022 at 20:23
  • @topomorto It's an RD-8 (808 clone).
    – Paghillect
    Commented Jan 2, 2022 at 7:15

1 Answer 1


What you want to do is to mix signals, so you need a mixer.

Perhaps the cheapest and simplest commercial device to do the task could be a passive mixer. Note that passive mixer will reduce the signal volume so you will need to compensate for this either by increasing the output volume for the mixed channels on the drum machine, or input gain on your main mixer.

If you're into electronics and soldering, you could try to make one yourself, see e.g. this simple diagram:

enter image description here


Alternatively, there are also simple and cheap active mixers in the market.

  • 1
    I actually managed to find a few simple mixers on Amazon for ~$30 but building one could also be a fun weekend project. I'm assuming the averaging of the gain would result in some loss of quality, but that shouldn't be a problem from drum sounds.
    – Paghillect
    Commented Jan 2, 2022 at 7:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.