I have a mixer that has a stereo output (a choice of rca or 3.5mm) and I want to connect this to an effects pedal. But I have a mono effects delay pedal that takes one mono input.

How would I convert the stereo from the mixer into this mono input, would I just use one of the sides of a connected stereo cable? or is there a better way?

  • after a bit more research looks like it’s called a “stereo to mono summing cable”. I asked here bc I tried to ask a bunch of employees at the music store and no one knew.
    – user34288
    Dec 29, 2019 at 0:46
  • @Foreyez- as you can tell from the answers listed, there are a number of ways to combine a stereo to mono signal, the main concern is probably phase cancelation where an improperly recorded signal will cancel itself out when combined to mono. If you're not dealing with a recorded signal, that won't be an issue. Jan 1, 2020 at 15:47

3 Answers 3


The traditional method of adding effects to your mix is to use an Aux or Effects bus, not the main outputs.

The wiring is Aux out -> effect ->Aux in. This has several benefits:

  • you can route signals to the effect independently of the main mix. E.g. you can apply the effect only to the vocals.
  • you can control the mix between original signal and processed signal from the mixer

Aux buses are often mono, so that solves your immediate problem too.


One approach to connecting two (or more) outputs to one input is to sum them, using appropriate resistors to prevent the outputs trying to override each other.

For a line level signal, this could be a 1 kilohm resistor connected from the left output to the mono input, another 1 kilohm resistor from the right output to the mono input, and the grounds simply connected together.

You would have to get an appropriate lead made up with the right connectors, with the resistors in it.

  • you think an a/b/y switch would properly sum them using resistors? for example: morleyproducts.com/aby-selector-combiner-switch
    – user34288
    Jan 1, 2020 at 2:59
  • @foreyez It looks like some do, and some just connect both inputs together. I don't know what's inside the one you gave a link to.
    – Simon B
    Jan 1, 2020 at 17:08

If it was my decision, I would simply pan the mixer channels to one side or the other and connect the output of that chosen side into the effects pedal. The mixer becomes the combining network needed to combine a stereo signal into a monophonic signal. The other unused output channel becomes useless when used this way, and exists as a spare. The output of the mixer may be inclined to overdrive the input of the effects pedal if you drive it hard, so you may need to take that into consideration. It is possible to design and build resistive networks (pads) that reduce the level of the output signal to address this problem, but you may find it isn't a problem for you. Give it a try and good luck.

Your Answer

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