Stereo Ins & Outs: Are You Properly Connected?

Neunaber Inspire

So, you have a stereo pedal and a mono signal. Does it matter which channel you plug into? What if you have a mono input and stereo output? Or a stereo signal that you want summed to one output? Or, maybe you're simply wondering which channel is "left" vs. "right." Well, you're in the right place, because I have the answer for you.

Different brands handle input/output configuration differently, so this information only applies to Neunaber stereo pedals. If you have questions about a different brand's device, it's worth following up with them. Not everyone does things the same way.

1 = One & 2 = Two

With most of our stereo pedals, we label the channels "1" and "2." Here's what this means:

  • "1" is for a single signal (mono) or for the first of your two stereo signals.
  • "2" is for your second stereo signal or for a TRS stereo connection.

In addition, you can connect a mono input with stereo outputs. The mono signal is duplicated and processed to create a stereo output. Or, you may connect stereo inputs and a single output, where the single output is a sum of the stereo output signals.

This diagram shows the various ways our stereo pedals can be connected:

Left vs. Right

If you have "left" and "right" connections, then you can use either "1" or "2." It doesn't matter if you switch them around, as long as you are consistent. For example, if you use channel 1 as "right," then use this consistently throughout the signal chain.

Dos and Don'ts


  • Use only input/output 1 for a mono connection
  • Use only input/output 2 for a TRS stereo connection
  • Feel free to use different connections for input & output. They are independent.


  • Use input/output 2 with a mono connection. It must remain unconnected.
  • Use input/output 1 with a TRS stereo connection. It must remain unconnected.


This labeling scheme applies to most of our pedals. The only exception (at the time of writing this blog) is Iconoclast, which has TRS balanced — not TRS stereo — outputs and does not support a mono-summed output. So, we decided to label its connections differently. Please refer to the Iconoclast User Guide for more information about how to connect this pedal.

(Originally posted by Brian Neunaber 7/15/2021)