It can control volume for Balanced and Unbalanced signal monitor.
It has an output selector so you can choose between two set of monitor.
Also it has a mute switch to mute the output.
Technically this is a balanced attenuator pad, so it as a minimum reduction gain, which for the proposed schematic is -1.58dB.
A design like this can result in a high frequency loss for long output cables (>15mt).
As you can see, it's just need a logarithmic 10k dual pot, and a 4 1/4w 1k resistors, metal film 1% resistors are better, but you can use even carbon film 5% one without any audible issue.
- read risk disclaimer
- excuse my bad english