Voltage attenuator (2HP)
Jacks and potentiometers to taste.
Attenuators tend to be the first thing to go when I (re)design a module, so I keep a few of these around at all times. Completely passive design with a small footprint.
The three stages are normalled to each other, so if nothing is patched into the second input that stage can be used for finer control over whatever is left from the first stage (and so forth). Can also be used as a small passive multiple in a pinch.