I decided to build a passive preamp for use with testing amplifier designs, especially those with no preamp stage of their own. It’s a simple circuit but it serves its purpose well.
The schematic is shown below.
There is a great article on potentiometers here, here, and here. I chose a 10k Alps dual-gang audio taper (log law) potentiometer for the attenuator and a simple hammond case. The case is a Hammond 1455n1201 and is available at DigiKey.