'Turntable Switch'

I built this device to allow me to integrate a turntable into my workshop amplifier.

As the main DAC output is already attenuated, and the amp runs at full power, the turntable input needs to be attenuated as well.

So I built this box, a dual input switch, with one of the source's inputs attenuated with a gain control.

Inputs and outputs are on TRS plugs.
Switching uses one Grayhill rotary mini-switch.