Test and measurement: Dummy load for audio power measurements

I built this in a hurry as I needed to make some quick measurements.
It's not the tidiest, but it's functional.
There is an internal voltage divider which fixes both RCA and BNC outputs at 10:1 for a safe voltage reduction.
The 3 position rotary switch has the following 3 positions: Off, monitor 8 ohms, monitor 4 ohms.
The grounds of both channels are common and also connected to the grounds of the RCA & BNC connectors, so this has to be kept in mind when testing, that the amp under test is happy to have the (-) of the speaker grounded.
This also rules out testing Class D amps unless particular attention is paid to the grounding.