Rocray, what I was envisioning in my previous post is that the signal on pin 2 of the XLR connector goes to one channel of the amp; the signal on pin 3 of the XLR connector goes to the other channel; and the ground pin (pin 1 of the XLR connector) goes to the ground of both channels.
If the XLR connector is then provided with a balanced pair of signals for one channel that configuration would be a means by which the amp could provide bridged mono operation without the need for an internal inverter stage. A single speaker would be connected to the + output terminals of the amp, and the - output terminals would be left unconnected, as I indicated in my first post in the thread.
However if a y-adapter were used to connect left and right RCA outputs of a preamp to that XLR connector the result would be that the signal from the preamp for one channel would be routed to pin 2 of the XLR connector and from there into the signal path of one channel of the amp, and the signal from the preamp for the other channel would be routed to pin 3 of the XLR connector, and from there into the signal path of the other channel of the amp. And the circuit ground of the preamp would be routed to both channels of the amp.
In that situation connecting one speaker to the + and - output terminals of the amp for one channel, and another speaker to the + and - output terminals of the amp for the other channel, would result in normal stereo operation.
Regards,
-- Al
