There must be a significant dc and ac output resistance to get away with shorting the outputs together without sharing resistors
I once read that the Musical Fidelity MA50, mono power amp with 50W nominal output, was 2 MF A1 power amps, 25W each side, paralleled together.
In one of posts above Arkless says he would only expect a 10% rise in power output with 2 channels working in parallel.
What I have failed to understand correctly?
... but the right channel now has a crackle on the volume pot.