This might help!
I couldn’t find a manual online. But after looking at some rear panel photos and based on how bridgeable stereo amps are usually designed I would expect that you should connect speaker + (probably red) to the red output terminal of channel A on the amp, and speaker - (probably black) to the red output terminal of channel B on the amp. The input to the amp would be connected to the RCA connector for channel A.
Also, of course, you would set the stereo/bridged mono switch on the rear panel to bridged mono. And note that the amp is not intended to be used in bridged mono mode with speakers having impedances of less than 8 ohms.
I owned a pair of Audionics CC-2's.........about 32 years ago! And they weren't new when I bought them! I did enjoy them at the time as they were my first foray into audiophildom.
I'm pretty sure I did not have the manuals for them and I did bridge them and use them as mono amps. I'm thinking there must have been some type of diagram, so something, on the amp that showed which terminals to use for mono. Is there anything printed on the amp showing mono hookup?
The directions regarding "connect input to channel A" is referring to your INPUT from your pre-amp. Connect the input from your pre-amp to the channel-A input on each of the two mono amps. Do not use the channel - B input on either of the amps.
You might want to try to reach out to AudiogoN user rwwear. He had a post from a few years ago saying he had a pair of CC-2's he sometimes ran in mono.
... how is circuit complete without a groundThe two black output terminals of the amp are almost certainly connected directly together within the amp, as well as to the amp’s circuit ground (to which the ground sleeves of the RCA connectors are undoubtedly also connected, by the way).
In bridged mono mode the red output terminals of the amp would both have full amplitude signals on them, with the polarity of the signal on channel B being the inverse of the polarity of the signal on channel A. The speaker won’t "know" that neither signal corresponds to the circuit ground of the amp. And the current supplied by each channel of the amp through the red terminal of that channel would be returned to the red terminal of the other channel, and from there through the output stage of that channel to the amp’s circuit ground.
From the perspective of each amplifier channel, a given output voltage will result in it having to supply twice as much current as it would have to supply under the same conditions in stereo mode, as a result the other channel of the amp supplying an equal and opposite voltage to the other terminal of the speaker. In effect the doubled current for a given output voltage results in each channel of the amp "seeing" the speaker’s impedance divided by two, which is why the amp is not intended to be used in bridged mono mode with speakers having less than an 8 ohm nominal impedance.