If you are looking to monostrap a tube amplifier, the procedure is different from that of a transistor amp.
This procedure is outlined in the Dynaco Stereo 70 manual FWIW.
The amps to be monostrapped must be absolutely identical! The same signal must be fed to their inputs. A Y adaptor can be used. Essentially, the outputs of the amps are to be paralleled. This will cut the output impedance in half, so if you have an 8 ohm tap on the output transformers, they will be driving a 4-ohm load.
Some amps have a grounded 4-ohm tap so the accommodation is slightly different, but in general you are safe if you have a jumper between the minus terminals of the two amps and the highest tap available, as well as the taps that are being employed.
Obviously this hookup can really mess with things (destroy valuable parts) if not done correctly!
In our case our amps are OTLs and have no output transformer, but the same technique is used. Note that in some cases it may be more difficult to obtain correct bias readings on the power tubes unless the amps are separated.
The output power will be doubled and the amplifier will be able to drive impedances that are half of what they were before.
If you try to do this with transistor amps you can expect to damage them- this only applies to tube amps.
