Great new format!
Here is a picture of a pair of PP GM-70 monoblocks built by Fernando Rodriguez from my design. The second one was powered up the first time yesterday and is now burning-in with some delightful Joaquin Rodrigo concertos playing.
The design is transformer input phase splitting, 6SN7GT diff pair choke loaded direct coupled to diff pair 6BX7GT IT loaded driving a series transformer loaded GM-70 pair. All stages are forced to operate Class A1 with current sinks in the common cathodes. It does about 40 watts with an 840v B+.
