"jim" wrote

I've seen this in done in a few '60s schematics and 'Glass Audio'
articles.
How do you get the ultimate out of as few valves as possible ??
Global NFB reduces distortion but decreases gain.. Add PFB at the
OP valve
drivers. You get the gain back and the global NFB keeps the
distortion
low...

You balance one against the other...

Theory says it works. Reality says it's unstable and
unpredictable.


The quad 2 uses local +ve fb to one half of the floating paraphase
splitter, and -ve to the other half, and -ve overall. It's British.
Must be a good thing.

cheers, Ian