@thecarpathian To acquire an answer to this inquiry, will take a little time as I am out of touch with the person who presented the Power Amp.
Plan B, I have trawled the mails of the Amp owner on their preferred forum, I am 99% sure the Link in the follow up post is the Amp I was able to be demo’d. ( I'll Post Link separately incase this post gets dumped if the link is refused).
What I do know is the Amp’s were a Punt Purchase by an individual who is a adept EE and has a lot of DIY Builds under their belt. Also the Amp was purchased to be part of OB Speaker DSP Amp assembly.
The Amp was in the owners view so impressive for the outlay, the owner wanted it to be experienced as a Monoblock for the entirety of the Frequency Range.
I also know the Amp’s in question had a couple of changes to the original schematic/topology, as a few components were swapped for parts the Amp’s owner had in their spare parts collection. I recollect talk of a change in the Power Supply Module. I also know through the discussion had, that the changes were not expensive or complex and thought of as quite simplistic.
Whilst Trawling the Amp Owners mails, I have learned the Owner is now a vociferous advocate of the Neurochrome 686 Power Amp’s, I my self can not disagree, I have very positive indelible memories from all experiences had, where these Amp designs are used.
The Amp Owner makes the statement ’World Class for Extremely Sensible Monies’. To make such a statement is of interest, as one very good friend of this person, is the owner of LDA who does make World Class Amplification.