Possibly the most esoteric purchase I’ve ever made. I spent the best part of a year tracking these down and in a very short space of time found two sources (that might have been one source but anyway!)
They are one of the most recent through hole pcb versions of the “Super Symmetry” Dynalo amplifier with Golden Reference psu by Kevin Gilmore. There is a more recent design using smb parts but that was even harder to find and of less interest to me. Given some of the small details of the full set of pcbs and matched transistors I have a high confidence that this is a genuine set from a group buy which was what I was after, rather than a clone.
For anyone who is saying “eh wtf does that all have to do with anything?”: Kevin Gilmore’s designs are widely seen as being extremely interesting and high quality. The HeadAmp GS-X Mini is a based on this amp and psu. The original design is a good twenty years old at this point but has been steadily revised up until fairly recently. The Dynalo is a low impedance, fully balanced amplifier and this edition is a version revised to make use of ideas by Nelson Pass about the design of balanced amplifiers, known as “Super Symmetry”.
That is almost certainly enough audio nerdery for one post but I have more if anyone really wants it. 