Bridgman , do you have the Yamaha 801? If yes, what’s your personal opinion on it?
I don't have one, although I have a nagging feeling that one of my friends had one of its predecessors and was very happy with it.
If I believed in electronics from different vendors having different "sounds" I would put Yamaha in the "brighter" category and so maybe not the best match for your M60's, but to this day I don't know if I believe that. My experience with Yamaha electronics has mostly been paired with Yamaha speakers, and while I do believe the speakers have characteristic sounds I have a tough time extending that to electronics.
All that said, it's not clear to me that the Yamaha integrated amp would get you much benefit over the RX 595 you have today.
For what it's worth, my stereo electronics progression was:
SWTPC pre-amp with SWTPC power amp (yeah, 40 yrs ago)
Advent receiver with SWTPC power amp
Advent receiver with Marantz power amp
Advent receiver (I got domesticated and downsized)
HK 3470 receiver
HK 3470 receiver with Adcom GFA 555 II
TubeDAC with Adcom GFA 555 II
TubeDAC with 2x ADA 1500 (hope to finish setup this weekend)
I ended up not using the tube stage, but did find that using the optical out from my old Kenwood CD carousel via TubeDAC significantly improved imaging compared with the RCA outs and internal-to-carousel DAC I was using previously.
Just noticed your notes about testing positions etc..., so a few more comments:
#1 - agree that even the older Axioms are not what I would call "bright"... but what they do seem to be is flat in the 2-3 KHz range where many other speakers have a slight dip (sometimes referred to as "the BBC dip". There are some recordings floating around that seem to have been optimized for speakers with a 2-3 KHz dip (eg the studio monitors had it) and those seem to be the ones most likely to be responsible for the "bright" label.
The upside of the flat response is the very nice open-ness / crispness / transparency / whatever that you are probably enjoying right now.
#2 - the closest thing to a quirk that the bigger Axioms have is that they usually work best a few feet out from the wall, although port plugs can sometimes help there. If you have the options for placement the one with the longer listener-to-speaker distance is probably worth trying first.
