Responses from whitecap

That Transformational piece of Gear We All Wish For
@ronkent:  its the original REX (circa 2008, I think), with all new tubes specified by BAT.    Amp is the BAT VK-655se, which is a fabulous beast, best amp I have owned.  Upgrading to the REX 2 is a possibility for us in future, or REX 3, but for ... 
Keep McIntosh C2500 pre-amp or upgrade to C12000?
@meadski:  NOS Telefunken 12AX7, recommended and purchased from Kevin at Upscale.   Made a night and day improvement to the C2500.    
Keep McIntosh C2500 pre-amp or upgrade to C12000?
Agree with @glennewick: swap in some NOS tubes to the C2500.   Telefunken in our C2500 was a major game changer.  Major.  If not, I would have sold that Mac a long time ago.    
That Transformational piece of Gear We All Wish For
Nice to see all the well deserved praise for BAT.   I was hesitant to add my 2cents here, but it is on point.   The VK80 is terrific for sure, we had one for about a year.  But the REX was one of those transformational changes that we all hope for... 
Help me understand the current amp market
@jyaki:  We too listen LOUD a lot, I'm talking concert-level loud.   Having tried both tube and solid state pre-amps, we now only use tube pre-amps, with solid state amplifier(s).   And, FWIW, we have also resigned ourselves that the best pre/amp ... 
Great Interview-
Years ago we saw Bonamassa in NYC several times, but surprisingly the sound at his concerts was was at best, fair.  So I bought several of his CDs to play on my rig hoping for better.  Didn't happen.  The sound Bonamassa's CDs is so bad, I literal... 
How would you spend my next $5K?
Yet another recommendation here for a second 812 sub.  You're missing half the fun.    
Tubes Recommendation for McIntosh Preamp
Also, FWIW, on a C2500 I swapped in NOS Telefunken 12AX7.   Huge  improvement across the spectrum.      
REL Hum. Stumped
Alas, I too have the hum with my pair of S/812s.  Amplifier is pure balanced, BAT VK655se, which apparently presents its own unique issues with the Rel Speakon.   @last_lemming  I am completely ignorant of technology, so I'll never be able to rep... 
Qobuz hell
Qobuz "customer service" in one word: awful.     
Are your listening levels healthy? Doing damage?
No.  Probably.  And have the same pattern as @markalarsen.    
Finding a Power Amplifier for Luxman C-900U
My understanding is Magico has use Luxman in several of their high-end audio show set ups, as the two are reputed to make magic together (pun intended).  So I would also suggest trying the m900u.  I currently use the c900u with a pair of m900u (in... 
Ditching Class A Amps due to Heat - Sort of a Poll
No, no, and no.    
Magico S3 mkII
@rman9, belay that request.  I see you have answered my question thoroughly in other threads.  Thx.  
Magico S3 mkII
@rman9:  Curious to hear your opinions on the MC462 vs the Luxman?