Amp Upgrade time, $6000 budget, used or new.

Pass Labs, best you can find for the $. Decent resale too.

Buy a used Mccormack dna-1 or dna-.5 and have SMC audio (Steve McCormack) upgrade it.  I had him do a dna-.5 and ended up selling my parasound jc-1 monoblocks.  Total cost (including purchase if the dna-.5) of about $3k and competes with amps much more expensive

Wow, 6K, there’s an ocean of amps out there!

If it were me, I would seriously look at the Sanders Magtech ,
will drive ANYTHING, and is reliable, is class A/AB, lifetime warranty........DID I MENTION LIFETIME WARRANTY.

Roger Sanders is a genius, and the Magtech is ALL the amp you will ever need!!”!

plus a 30 day free trial.

www.sanderssound.com.
Seriously look into it. You will,Not be disappointed!!!

enjoy.

the Magtech is made just for magnepan and electrostatic speakers which need gobs of current.

 If I were you I would look into the Sanders Magtech!!”!

their amazing,and stable to 1Ohm or less.

I should mention That I don’t tend to listen loud and I love soundstage and ambiance. I like to put on an album after getting my ass kicked all day at work and just float away..... makes me think tubes????? But, I like incredible detail and pinpoint soundstage with height and depth, so I basically just want as close to perfect as I can get for my budget. Who doesn’t? 

https://www.ebay.com/itm/KRELL-FPB-450MCX-MONO-BLOCK-AMPLIFIER-PAIR-IN-THE-EXCELLENT-WORKING-CONDITIONS-/193437966918?_trksid=p2385738.m4383.l4275.c10

How about Krell Fpb 450 monoblocks?

It will drive your speaker aplomb.

I had used Krell KSA 150 to drive Apogee Duetta Sig from 1989 to 1999.

Thomas