If your $4000 budget refers to your actual budget, and not to the MSRP of the amp, then you could consider either the Ayre (already mentioned) or a pair of Bryston 7B-ST monoblocks. These two amps have somewhat different "sounds", but both offer excellent performance and are fine values.
$4000 to spend on a SS power amp - help me choose
Audiomeca Mephisto II CD Player
Emotive Audio Sira preamp
VMPS Super Tower R / SRE (ribbon tweets; ribbon mid panel)
Acoustic Zen cables everywhere
I own a Graaf GM 200 OTL as my first amp; the SS will be
a back-up or possibly drive the bass in a bi-amp situation w/
the Graaf & a VMPS active crossover.
Emotive Audio Sira preamp
VMPS Super Tower R / SRE (ribbon tweets; ribbon mid panel)
Acoustic Zen cables everywhere
I own a Graaf GM 200 OTL as my first amp; the SS will be
a back-up or possibly drive the bass in a bi-amp situation w/
the Graaf & a VMPS active crossover.