Used: ~$1100 (depending on condition, pro/home, mounting plate size, and age/remaining warranty)
250WPC RMS @ 8 Ohms, 400WPC @ 4 Ohms, 800 Bridged @ 8 Ohms
SoundStage Review: CLICKY
I'm surprised that nobody has added this amp to the list. While not considered by many to be in the rarified air of top-tier high-end amps such as Jadis, Pass or Krell, my experience has been entirely positive. I first noticed a substantial improvement when this amp replaced an SAE A202 which was powering my Dahlquist DQ10's. There was an obvious improvement in holography and tonality. Instruments are more 'articulate', staging became both higher and deeper.
And then came the reQuests to replace the Dahlquists. I ran 'em both just to experiment a bit, and can say for an absolute certainty that the Bryston never skipped a beat on either of these very demanding loads. One thing about the Bryston line is that they're quite 'transparent' and any shortcomings you have elsewhere in the chain are revealed. That's why I went from a McIntosh C28 Preamp to a Krell KRC-3.
If you're looking for an amp that won't run out of steam, without having to donate a kidney, the 4B-ST is a bargain.
I second your 4B ST recommendation on ML ESLs or for that matter any speaker out there. The amplifier is absolutely revealing and bullet proof, have had mine for over 15 years powering Martin Logan speakers. If fact Martin Logan use Bryston amps as reference amplifiers in speaker development phases. Also note using the Bryston BP25 preamp, with balanced XLRs between preamp and amp, bit acquired at same time. In the years hence, no other hi-end brand has been able to top them, some equal at more than twice or more multiples of the cost.
After a good deal of researching and auditioning, looking to add the Bryston BDA-3 DAC. The entire combination works so well that, it is very difficult for others (KRELL, Chord, Mark Levinson, Cary, etc.) to top. Very satisfied listener, not too mention the time and dollars saved not playing the "product of the month club". Happy listening.
And the lexicon rebranded models as well. I've got a Lexicon 312 for my Montis and StageX and a 212 for the EFX in back. Love them.