$6000 Budget Which used Amp ?

I hope this helps. I read that ML Electrostatics with a Audio Research VT100Mkll or Mklll will make you think you are in Audio Heaven, However I have run the Krell FPB250 with the same speakers and it was just AMAZING really Wonderful. As you know the Krell FPB250Mc are SolidState and Audio Research are Tubes. I would think the ML Speakers would really Shine with tubes more so than Solid State

Mp is right. Give your Logans a listen with both solid state and high powered tube amps and hear the difference for yourself. They really open up with tubes. Tube amps are also better able to deal with the sometimes interesting impedance swings that these speakers can produce.

By the way, you didn't mention which Martin Logan speakers you plan on using. Are you driving Statements, Prodigy's, CLS's, etc. -- it will make a difference in recommendations although conceptually I think tubes, (or a combination of tubes and solid state), are still the way to go whatever the model.

Go listen for yourself.Take amps home to listen.

My Quest Z's sound great with my BATVK500, much smoother than with my Classe. I'd suggest a tube preamp and transistor amp, BATVK30 and VK500 are great in my setup. I've stayed away from tube amps, mostly due to the cost of changing tubes. I leave my stuff on all the time, tubes would need replacing fairly often and output tubes aren't cheap.

How about Sonic Frontiers Power 3? I was looking at both the VT200 and the Power 3. I found the Power 3 with a 5-year warranty here on Audiogon (Underwood Wally 770-667-5633, great guy) for a lot less than the VT200 used. The sound is very good with my B&W 801s.