Hello Bigtwin,
I’m driving A645 with Atma Sphere MA-1 tube mono blocs, 2 x 140W, OTL. I have also a matching Atma Sphere MP-1 preamplifier. Previously I have owned all Quad speakers and a couple of other ESL including big Stax ELS speakers.
Congratulations on your purchase of Majestics. You have just purchased a pair of the very best speakers ever made on this planet.
While many owners of SL drive these speakers with Parasound, Krell, Pass Lab and other SS amplifiers, in my humble opinion electrostatic speakers will work best with OTL tube amplifiers. The best match for your SL is actualy Atma Sphere MA-2 (which is quite expensive), but MA-1 model will work as good.
There are several technical reasons why OTL amplifires work so nicely with electrostatics but I will not enter into this subject.
To properly setup this system you will need to replace small tubes delivered with your amplifier (ans preamplifier). Old NOS tubes sound much better. Good power cords are very important. Good XLR cables are also VERY important contrarly to what says the notice, power regenerator is mandatory in all circumstances, as well as heavy room treatement. You need time and patience. Each system optimisation and upgrade will reward you with huge improvements in sound. I’m talking from my first hand experience.
Feel free to coontact me for more details.