tube amps and electrostatics

I do not have experience with your amp, but I run my Martin-Logan Aerius i speakers with tubes by choice. I use 130W monoblocks and they made the Plinius SA250 (and several solid state others even more so) sound sick. A well constructed tube amp can sound much more lively than solid state amps provided you do not push them too hard. Friends with more experience of Martin-Logans believe tubes are preferable. If you are thinking of spending $2,500 on electrostatics then your musical tastes do probably not include playing drum and bass at 120dB, right? So what you lose by not using solid state will not be very important. If you are buying an electrostatic its probably because you want the transparency, purity, grainlessness, lack of cabinet resonance etc that the electrostatic can offer. Why spoil this with the electronic nature of solid state sound? You will probably just love the sound of your tubes when you hear them through some 'stats (preferably a hybrid for reasons stated in previous posts). The only problems you might encounter will occur because you want to play them louder than your amps can deliver. Try it.

ESL 63 and US monitors have an intentionally benign impedance curve that is nominally 8 ohms an is rather flat compared to other electrostats. The lower the output impedance of the amp, the better.

Sound lab speakers have chosen Wolcott amps to drive their speakers. these amps can handle the most difficult load

Yes yes yes tubes love stats ,,,, I have jolida mono blocks w/ my Martin Logan's clsiiz !,,,

Something like 80% of our MA-2 amplifier production has been for Sound Lab owners.

The Quad ESl 63 as been a good match for our M-60 and MA-1 amplifiers. Martin-Logans (which have a lower impedance) usually require a set of ZEROs (http://www.zeroimpedance.com) to work with many tube amps. The CLS-1 is an exception- its impedance was set higher and so is easier for tubes (M-L really wants their stuff to work with transistors, so even though they sound better with tubes, their impedance is usually set lower so transistors will have an easier time with them).

Some of the old Accoustats were an easy load for tubes and some were not, as Accoustat was trying to crack the solid state market too. If one of the higher impedance Accoustats, IME 50-60 tube watts is plenty of power.

The fact of the matter though is that the nature of tubes where they do not always act like a voltage source (which is the ability to double power as impedance is cut in half) is an advantage when trying to drive the higher impedances that an ESL often has. Unlike a box speaker where the high impedance in the bass can be the result of a box resonance, the high impedance of an ESL has nothing to do with resonance and so they still need power to drive them even though the impedance is high. Tube amps do this better than transistors.

As an example, a 600-watt transistor amp can't make any more power into a set of Sound Labs than you might get from a 150 watt tube amp. Put another way, a lower powered tube amp can often make as much or more power than a more powerful transistor amp when driving ESLs.

In short, ESLs and tubes have been one of the better combinations in audio for the last 55 years.