Using tube amp with electrostatic speakers.


Moons ago I started similar discussions and thought I had been given enough good advice not to approach the subject again. Here goes anyway. I've used Martin Logan electrostats for well over 30 years with quite a few different amps but have recently switched to a tube amp and dynamic speakers with which I am very satisfied.  It consists of the Cary Rocket 88R amp and Serie Reference 3 speakers. 

My brother was visiting last week and was so impressed with the sound that he decided that he might want to try a tube amp also (probably the same one as mine).  However, he is using a pair of SL3's that I gave him years ago and I'm concerned primarily about the current requirements of the Martin Logans as well as other concerns that I'm not thinking of.  I don't want him spending money on something that may not bring him improved sound so would appreciate more advice to pass on to him.  He currently uses a Rogue Audio SS amp with his SL3 speakers and, to me, it sounds very good. 
jimbreit
If one can bi-amp Maggies (or any other magnetic-planar speaker), solid state on bottom and tubes on top is a killer combo. It's the bass drivers that suck up all the current.
bdp24 ...

In an earlier post, I mentioned that I used a pair of "loaner" Atmosphere 60 watt mono amps for a couple of years to drive the Acoustat Four's I used to own. Then I switched to an ARC Classic 60.  The ARC produced better base, the Atmosphere took the honors in the mid-range. Both amps were under powered for the Acoustats. 

On night a friend brought over two of Frank Van Alstine's 250 watt solid state amps with one of Van Alstine's bridging devises. We used high quality IC's to hook everything up.  

We sat in total amazement when those hundreds of watts started driving those huge electrostatic panels. At the time, the room size was about 25 x 40 ... and the room was totally filled with non-distorted sound. No matter how high I cranked the volume control, the speakers and amps went right along with the program.  Haven't heard anything like it ever since. I have to admit, I sometimes pine for that system. 
Damn oregonpapa, that is a BIG room! In the 80's I heard the Acoustat 1+1, 2+2, Three, and Four driven by ARC (D-75 and D-150), but they can use all the power they can get. Same with Maggies, of course.  I'll be setting up a pair of Tympani T-IV's soon, and have an only 200w/ch amp for them, a PS Audio. There are guys throwing 2000 watts into them! But the room is pretty small, so hopefully 200 will be enough for the bass panels. They will be bi-amped, with either a tube or SS 100 watter on top.
Stewart,  I apologize for the tone of my remarks; I was feeling playful, and perhaps that came across as hostility, which was not my intent.  It seems impossible to get my point across to the assemblage, which is simply to re-state that one should make one's own decision on amplifier power and type based on the electrical characteristics of the speaker. Period.  There is no one correct answer that fits all situations. Of course, this goes for any type of speaker.  Sadly, most modern day ESLs are difficult loads for tube amplifiers, not because of the operating principle of an ESL per se but because of crossover design.  Martin-Logan is chief among the guilty.  But they really don't care; they assume you will buy the latest solid state behemoth to drive their speakers.  Try a Quad 57 or a KLH 9 sometime (both nominal 16-ohm loads), and you will know what I'm talking about.

And, since you brought up magnetic/planar speakers, others are now starting to discuss them as if there is any parallel with ESLs.  Apart from size and shape, there is not.  To run a magnepan with a tube amplifier, one should consider using the Zero autoformers.  I used to use Zeros with my Sound Labs, until I got some advice on how to "fix" their fundamental impedance characteristic.
Electrostatics love current .much more then Voltage as with a Tube amp.
put a Pass Labs 250.5 , Big Krell, or  Coda  amplifier and you will get tighter bass ,better dynamics and control
as well as speed. Even Maggie love power,Soundlabs for sure.