Electrostatics

[gmartan]

I take a different view of this. I've had ML Montis for 18 months now. Initially I ran them with a D200. I found the top end really scratchy and the sound generally rather thin: a lot of recordings were simply painful to listen to. I thought the problem might be a lack of power: MLs are known to respond well to very powerful amps, as the impedance is shockingly low at high frequencies.

So I got a D200 Companion on loan, thinking the D400 would do the job. There was no real improvement. At the same time I got a Sanders Magtech on demo. It's a 500W Class A/B power amp that's designed specifically to drive electrostatics. (Sturdy power supply and twenty output stages, which deliver the voltage that ESLs crave.) I found the Magtech superior to the D400 in every way: smoother top end, flatter FR, more holographic soundstage. I bought the Magtech to drive the Montis.

I totally agree with your experience.  I found the D200 just as you did with my Summits.  Conversely, they were really amazing with a pair of small dynamic speakers I tried. Huge sound-stage and great bass.

The current line of Martin Logan speakers all go down to 0.6 ohms so output transformer equipped amps will roll off the top end, and sound dull, since the impedance can't be properly matched.  Oddly, even though the woofers are powered, a big solid state direct coupled amp has the best control over the bottom end.  Lastly, the speakers are ruthlessly revealing of all the gear in front plus any less-than-excellent recordings, CDs in particular.  The only cure I found, while wasting many thousands of dollars in the process, is a good neutral sounding tube pre-amplifier.  What is fronting your Magtech?