which is better amp for electrostat speakers

Can't comment on those, but everybody I know running stats prefers Wolcott Presence 220.

The Wolcott Presence 220 may be a good match for electrostats, but so are the Monarchy Audio SE-160 monoblocks, a tube-hybrid design at less than half the price of the Wolcott. I haven't heard the Wolcott amp, but I doubt that it sounds better than the Monarchys. I used mine to drive InnerSound Eros speakers and I know that C.C. Poon, Monarchy's designer uses Sound Lab speakers.

I have also used the InnerSound ESL amp (both versions), and to my ears, the Monarchy units were preferred for their warmer balance and less fatiguing high frequency performance. I've never heard the Spectron Musician II, but before I bought one to drive stats, I'd want to know how stable it was driving such a difficult load. I've heard some otherwise great-sounding amps perform miserably when hooked up to the InnerSound speakers... so it's not something that one can take for granted.

you definitely want to consider tubes with electrostats.

I am currently using Innersound Eros Mk II (active) with an Audio Research VT100 Mk II. It sounds good, but I recently heard these speakers driven by Manley Neo-Classic 250 monobloc amps. I must say the sound was "awesome". I strongly recommend you listen to the Manleys as well as the Wolcotts.

Some time ago a friend brought over his Spectron Musician I to try with the Sound Lab U-1s. It did well, although I preferred my tube amps over it. Since then I have replaced those amps.

The Innersound amplifier is designed to drive ESLs, obviously optimized for their own speakers but very capable of driving Sound Labs and other ESLs well. For this reason I would suggest auditioning the Innersound.

Brian Walsh
Essential Audio
Barrington, Illinois