OTL amplifier and electrostatic loudspeakers

Ralph @atmasphere on this board should be ultimate authority @gdnrbob so rightly said

I would try it with and without a set of ZEROs (www.zeroimpedqance.com).
With that speaker our customers seem to like both with and without. Overall the speaker does not have any severe impedance dips, so if you use a set of ZEROs don't use more than 2x.
The ZEROs would mostly be used to restore the highs - the amps otherwise should be fine in the bass. Make sure the speaker is at least five feet from the wall behind them.

@OP. 
Well, there you go...
B

one reason why I appreciate manufacurer presence and expertise here :-)

@tomic601 , as we both own Vandy's. I concur. A great manufacturer stands by their product. Considering that I bought my 3a sigs used, Mr. V. called me back the next day, and even the following day to see if I still had a problem. Now that is exceptional service.

Do you have Atmasphere's?
B