Too good to be true?

Al, there are two videos filmed at the BAF viewable on You Tube, from two different years. Roger Modjeski’s 90 minute (iirc) talk on tubes and tube circuits is also well worth your time.

 

Many thanks for your suggestions, advice and comments!

 

Here’s a new wrinkle – What about the Pass Labs XA30.8?  Since the woofers in my ML 11As are internally powered, what, if any, benefits would this amplifier offer over the XA25? 

For what it may or may not be worth, I have been powering ML Montis with Pass INT-150 for a few years now.  Never any issues, sounds marvelous.  No plans to change anything any time soon.

As an10490413 mentioned above, he has powered woofers.  I would like to ask if the quality of the amp makes any difference in the sound the powered woofers put out, or is it more like using line levels out from a preamp to a subwoofer?

@Jetter, Figure 1 of Stereophile's measurements of the Martin Logan 15A, which appears to be a fairly similar big brother of the OP's 11A, shows that even though the crossover point between the powered woofer section and the electrostatic panel is specified as being at 300 Hz, the panel is still putting out significant energy at deep bass frequencies.  For example, based on a near-field measurement the panel is only down about 8 db at 80 Hz.  So that would seem to be one reason to expect the amp to make a difference in the deep bass region.

@an10490413, I have no experience with the XA30.8, and it is a different animal than the XA25 in various respects, so I can't address your question about it.

Regards,
-- Al