We have many customers that say their ML speakers sound best with McIntosh amps. This is after they have used various other brand-x amps. McIntosh amps certainly can power low impedance loads and have been doing so for many decades. Thanks,Ron-C
Ron, you are quite right of course; but while you were at it, why didn't you tell the people
why this is so? Are Mac tube amps great tube amps? Sure, but that alone is not the REAL reason for their success with the
relatively small lo-Z portion of (some) electrostatics' impedance curves.
So, the real reason? To paraphrase a former President, "It's the Unity Coupled Circuit, stupid!" This ONE THING
uniquely qualifies McIntosh tube amps, among all the tube amps in tube-ampdom, to drive stats with complete ease and aplomb -- BECAUSE -- as Mr. Ron Evans will I'm sure confirm, the UCC is a
current-controlled circuit. All other conventional push-pull tube amp circuits are
voltage-controlled.
Now, Frank McIntosh came up with the UCC to achieve lower distortion figures, not to drive electrostats. He was no doubt
aware of electrostats since they were being developed at Bell Labs while he was employed there. And from what I've read, they sounded excellent compared to other speaker designs of the time. Unfortunately, the idea had to be discarded because the diaphragm was made of bovine intestinal membrane, and it began to smell bad after a few days -- (and if you think I'm blowing smoke, look it up!)
Today when connected to a Mcintosh tube amplifier, the (capacitive reactance) electrostat "looks back" through the bifilar output transformer and sees: current! If the amp were anything but a Mac, it would see voltage -- not exactly optimum for a stat, certainly
not like a McIntosh!
I've had my electrostats now for over 20 years, and have driven them with some excellent amps, including ARC (tube) and Mark Levinson (ss) so I
really do know what to expect, honest! And when I decided to sell the Levinson and finally go with a tube amp again, I did some
serious research which included speaking to the manufacturers themselves, and asking a lot of technical questions. The bottom line was that only a McIntosh tube amp had the design chops to be able to
grab an electrostat, the way say a Krell can
grab a woofer :yes:
I will allow there is a certain rationale for using a solid state amp with the older model hybrid electrostats which require the amp drive a woofer section along with the stat panel. But something is lost either way, unless of course you bi-amp. And I've done
that too :yes: even though my "woofer" was a pair of Wilson Puppies! But jeeeez, so much gear!
Finally, MartinLogan, and some others I've noticed, have come to their senses and stopped chasing the "full-range electrostat" grail. (For that, there is Soundlab, and even they work quite nicely with Mac tube amps, thank you very much!) For the rest of us, MartinLogan now (finally) supplies their "hybrids" with (essentially) a built-in, self-powered subwoofer. This frees the owner to choose the
best amp for the panel, and that's all I'm going to say about
that!
from that little technical school on the Charles River :thmbsp:
