Best tube amp for electrostatic speakers


For over 35 years I've almost exclusively used either ribbons or electrostats with solid state amplification and have been generally happy with the sound. Over the last several years, though, my hearing has become somewhat degraded and more sensitive to certain frequencies. The frequencies which seem to cause the most discomfort occur in the 1400 to 1900Hz range and come across as "bright" to my hearing. After researching this matter and having been given some expert advice, I've decided to pursue the idea of replacing my present amplification equipment with tube based gear.

The purpose of this post, then, is to solicit advice regarding the best approach to making this decision based on the following information: the current basic equipment is Shanling Solid state CD player, Peachtree Audio Nova used as preamp, two DBX 1531 EQ's to help compensate for age related hearing loss, Peachtree 220 amp, Silversonic T114 cable and Martin Logan Ethos speakers.

The listening area is our living room measuring 15 by 22 feet with my listening position 16 feet from the plane of the 2 speakers which are positioned 11 feet apart measured center to center. Located between the 2 speakers is an entertainment center which is about 9 feet wide. My listening interests are varied from solo guitar and light jazz to occasional orchestral music. I don't generally listen at high volumes and am not particularly interested in strong bass except for the rare action movie background.

Unless not advisable for some reason, I would like to keep the Peachtree Nova as a preamp because of the significant latitude for source connection and what seems to have a decent internal DAC. If this option would substantially defeat the purpose of the intended modification I would work around it. I can no longer deal with sounds that are "bright" which I now find uncomfortable but detailed sound is very important.

So, the questions are: is the move to tubes the best option and, if so, what might be some reasonably priced amps that could accomplish the goal. This, of course, would take into consideration room size, etc. for determining power requirements. If there are other more practical and less expensive options to consider, I would appreciate that advice as well.
128x128broadstone
Hi Bifwyne even the Magico S-5s are a hard load, just because they are a quite flat impedance, they are still 2ohms 50hz-80hz and then 3ohms 7khz-20khz.
But this isn't the only reason that them a heavy load.
It's the -phase angle at those impedances, which are -45 degrees at 50hz and -35 degrees in the mids/highs. (last graph on your link)
This will make the 2ohm load and 3ohm load look more like 1ohm and 2ohm to the amplifier, quite savage.

When you combine low impedance and high - phase angle as this, it's called EPDR (equivalent peak dissipation resistance) and the amp sees this as a much low resistive load.

Read about EPDR here, 5th page down under Lab Report. On the Wilson Alexia's It's PDF so you have to open it. I'll post more links on this EPDR if anyone's interested.

http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0CCIQFjAB&url=http%3A%2F%2Fwww.absolutesounds.com%2Fpdf%2Fmain%2Fpress%2FWA%2520Alexia%2520HFN%25200313-4web.pdf&ei=LFLAVO-6L8LVmgWqyICoBA&usg=AFQjCNEZq3-yhO0zaUOpAjBxXfWo_vYFLQ

Cheers George

If I'm not mistaken, power demands increase exponentially with lower frequency, so a .5 ohm impedance at high frequencies is much less problematic than when typically found in the bass region.

I just know what I've seen and heard over the years with ML speakers in general. They sound top notch with top notch SS amps. Relatively few ML owners use tube amps I would think. Tube amps have never been in the picture.

Yes Ralph is a very smart guy, but he is also a tube amp vendor and well qualified to defend his turf.
George ... right you are. The capacitive phase angle north of 2K Hz is less of a concern than the negative phase angle below 75 Hz, especially coupled with the low impedance.

Yup ... I have a non-techie familiarity with EPDR. Didn't click on your link, but here's a great article on the subject:

http://www.stereophile.com/reference/707heavy

The bottom line is I'll never know for sure how my amp mates with the S-5s until I arrange a realistic audition.

One other positive factor in my favor is that my amp has pretty robust power supply ... 1040 joules. Presumably, ... hopefully, ... that kind of PS muscle can smooth over demands for current in the bass region. But as just stated, I won't know for sure until I plug the S-5s into my rig.
Bruce (Bifwynne), +1 to your post just above, and to George's reference to EPDR and his characterization of the S-5 as a challenging load.

Regarding the on-going disagreements about the suitability of tube amps for driving Martin-Logans and other electrostatics, perhaps we should just declare an impasse at this point. Also, I would refer those interested to this thread, in which all of the present protagonists, and many other knowledgeable folks as well, argued the same issues over the course of a three-page thread.

OK, so much for non-partisanship :-) In that three-page thread I would nominate as the tie-breaking perspective the posts by member Frogman, who as a long-time professional classical and jazz musician, as well as a highly experienced audiophile, unquestionably has one of the most impressive combinations extant of audiophile and musical backgrounds.

Best regards,
-- Al

Yes Bruce and Al, I'm trying to find a Phase Angle graph on the OP's Ethos to see if they are even worse for an amp to look at than just the impedance graph shows they are.

Cheers George