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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.
broadstone
tomcy6's avatar
tomcy6
2,638 posts
 
OK. I don't want to complicate the discussion between George and Ralph about power ,voltage and current.

I'm just wondering why an amp that doesn't double down at 4 ohms and again at 2 ohms can't deliver the small amounts of energy needed for a speaker to produce the low sound pressure levels (loudness) of the overtones that occur at 20khz. It seems that speakers would require very low amounts of whatever form of electricity is appropriate, be it called power, volts or current, to reproduce the overtones at 20khz. Does the .5 ohm impedance at 20khz make it just about impossible for an amp to provide energy to a speaker?

Maybe this isn't the time to add this to the discussion, if that's the case, I'll butt out.
georgehifi's avatar
georgehifi
10,312 posts
 
Look at Stereophile tests (12 & 13 posts back)on tube amps into their simulated speaker load, and what happens to the frequency response, and then magnify that many times for the OP's Ethos speaker, as they are more severe than the simulated load.

Here is a Parasound amp that can do current, note how with the same simulated load frequency response this amp hardly differs from just an 8ohm resistive load. Compare it now to the tube one and then multiply the difference by quite a few times, because of the OP's speakers more severe load characteristics.
[url]http://www.stereophile.com/content/parasound-halo-jc-1-monoblock-power-amplifier-measurements[/url]

Cheers George
clio09
3,374 posts
 
The Music Reference RM-200 has 1, 2, 4, and 8 ohm tap configurations. Although it is a hybrid amp, in this case the input is solid state, while the output is tube driven.
georgehifi's avatar
georgehifi
10,312 posts
 
Looks like Clio09 may have the right tube amp for the OP's Ethos speakers, should work well either off the 1ohm or 2ohm tap and maybe not sound like a fixed tone control, and only one transformer in the way.

And you can see it in the second graph working off the 1ohm tap, only slightly deviates of dead flat when driving the simulated speaker load, maybe it will be a bit worse with the .8ohm of the OP's Ethos.
[url]http://www.stereophile.com/content/music-reference-rm-200-mkii-power-amplifier-measurements[/url]

Whether or not it will have enough watts off the 1 or 2 ohm tap is another story, this will depend on how loud the OP likes to listen, because the lower the tap impedance the less wattage is available, but higher current and lower output impedance (higher damping factor).

Cheers George
atmasphere's avatar
atmasphere
12,164 posts
 
The ZERO is not a band-aid. It is a problem solver, and very effective- usually removing coloration rather than adding it. There are many accolades on the zeroimpedance.com website and the product has been around now for nearly 20 years.

The issue we are dealing with here is that Martin-Logan recognized that solid state amps dominate the market, and they wanted to be part of that- because it sells more speakers. So they made their impedances extremely low.

The problem is that ESLs have the same efficiency at all frequencies. If you combine that with an amplifier that can double power as George suggests, the result is brightness. If the amp can otherwise drive the load but not double power, the tonality will be correct.

The ZERO allows this with many tube amps which otherwise would not be able to drive the half-ohm load which is what a Martin-Logan is at 20KHz. Sure, there is not much energy up there, but if you have too much it gets painful.
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