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
Running specific tones probably won't help you too much as already stated. However, I can tell you a couple things I do to A/B speakers and identify a variety of issues.

1. Run pink noise through speaker A and then speaker B. You can probably hear differences even in mono, but go to your listening position and compare in stereo too.

In my experience, whichever you think sounds better with pink noise will usually correspond to better sound when regular music is played.

It's not a scientific or full-proof method, but considering the primitive material some people use as "reference" tracks, it's no worse and makes it much harder for you to be fooled by biases or other things going on with more complex music (i.e trying to judge vocals, bass, soundstage, extension, sibilance, etc. all at the same time).

2. Leverage technology. I use Jriver as playback for digital material and there is an option under DSP playback to see an "Analyzer" on screen while the music plays. It will give you a good idea of the frequencies being reproduced and their "volume" relative to other frequencies.

You might ask.."How does that help me?"...Well, it first helps you from making inappropriate conclusions.

For example, I've had more than a few audiophile friends use a particular test track as their "reference". I was often surprised that they would sell certain high quality speakers that they said were too bass heavy, while cheaper monitors sounded better to them.

Come to find out...if you look at the material via the Analyzer, it SHOULD sound bass heavy at certain points. That's how it was recorded. The amount of sub 100hz material is double what is over 600 hz for most of the song.

A lot of what people pass around as "audiophile" recordings are not really good to use as a reference. They just sound good. A true "reference" requires something you can compare with in real life. Since most people aren't at the live studio recording, your best bet is to listen to acoustic music and/or leverage technology to at least give you data about how the original recording was mixed.

For those with ears that qualify for Mutant X-Man status, these tips are unnecessary. However, I've found them helpful.
Broadstone, If that same CD track is what irritates you on other systems, one strong possibility is the recording itself, unless you used the same CD player in those systems as well.

How about this- are there any recordings that sound fine on your system and are not irritating?
Atmasphere, in each system that I used for this test the players were different; one is my own which is the Shanling CD-100, another is an old Theta, and the third source is our Apple TV playing Apple lossless files. The results are the same in all cases using multiple CDs when the offending frequencies come up. For example, I can't listen to anything Celine Dione sings except at VERY low volume. Mostly, though, because much of my listening is to solo guitar, there are only a few passages that bother me so, yes, most most of what I listen to is pleasing and I generally enjoy my system very much.

Labtec, I got out the old test CD and tried listening to pink noise but didn't quit get the part about a comparison. The test disk presents pink noise starting at the left speaker, then right, then simultaneously, both in and out of phase. The thing I didn't expect nor understand is that the out of phase sound was almost exclusively from the right speaker. I'm sure I'm missing something here.

Broadstone Hi.

Written bench test results from one review on ML Ethos:
"Measured overall impedance was low at 4 Ohms, in fact surprisingly low considering the bass unit is powered. This is due to the electrostatic panel that comes in hard at 400Hz our impedance analysis shows, careering down to 1 Ohm at 20kHz – ouch!"

I'll look for graphs that back this test statement up.

But from what was said to get the very best from the ML Ethos you need an amp that can that can deliver good current down to at least 2ohms, so it stays flat over the frequency range, and not start behaving like a tone control at different load impedances.

That means "close" to doubling the 8ohm spec wattage to 4ohms and again doubling to 2ohms

EG:
8ohms-50watts
4ohms-100watts
2ohms-200watts

Cheers George
George, this is my 6th pair of Martin Logans and I've seen the graphs so your observation is absolutely correct. I'm using a Peachtree Audio 220W power amp but I don't know how adequate its current capabilities are in regard to the impedance increases that you describe. However, I'm 72 and starting to be convinced that a significant part of my problem is related to hearing changes that have occurred over the years.