Electrostatics and tubes

Thanks for the clarification @clio09. I believe you have corrected me on that matter before .

I attended the talk Roger gave at Brooks Berdan Ltd., in which he introduced the RM-10. At that time I had a two pair of QUADS, mounted in a frame of my own design. At that talk I asked Roger if he recommended a single RM-9 or a pair of RM-10’s (one on each speaker pair) to drive the four ESL’s, and he told me a single RM-9. He said he did so because of the RM-9’s greater headroom capabilities.

At his next visit to Brooks’ shop, he came over to me and said he had been thinking about my question, and had changed his mind: he now recommended one RM-10 for each ESL pair. By that time I had returned to a single pair of QUADS, so the matter was moot.

I also owned a pair of the QUAD II tube amps made for the ESL’s, and it was easily outclassed by the RM-10. Bill (@whart), you really should get yourself a Music Reference RM-10 Mk.2 for your QUADs!

To add to Ralph’s (atmasphere) expert commentary, probably the most transparent music reproduction I have ever heard was a pair of QUAD ESL’s driven by a pair of his M-60 OTL amps.

Roger Modjeski was also a huge fan of the QUADs, and used that loudspeaker as one of the loads in the development of his Music Reference RM-10 power amp. Roger then took the ESL/tube pairing to it’s ultimate realization: he developed an amplifier in which the tubes directly drive the ESL stators, bypassing the input transformers of the QUAD. He made only a very few pairs of that amp before Cancer ended his life in 2019. I can only imagine how transparent that Music Reference/Direct-Drive ESL pairing must sound.

I heard the Sanders Model 10 ESL’s at two Stereophile shows, and considered the sound they produced to be the best at the shows. At one of the shows I also heard a gigantic pair of SoundLabs ESL’s, but there was definitely something wrong. Amplifier clipping?

Right you are @gumbedamit. He says the same in his reviews of both the LFT-8b and 8c. It can be argued that the opinion of ESL’s by one who doesn’t like ESL’s is of no value. Just as an opinion about a, say, horn loudspeaker by one who doesn’t like horns (I admit to being one such person) is meaningless.

Still, I find it of interest that Guttenberg characterizes the sound of the ET LFT-8 (both b and c iterations) to have the best traits of both ESL’s (transparency) and planar-magnetics (very well known in the Magnepan designs), with less of their faults.

I understand Guttenberg’s reservations about the ESL sound, though I don’t agree with his dismissal of the design. All speakers are a combination of strengths and weakness, and every listener must decide what his or her priorities are, and look for a speaker that provides he or she with the most of what they are looking for at a given price. I find the ET LFT-8 to offer a nice balance of attributes at a very modest price, and remain mystified that the speaker is not more well known and owned.

It took Guttenberg 30 years to get around to reviewing the LFT8! Robert E. Greene also reviewed the LFT-8b in TAS, and there are several reviews in UK mags, all very enthusiastic. I encourage @hotrod6871 to consider the 8b ($3200) or 8c ($4500) before making a purchase.

Steve Guttenberg followed up his review of the Eminent Technology LFT-8b with a review of the new LFT-8c. In the review he gives his opinion that the 8c is a significant upgrade from the 8b, and that he considers it superior to all Magnepan models, and all ESL's (of which he is not a fan). Here it is:

https://youtu.be/R4vC3V00-3Y?si=stiLs8kZ25TJhRsd

@terry9 and @sierratrails: I’m amongst friends!

In the spring of 1973 I paid my first visit to one of the new high end shops that were popping up around the U.S.A. in the wake of The Absolute Sound joining J. Gordon Holt’s Stereophile (Gordon was the mag’s founder and chief---often sole---reviewer) to serve the hi-fi appetites of we boomer generation new audiophiles. The shop (named Audio Arts) was located in Livermore, CA---about halfway between my town of San Jose and the state’s capital, Sacramento (where my mom was born and raised), and was owned and operated by a fantastic guy named Walter Davies, later known for his Last Factory record and tape care products..

Also paying his first visit to the shop that day was Bill Johnson of Audio Research. Talk about good luck! Bill was a pilot with his own little plane, and he flew himself and a complete ARC/Magneplanar system from Minnesota to Livermore, to install in the shop’s excellent listening room (one of the best I’ve ever been in). Back in 1971 I had seen an ARC Dual 50 in San Jose’s best hi-fi shop, but at that time the name meant nothing to me.

The Dual 50 was driving a pair of ESS Transtatic I loudspeakers, for which I was lusting (they unfortunately cost $1200/pr, which at that time this starving musician couldn’t sell enough blood to buy ). The Transtatics featured three RTR ESL tweeters, the first ESL’s I had heard. They reproduced the sound of cymbals as I had never before heard. I now own a pair of them, bought used in 1982 for $400.

Anyway, I spend a few hours listening to Walter and Bill talking all things hi-fi as Bill installed the system, getting myself a nice education. The system was a pair of Magneplanar Tympani T-I loudspeakers bi-amped with D51 and D75 amplifiers, an ARC SP-3 pre-amp, and a Thorens TD-125 Mk.2 with a Decca Blue pickup mounted on a prototype ARC tone arm not yet in production. That was the most consequential day of my hi-fi life! Having heard that system, I just HAD to get it for myself.

Later that year Walter installed the exact same system in my listening room, minus the ARC arm. I paid for the arm upfront, but used a Decca International Arm (on loan from Walter) as work on the ARC prototype proceeded. When the arm was cancelled (it never went into production), I got myself an SME 3009 Mk.2 improved. In using the Decca arm I learned that I don’t care for unipivots.

I was happy with the system for about a year, but when I heard the new Fulton Industries Model J loudspeaker---which used the same RTR ESL tweeters as the ESS Transtatic (as did the original Wilson WAMM, along with a pair of KEF B139 woofers, also the woofer in the Transtatic), though six of them, and a dynamic woofer in a transmissionline enclosure---well, the failings of the Tympani’s became glaringly obvious. Out came the Tympani’s, in went the Model J’s (the sale of the T-I’s and D51 paid for them).

But the honeymoon was short lived; I quickly learned that while the J’s were indeed more transparent than the Tympani’s, and had greater low end weight and extension, the vocals and instruments sounded like they were being squeezed out of three boxes (look up a pic of the Fulton’s to get the picture). Images produced by the Maggies were spread out before me, floating in space, free of the Mylar diaphragms producing them. With the Fultons, those same images were coming through little holes in the wall at the location of the speakers. I learned I was a planar man.

I now own the Transtatics, a pair of Old Quads, a pair of Tympani T-IVa (bought from Kent of Electrostatic Solutions), and two pair of Eminent Technology’s: both the LFT-4 and LFT-8b. Plus Rythmik Audio and GR Research subs. What I need now is a room big enough for them all .

For those who don’t care for this long-winded tale, my apologies. My last of them, I promise (and this time I mean it).

@hotrod6871: The first thing to do is understand that---as @fuzztone told you---Maggies are not electrostatic speakers (and visa versa of course), and the two differ in important ways. What they both are, however, is dipole planar speakers. Dipole as in sound emanating from both the front and rear of the panels, planar as in sound being produced by not dynamic/cone or horn drivers, but by large (with the exception of ESL tweeters like the 3" x 5" ones made by RTR), thin, flat sheets of Mylar. The difference between Maggies (and other planar-magnetic loudspeakers. Magnepan is not alone in making them. See below) and ESL’s is in how the Mylar is set in motion. A google search will explain it all.

If it is Maggies you are considering, you should know that they present a 3-4 ohm load to the power amp, and are very insensitive: 83dB or thereabouts. The load is almost purely resistive, unlike ESL’s, which are in some cases very reactive. The original QUAD ESL is one such case; it presents as low as about 2 ohms up to 50 ohms to the amp, so is highly-amplifier sensitive. The QUAD is not for those new to dipoles, one reason being they are very limited in maximum SPL capability. The speaker is really, really great for "small" music.

But to answer your question, yes, the power needs of Maggies is emormous (I’ve owned three pair in my life, one currently). Depending on the size and sound characteristics of your listening room, and your SPL listening preferences, 125 watts may be marginal (though there are many happy owners of the Maggie/ARC amp combo). Relieving the panels of reproducing low frequencies by adding a sub or two, along with a x/o filter to split the signal at somewhere between 50Hz-100Hz, will greatly reduce the power requirements of the panels.

It might be a wise idea to give a modestly-priced planar-magnetic speaker a try first. Magnepan designed and offers the LRS for exactly that purpose. Spending $6000 on a pair of MG2.7i is to gamble a fair chunk-o-change on liking them enough to keep them. Have you heard any Maggies? How about ESL’s? I would characterize ESL’s as being a little more transparent than Maggies, though the Magnepan ribbon tweeter used in the MG2.7i narrows the gap. A major complain about Maggies is their slight lack of dynamic expression. They also become somewhat opaque at low listening levels.

If you care to consider another planar-magnetic that isn’t as power hungry as Maggies, there is the Eminent Technology LFT-8b, priced at $3200 (including shipping). The LFT-8 has dual binding posts, one for the panels (180Hz up), the other for the 8" dynamic woofer (180Hz down). That makes bi-amping easy: a solid state amp for the woofers, your M-125’s for the panels. The LFT-8 is rated as an 8 ohm load (with about the same sensitivity as Maggies), but the panel itself is an 11 ohm load, which your amps will love.

Here’s a fairly recent review of the ET LFT-8b by Steve Guttenberg:

https://youtu.be/Uc5O5T1UHkE?si=frZqh9SRwmwjJ0MM