Tube Amps, Magnapans and Impedance

@gdnrbob

Many thanks.  I'll ping him.  I have no experience with them but they are intriguing.

@richopp525

For acoustic music, Maggies are incredible.  I always tell the story of how I went to a high-end shop in Palo Alto, CA., with a colleague.  This was 1978 and I was a school teacher.  I heard a sax playing in the back of the store and wandered back for a listen.  I saw instruments hanging on the wall but no sax player.  Turned out it was Magnaplanars powered by Audio Research (with solid silver cabling) from a vinyl recording of Sonny Rollins.  I was completely stunned. I stood there and the owner came in and explained the full set up.  He was gracious enough to play serveral jazz cuts and I was in nirvana.   In no way could I even afford the cartridge!

I made it my mission to own a pair.  I finally did so in 1996 or thereabouts.  I couldn't swing the Audio Research but the custom built Cary pre and amps have served them well over the years. Peter Dahl transformers and Class A all day long.  :-)  Oh, and they will boogie too!  Granted, there is nothing like a cone for moving air for rock and roll and all the derivatives, but they can hold their own.  I am more into timbre, tone and that enveloping natural sound they provide.  Sublime...  They are not for everyone though for sure.

For those who like the Maggie/tube amp combination but can’t or don’t want to spring for a high-powered amp, there is an alternative. Is everyone aware of the fact that Maggies are not the only planar-magnetic loudspeakers on the market?

Bruce Thigpen of Eminent Technology---already well-known for his linear-tracking air-bearing tonearm---found much to like in the Magnepan design, but saw a way to improve upon it: create a p-m driver that operated in push-pull fashion. All the early Magneplanar drivers were single-ended---magnets on only one side of the mylar diaphragm (if you don’t understand why that is a design flaw and weakness, a little research will reward you with the answer). Thigpen created a push-pull m-p driver over forty years ago, patented it, and uses it today unchanged in his LFT-8b loudspeaker. While he was at it, he made the driver an 11 ohm load, much more appropriate for tube amps than are the 4 ohm (and down) Maggies.

Used with a single stereo power amp, the LFT-8b’s p-m midrange driver and ribbon tweeter are combined with the 8" sealed-enclosure dynamic woofer (for 180Hz down), resulting in an 8 ohm load. But the LFT-8b is fitted with two sets of binding posts: one for the woofer, one for the planar panels, so bi-amping the LFT-8b is a breeze and allows one to use a ss amp on the woofer, a tube on the panels.

Magnepan eventually moved to push-pull operation in some of the drivers in their higher-priced models, but retained the 4 ohm impedance. There are some LFT-8b owners who bought them as replacements for their MG3.7’s, overall preferring the ET. $2499/pr shipped or from an ET dealer.

I myself am a long-time Maggie lover, having bought my first pair---the Tympani T-I---in 1972, and am a current owner of a pair of Tympani T-IVa, the ultimate realization of the 3-panel Tympani design (assuming you ignore the MG30 ;-). I very much like the ET LFT-8b, and find it to work quite well with a modestly-powered (100w/ch)---though unusually-well designed and built---tube amp in a moderately-sized room (14.25' x 22')

Frogman knows of what he speaks. The Maggie's need for ridiculous power is a way overblown item that keeps being repeated. The high end dealer here demos 3.7s with a Rogue Cronus Magnum. I run 1.6s with the same amp. Even after having used an amp that pumps over 300 watts, there is nothing missing with the "low" powered amp.

PS...looks like the "not a robot" deal just got even more annoying.

My monoblocks are 80 watts. They do have Peter Dahl transformers which make a huge difference. They deliver the goods and the Maggies seem to like them as far as I can tell. One thing of note is I tend not to listen at super high levels. They are so articulate, musical and transparent, I don’t find the need for high power to get into the essence of the music. That, in fact, was their allure when I first heard them way back when.