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.

When I was amp shopping for my 3.7i I was considering McIntosh with autoformers but was told by the manufacturer themself that autoformers did not work well with Maggie's. As long as your amp puts out high amperage you will be fine, it matters more than watts.

I ended up going with a Pass 250.8 which really makes Maggie's sing.

If you enjoy your sound stay with it and enjoy the music 🎶.