Eminent Technology LFT-8c Robert Greene review

I just wanted to share my change of power amplifier in driving the LFT-8c.

Previously, I had a pair of Von Gaylord Nirvana mono blocks, 100W push-pull triodes with eight Tungsten Sol 6550 output tubes and two pairs of 6SN7 signal tubes. I replaced them with a pair of Line Magnetic LM 523 PA. These are a pair of mono blocks rated at 50W. Each amp comes with factory installed Psvane OEM 805 output tube driven a 300b, a 274b rectifier, and a 6SN7 + ECC82 ( JJ ) signal tubes. Each weigh about 35 kg. This particular Line Magnetic power amps may be unfamiliar to most in North America as the brand is known for its integrated amps. Since I have a good tube preamp, I opted for its power amps. 

I have around 25 hours on them so hardly broken in. But the sound quality that is produced by these amps through the 8c is of many orders of magnitude higher than  the previous amps.  these 50W SETs’ pair magnificently with the planars. The overall gain from the preamp is actually higher. With CD’s the speakers play louder at the same setting while with vinyl it is cartridge dependent, but not any lower than before. The main improvement so far : 1. The image specificity of the soundstage is greatly enhanced. Now players are fleshed out and distinct, individually sculpted, and floating in space with more relief. 2. The background is several notches quieter than before. I finally get to experience what a blacker background feels / sounds like. 3. And as a consequence, the  dynamics contrasts between quiet and loud passages are more pronounced leading to a much more engaging and enjoyable connection to the music. 4. The critical midrange magic and even order harmonics that single ended triodes are renowned for are present in spades. Again this translate into a more emotional connection with the music. 5. The bass response is more nuanced and refined. Definitely it blends more within the the soundstage. The bass volume was turned up maybe 2-3 db. And there is more the upper bass energy in the mix. 

The VG Nirvana was very competent, never an issue with headroom, soundstage width, or transparency. But I felt that there should be more magic to the midrange and upper bass. While SET are primarily used with high efficiency speakers, horns..etc, I had an intuition that maybe there is a right set of SET that would work with Planars. Given that the bass frequencies are passed off to a powered module in the 8c, the overall efficiency increases to 86db from 83db of the 8b. This is still very low in SET terms, but I thought maybe a higher powered SET could work. My conclusion is that with the ET LFT-8c it is definitely worth experimenting with better amplification. The speakers are most definitely not the weak link in my system. With the new amps they have transformed into a different and much better set of speakers. 

@slaw:

Hey Steve, I was pleased to see you are considering the ET LFT-8c as "a final speaker."

I have done exactly that, though I have kept my other speakers as well (QUAD ESL, Magneplanar Tympani T-IVa, ET LFT-IV, ESS Transtatic). Though no speaker is optimum for all types of music (for example the QUAD is not appropriate for Metal), considering your musical taste I consider the ET LFT-8 (any iteration) to be a good candidate.

The single LFT driver is employed to reproduce all frequencies from 180Hz up to 10kHz, with no crossover in that frequency range! The result is that the root note of most strings on an acoustic guitar and all their harmonic overtones are reproduced with the same timbre (correctly pronounced tam-bur, not tim-ber), tonality, color, and physical "density". The same is true of other acoustic instruments such as piano, fiddle, drums & cymbals, upright bass (excluding it’s bottom two octaves), and voices. Great for Singer/Songwriter, Bluegrass, Folk, Country, small scale Classical music, etc. Add a pair of GR Research/Rythmik Audio OB/Dipole Subs and bigger and/or more "aggressive" music may also be listened to at fairly loud SPL

As for your listening room, the common recommended distance for dipoles from the wall behind them is 3’, with 5’ an even better distance. One way to achieve that 3 (or 5) foot distance is to toe-in the LFT-8 so that it’s rear wave is reflected off the side wall rather than the front wall. That increases the distance the rear wave of the speaker travels before it reaches your listening position (the side wall reflection traveling to the front wall, where it is again reflected), thereby increasing the delay in time between the front wave of the speaker and it’s rear wave. You want to get a 5’ total distance, which creates a 10ms delay. That "tricks" the brain into perceiving the front and rear waves as separate sources. Anything less than 10ms is heard as a smearing of the front wave.

Thanks for the post Eric. Pretty sure my room is too small, would still like to hear them.

Going to listen them to the 3rd time at BAT in Temple NH.  First time with vinyl (SOTA w/ SME 309 and Hana) and Classe DR-9 and Schiit Kara.  2nd time with Schiit Tyr and Yggy Singular.  

As a mostly panel guy from '78-'05 and sporadically since I've owned and heard many of them.  The 8c's beat on the Maggies (1, 1.7i, 2, 3.3, 3.7i) in low bass, and mid clarity.  The true ribbon Maggies, Duetta Sigs and Ralls are my favorite tweets and I assumed the ET was - its so bloody good.

The woofer/mid transition is well better than the ML hybrids (SL-3, Vista, Vantage, 9, 11) being at a lower frequecy.

The ET are not head bangers but handle volume better than most of them.  The depth of image I heard on the Tyrs was staggering.  Timbre, stage, placement in stage and lack of IM were also notable.  Given the rising prices these days its astounding they are $5600.  

Found all these posts on placement to be very interesting and seem to agree as far as I delved with what I have heard experimenting with them so far.

@wlamt22  Please post your thoughts on your next audition. I assume you’re planning on picking up a pair. 

I can’t disagree on your thoughts about Maggies.  I went to the Florida and Axpona shows this year and specifically spent time, 2 visits to the Maggy rooms at each show, with the Maggy 1.7i, 1.7x, 2.7i speakers.  I ended up visiting each room twice as I had a hard time believing they sounded..so..meh.  I though maybe it was the recordings, but, they sound how they sound. Very thin and lifeless. Minimal bass.  Really no comparison to the LFT 8b’s I was listening to at the time. I recently upgraded to the 8c and Maggies wouldn’t hold a candle to them. 

With respect to the Ai thing I posted on placement..I should have pared those posts down a bit, but it was pretty exciting at the time...and is still very useful. The key in all those posts boils down to the calibration curve at the end.  Using the curve/plot, anyone can quickly get well down the road toward an optimal setup of their LFTs.  I’m still using about 24 degrees of toe-in for my setup..it’s terrific,  I ran across a large list of great Chesky recording titles yesterday and found them on Qobuz..WOW.   Soo good..