Power tubes as drivers -- Line Magnetic

TB. Looks like you already found the Steve Huff review of the 518 and 219. He's having such success driving your speakers with the LM amps. I haven't heard the 219, but have had similar experience with the 518's "fat" sound. With my Merlins, this is very welcome and I'm happy to have a bit more bass. Mind you, that isn't code for "bloated"-- it's taut and tuneful bass rather than one-note boom. Steve does seem to prefer the 219 with the Sonus Fabers, but I believe that amp is about $3k more than the 518 and those 300b tubes make for expensive tube rolling, especially considering how expensive 845s are.

Steve's experience should give you a lot of comfort. My dealer wouldn't let me bring the amp home either, and bringing my speakers into the shop was definitely a distant second choice, but I did get to spend as much time as I wanted driving my speakers with the 518 and was therefore absolutely sure it was the right choice. It's a bit more hassle, but you get to the same desired place. I also got the benefit of the store's expertise: without their suggestion and blessing I would never have thought/dared to change output taps on the fly to experiment and end up discovering the 16 ohm taps sounded best on 8 ohm nominal and 6.5 ohm minimum speakers.

Dkidknow,
Good post! I had also suggested taking the speakers to the dealer. Tboooe has some reservations about the LM amplifier's ability to drive the Sonus Faber, well this would address that concern. Steve Huff found the 518 to be "very close" to the 219 amp and said both drove his SF speakers effortlessly. For 3000.00 dollars less the 518 seems a terrific buy.
Charles,

testing

I have the 518IA and have experimented with the various power tubes and to my ears the vintage KT66 tubes sound the best. Sweeter and smoother than the 6l6 or EL 34. My second favorite is the 6V6. This amp requires extended break in time before it blossoms.

I own the Line Magnetic 518IA. I have reviewed it on www.wallofsound.ca

First, the stock power tubes are great. They are the Psvane HiFi Series. Good to see that LM didn't just put cheap entry level Shuguangs in. I just bought a pair of HiFi Series from PartsConnexion. They are identical to the stock tubes.

The most important tube to roll is the 12ax7. I have some Psvane Treasure mk2's in right now. These are remarkable tubes--brilliant from top to bottom.
My favorite, though, is the TJ Full Music 12ax7. So warm! The new production Genalex Gold Lions work very well too.

Second, in order of importance, I think, is the rectifier. I would remove the stock Shuguang and replace it with NOS or with a current production Mullard, Genalex or Tung-Sol. I have the current production Mullard. This, plus the Psvane 12ax7s, has eliminated all hum. Plus consider an Emotiva CMX-2 to get rid of hum produced by your line.

Third, the driver tubes. I am a 6L6 freak. I have over a dozen pairs than I use in single ended amps. After rolling all sorts of 6L6s and EL34s, I settled on... wait for it... Shuguang Treasure black bottles. The ones sold about 2 to 3 years ago. They impart a muscular tone and rhythmic drive to the amp that I find compelling.

This amp really is incredible. It is so fast, but so smooth. It has unlimited reserves of power with most dynamic speakers. You won't use it for Maggies, but virtually everything else will work.