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Power tubes as drivers -- Line Magnetic

I just purchased a LM 518 IA, which is a 22 watt SET integrated using 845 tubes. The amp uses 2 6L6 as drivers and 12ax7 for input.

I'm picking up the amp this week, and although I haven't seen the user manual yet, From what I can gather, virtually any power tetrode or pentode, including EL-34, KT-88, 6L6 and 6V6 can be used as a driver in this amp. Of course that means I'm getting ready to try a buncha tubes.

My current thought is to pick up decent, but not expensive, current production samples of the various tubes (probably all made by the same manufacturer to maintain some control) so I can get a handle on which sound I prefer most, then move on to more expensive and probably NOS versions of those tubes I like best. Just checking in with the community for reality check on if this makes sense to anyone else.

Also, I've seen on various tube sellers sites reference to "this (noisy/micro phonic) tube is only suitable for use in a driver stage . . . ." Can I infer from this that I can get away with slightly dodgy driver tubes and thus buy really fancy schmancy tubes in low grade and still achieve good results?

Will appreciate your thoughts.

D
dkidknow

Showing 4 responses by charles1dad

charles1dad's avatar
charles1dad
10,250 posts
 
Dkidknow,
Congratulations with the new amplifier. I get the impression that the Line
Magnetic 845 amplifiers are exceptionally good and possess excellent drive
capabilities. Based on owner reports like yours and also reviews, these LM
SETs are using high quality output transformers coupled with good power
supply design. As Ralph noted, the driver tube/ stage is robust.
I don't think Ralph would be surprised with your results using the 16 ohm
tap, you have to experiment with different speakers to find the best tap
usage. This amp offers much flexibility to tailor your sound with driver tube
choices. Also different brands of 845 offer additional fine tuning, there's
great potential with your amplifier. I believe that it's a true High End bargain.
Charles,
charles1dad's avatar
charles1dad
10,250 posts
 
Hi Tboooe,
It's unfortunate your dealer is that rigid with you as a very interested customer.
Why not just take your speakers to him. At the very least you'll be able to assess amp drive capability with the speakers.
Charles,
charles1dad's avatar
charles1dad
10,250 posts
 
Tboooe,
I like your attitude, find a more cooperative dealer. One of the supposed advantages of a brick and mortar dealer is providing equipment for home auditioning.Truemaineiac what increased Tboooe's interest is a review of this very amplifier driving his speakers brilliantly.
Charles,
charles1dad's avatar
charles1dad
10,250 posts
 
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,
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