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 1 response by jayh31

I recently auditioned the LM 518 mated to a pair of Harbeth 7s, the same speaker Tim used in his excellent review. It sounded absolutely horrible. Congested, bloated, dull, slow, and completely devoid of any dynamics. Everything from the lower mids down was a complete mess. The dealer was apologetic and as he said, "embarrassed" that I set a Saturday aside to drive the considerable distance to hear (and not hear) this highly regarded amp that we both agreed was unlistenable. I was really wanting to love this amp and was sorely disappointed when it wasn't even close. The dealer attributed the poor sound to what did seem to be a rather pronounced echo in his listening room, however, it sounded so poorly, I wasn't convinced that could be the primary reason and declined his generous in-home audition offer. As a consequence I've since ordered the Coincident 845 SE and can't say that based on my experience, I could recommend the 518 to anyone.