The Magnificent Lamm Amp
Posted Mon Apr 7, 2008, 1:42 PM ET — By John
Atkinson
The are small amps, there are large amps, there are stereo amps,
there are mono amps, and then there are Vladimir Lamm's ML3
Signature two-chassis monoblocks, demmed at FSI with Verity
Lohengrin speakers, a Lamm L2 Reference preamplifier, LP2 phono
preamp, NeoDio CD transport and DAC, and Kubala-Sosna cables, and
Critical Mass Systems racks.
The ML3 Signature runs a single Russian GM70 directly heated
output tube (introduced in 1948, the year I was born) with 1200V on
the plate to give 32 watts into 8 ohms. The GM70 is driven by four
paralleled 6N30P "Super Tubes," with a single 12AX7 as the
input stage. The choke-smoothed power supply in a separate chassis
uses four 12AX3 diode tubes as a bridge rectifier to derive the
high-voltage rail for the output tube, with another two 12AX3 tubes
supplying DC to the front-end tubes.
Listening to Louis Armstrong singing "Blues in the
Night" from LP, I auditioned the amps with no negative feedback
and just 1.2dB of negative feedback. You wouldn't have thought it
would make a difference, but darned if switching in even this
minimal amount of feedback—which, in theory, should make the
amplifier perform better—didn't diminish the enormous sense of
space on the recording.
Oh, the price? Each pair of ML3
Signatures costs $139,290 and takes two weeks to manufacture.
http://blog.stereophile.com/fsi2008/040708lamm/