Lamm Industries LL2 Deluxe preamplifier
While I reveled in the otherworldly realism of my hi-fi, a different sound caught my attention: the liquid twitter of a barn swallow, whose nest was under the eave outside my window. He made his call four or five times before taking off again, and from several feet away, even heard through a screen window—the kind of material most audiophiles would reject as a loudspeaker grille, for being too "opaque"—he sounded considerably more real, more there, than the music that was coming from my speakers, which now sounded like wallpaper paste by comparison. My enjoyment of Dvorák and Piatigorsky wasn't spoiled, but the little bird refreshed my perspective and reminded me that, although this hobby is all about lying to myself, I should hope never to get too good at it.
Don't be surprised, then, if this equipment report seems a little more sober than most.
The first millivolt is the most important
Lamm Industries, of Brooklyn, New York, makes two different line-level preamplifiers. Their flagship is the L2 Reference, a $14,390, two-box affair that uses vacuum tubes for rectification and regulation, and transistors for gain, and which I've heard only in unfamiliar systems: trade shows and the like.
For its part, the LL2 is Lamm's budget preamplifier—but the greater truth lies not in the word budget but in the word Lamm's: The company's president and chief designer, Vladimir Lamm, is among the most resolute people I've met in domestic audio, and I dare say his concept of an affordable preamp has room for fewer concessions than most. Cheaper parts? No. Reduced stability? No. Any diversion from the topologies he believes are the best? No. Lose the phase switch and the balanced outputs? Maybe...
The same point of view applies to the convenience features found in most other such products. "I lose a lot of business," Lamm says, "because people ask me for a preamp with remote control, and I say, 'No. No. No!' My company exists to make the best sound humanly possible, and anything other than that..."
He didn't finish his sentence. He didn't have to.
There's no hint of otherworldly greatness in the Lamm preamplifier's outward appearance: With its rack-style front handles and standard dimensions all around, the LL2 looks the same as hundreds of other preamps from places such as Fairfax, Virginia and Minnetonka, Minnesota. Only the LL2's decidedly purist approach to volume adjustment—separate controls for the left and right channels, allowing the user to adjust side-to-side balance without an extra potentiometer in the signal path—distinguishes its faceplate from the herd.
But once you notice that little detail, you begin to wonder where they've put the source selector knob. Well, there isn't one. The music signal from the LL2's three pairs of input jacks goes to a very-high-quality two-position switch that directs one pair of signals—from the jacks labeled Direct—straight to the volume pots, then on to the first gain stage. The other side of that switch feeds a second, identical switch, which gives the choice between the remaining two stereo inputs, called Line 1 and Line 2, and then carries on to yet another switch, for the tape loop. Consequently, although all three input pairs address the same active circuitry, the Direct pair has the theoretical advantage of two fewer switches in the path, and so is intended for use with the listener's primary music source.
The first active device seen by the signal in each channel is a 12AU7 tube, which the designer selected for its comparatively low µ (amplification factor). In the LL2's circuit, that double triode is used as a single triode, with its two halves in parallel. The two halves of the second double triode, a 6DJ8 tube, are wired in shunt-regulated push-pull (SRPP) mode, a topology known for its distortion-canceling properties, relatively high gain, and—best of all in a preamp that might be called on to drive long interconnect cables—its commendably low output impedance.