On the Bench
The following measurements are with one
channel driven into 200 kOhms, using the XLR balanced output.
At 1 kHz and 2 volts output, THD+N was 0.01%,
which is well within spec. Signal-to-Noise was 86 dB, better than spec.
IMD, using 60 Hz and 2 kHz sine waves, was
0.005% at 2 volts output.
At 5 volts output, IMD was even less, at
THD+N vs. Frequency for 2 volts and 5 volts
output was 0.01% and 0.005% pretty much flat across the audible band, which
translates to a very neutral sound. This
is top notch performance.
THD+N vs. Output indicates that the L2 can
deliver a huge amount of voltage. This is with just one channel being
driven, but nevertheless, two channels will still be able to deliver lots of
juice. Notice that with the RCA unbalanced output, the lowest distortion is
at 2 volts, while with the XLR balanced output, the lowest distortion is at
15 volts. From 10 mV to 2 volts, the RCA output has about 25% less
distortion than with the XLR output.
This kind of power will ensure that every bit of detail in the music
reaches your power amplifiers. That includes any large transient peak, which translates to a fantastic dynamic range.
The measured frequency response was 10 Hz to
200 kHz ± 1 dB.
I can see why Lamm Industries has not changed
the design of the L2 Reference Preamplifier over the years of its life. There is no reason to alter
any part of the product. It is superb. What other adjective is there to
- John E. Johnson, Jr. -