audio research
LS2

Description
Hybrid tube/FET stereo line stage. Exists in two versions: LS2 and LS2B (Balanced).

Introduced
1991 (LS2)
1992 (LS2B)

Discontinued
?

Revisions
LS2 MKII (1994)
LS2B MKII (1994)

Options
Remote control

MSRP (US new retail)
$2,495 (LS2)
$2,995 (LS2B)
$2,650 (LS2 MKII)
$2,995 (LS2B MKII)

Specifications

LS2B MKII:

Frequency response ± .5dB, 1Hz to 100Hz, -3dB points below 0.1Hz and above 300kHz
Distortion (THD) Less than .01% at 2V RMS output.(Typically less than .005% in midband)
Noise & hum 20µV RMS residual 1HF weighted noise at main unbalanced output with gain at minimum (100dB below 2V RMS output). Balanced input noise 100dB below 1V input.
Gain Main Output: 18dB (Optional 9dB gain reduction through an internal jumper)
Balanced output: 24dB (Optional 9dB gain reduction through an internal jumper)
  Tape output: 0dB
Input impedance 50K ohms unbalanced, 3 megohm balanced.
Output impedance 200 ohms main output. 400 ohms Balanced 1, Balanced 2 (10K ohms minimum load and 2000pF maximum capacitance)
Output polarity  
Maximum inputs 20V maximum unbalanced, 8.5V (+21dB) maximum balanced
Rated outputs 2V RMS 1Hz to 100kHz into 60K ohm load (maximum output capability is 30V RMS [60V RMS balanced] output at 05% THD at 1kHz into a 10K ohm load)
Power supplies Electronically-regulated low and high voltage supplies. Two transformers (toroid for high voltage). Line regulation better than .01%
Tube complement (1) 6922
Power requirements 100-135VAC 60Hz (200-270VAC 50/60Hz) 60 watts maximum
Other  
Dimensions 19" (48 cm) W x 5 1/4" (13.4cm) H (standard rack panel) x 10 1/4" (26cm) D. Handles extend 1 5/8" (4.1cm) forward of front panel. Rear chassis fittings extend 7/8" (2.3cm).
Weight LS2: 13 lbs. (5.9 kg) Net; 21lbs.(9.5 kg) Shipping.
  LS2B: 14 lbs. (6.0 kg) Net; 22lbs.(10 kg) Shipping.

Reviews

Issue 100 (LS2B)
Vol. 14 No. 10 (LS2), Vol. 16 No.1 (LS2B), Vol 16. No 4 (LS2B)

Pictures

LS2:

LS2 MKII:

LS2B:

LS2B MKII: