audio research

Tube stereo line stage.

From the ARC website

The LS15 is an all-new line-level preamplifier which replaces the LS2/2BMKII series. It features all-tube gain (12 dB standard) using four 6922 twin triode tubes in a Class A, fully differential zero feedback (balanced) circuit with electronically regulated high and low-voltage supplies. The LS15 includes handheld IR remote control of all essential front-panel functions. An onboard microprocessor controls a 70-step electronic relay attenuator and 5-position input selector. An additional Direct input (balanced) provides a highest-signal-purity path for your favorite music source. A total of two balanced and five single-ended (including tape) dedicated inputs are included.

Main outputs are balanced and single-ended, with one pair of single-ended tape outputs. Spring-activated toggle switches activate electronic relays to control key functions with minimal signal degradation. Factory-set gain of 18 dB is optional at no charge. The anodized front panel is available in natural aluminum or black, cabinet style or with rack-mount holes.




Platinum grey faceplate

MSRP (US new retail)


Frequency response ± .5dB, 2Hz to 30kHz at rated output. -3dB points below 0.3Hz and above 80kHz.
Distortion (THD) Less than .01% at 2V RMS balanced output
Noise & hum 25µV RMS residual IHF weighted balanced noise output with gain control at minimum, 98dB below 2V RMS output
Gain Main output: 12.5dB balanced, 6.5dB SE
  Tape output: 0dB
Input impedance 200K ohms balanced, 100K ohms SE
Output impedance 600 ohms balanced, 300 ohms SE Main (2), 40K ohms minimum load and 1000pF maximum capacitance.
Output polarity  
Maximum input 14V RMS maximum balanced, 7V RMS SE
Rated outputs 2V RMS (1V RMS SE) into 200K ohm balanced load (maximum balanced output capability is 30V RMS at less than 1% THD at 1kHz
Power supplies Electronically regulated low and high voltage supplies. Automatic 30 second warmup mute. Automatic brown-out mute.
Tube complement (4) 6922/ECC88 dual triode. (Vacuum tube audio circuit, solid-state power supply)
Power requirements 100-135VAC 60Hz (200-270VAC 50/60Hz) 35 watts maximum
Other Inputs: SE1, SE2, SE3, SE4, Bal, Direct (Bal) and Monitor (SE)
  Outputs: 2 Main Bal, 1 Main SE, 1 Record SE
Dimensions 19" (48 cm) W x 5.25" (13.3 cm) H (standard rack panel) x 10.5" (26.7 cm) D. Handles extend 1.50" (3.8 cm) forward of the front panel.
Weight 11.6 lbs. (5.3 kg) Net; 20 lbs.(9.1 kg) Shipping.


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