The LS1 draws heavily upon the proven hybrid circuitry used in Audio Research preamplifiers. A single 6DJ8 dual triode vacuum tube is used to provide most of the 20dB overall gain, while associated FET devices provide initial gain at input, and current gain following the vacuum tube. Power supply design is virtually identical to the SP9 pre-amplifier, giving the LS1 a lifelike sense of ease and dynamic expression.
Specifications
Frequency response: ± .5dB, 5 Hz to 50 kHz. -3dB points below 1Hz and above 200kHz.
Distortion (THD): Less than .01% at 2V RMS output. (Typically less than .005% in midband)
Noise & hum: (1) 70µV RMS maximum residual unweighted wideband noise at main output with gain control minimum (98dB below 5V RMS output) (2) More than 100 dB below 1V RMS input (less than 7µV equivalent input noise.
Gain: Direct input to main output: 21 dB. CD input to main output: 11 dB. High level inputs to tape output: 0dB. High level inputs to main output: 21dB.
Input impedance: 50K ohms (150K ohms CD, 100K ohms Direct).
Output impedance: 250 ohms main output. Recommended load 60K ohms and 100pF. (20K ohms minimum and 1000pF maximum).
Output polarity: -
Maximum inputs: 20V maximum
Rated outputs: 2V RMS 5Hz to 50Hz, all outputs, 60K ohm load (main output capability is 50V RMS output at 1/2% THD at 1kHz into a 100K ohm load with 5V RMS input).
Power supplies: Electronically-regulated low and high voltage supplies. Shielded toroid transformer. Line regulation better than .01%.
Tube complement: (1) 6DJ8/ECC88
Power requirements: 100-135VAC 60Hz (200-270VAC 50/60Hz) 50 Watts maximum.
Other: Hybrid FET/Tube audio circuit, solid-state power supply.
Dimensions: 19” (48 cm) W x 5 1/4” (13.4 cm) H (standard rack panel) x 10 1” (26 cm) D. Handles extend 1 5/8” (4.1 cm) forward of the front panel. Rear chassis fittings extend 7/8” (2.3 cm).
Weight: 12 lbs. (5.5 kg) Net, 21 lbs.(9.5 kg) Shipping.