Frequency response

± .5dB, 1.0Hz to 100kHz -3dB points below 0.1Hz and above 300kHz

Distortion (THD)

Less than .01% at 2V RMS output. (Typically .005% in midband)

Noise & hum

15µV RMS maximum IHF weighted noise at main output with gain control minimum (more than 102dB below 2V RMS output)


Main output - 13dB unbalanced


Tape output - 0dB

Input impedance

100K ohms.

Output impedance

200 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 1Hz to 100kHz, all outputs, 60K ohm load (maximum output 25V RMS at 1/2% THD into 100K ohms)

Power supplies

Electronically-regulated low and high voltage supplies. Line regulation better than .01%

Tube complement

(4) 6922/E88cc dual triode

Power requirements

100-135VAC 60Hz (200-270VAC 50/60Hz) 25 watts minimum


Inputs (5): tape, tuner, CD, video, aux

Controls: Gain, input selector

Toggle switches: power/off, mute/operate


19" (48 cm) W x 5 1/4" (13.4 cm) H (standard rack panel) x 10 1/4" (26 cm) D. Handles extend 1 1/2" (3.8 cm) forward of front panel. Rear chassis fittings extend 1/2" (1.3 cm).


9.8 lbs. (4.5 kg) Net, 18.8 lbs. (8.5 kg) Shipping.


Preamplificatore di linea Audio research ls7