Audio Research SP 6 C-1

Specifications
Frequency response High level section: ±.25dB, 10Hz to 30kHz.
-3dB points approximately .1Hz and 250kHz into hi-Z load.
(-3dB point approximately 1 Hz into 100kOhm load.)
Magnetic phono: ±1dB of RIAA from 30Hz to 15kHz.

High level:
(1) 250 µv RMS maximum residual unweighted wide-band noise at main output with gain control minimum (86dB below 5V RMS output).

(2) More than 90dB below 1V RMS input (less than 20 µV equivalent input noise).

Magnetic phono: 5 µV equivalent input noise, wideband RMS (-66dB reference 10mV input).

Gain Magnetic phono input to tape output, 34dB. Magnetic phono input to main output, 60dB. High level inputs to tape output, 0dB. High level inputs to main output, 26dB.

Input impedance 50 kOhms, all inputs. (Magnetic phono may have any value from 10 ohms to 100 kOhms substituted. Also has provision to add input capacitance for matching certain magnetic cartridges.)

Output impedance 500 ohms at 1kHz, rising to 2.1 kOhms at 20Hz, all outputs.
Recommended minimum load for maximum audio quality, 20 kOhms.

Tube complement
SP-6C: (2) 12AX7 LN, (2) 12AX7, (2) 6922

Power requirements 105-120/210-240 VAC, 50/60 Hz, 35 watts.

Other
Dimensions 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 5/8" (4.1 cm) forward of front panel.
Rear chassis fittings extend 7/8" (2.3 cm).
Weight 22 lbs. (10 kg) Net, 30 lbs. (13.75 kg) Shipping