audio research

Hybrid tube/FET stereo preamplifier.





MSRP (US new retail)


Frequency response High level section: ±.5dB, 5Hz to 50kHz, -3db points below 1Hz and above 200 kHz
  Magnetic Phono: ±.3dB of RIAA, 30Hz to 40kHz
Distortion (THD) Less than .01% at 2V RMS output
Noise & hum High level: (1) 70 µV RMS maximum residual unweighted wideband noise at main output with gain control minimum (98 dB below 5V RMS output) (2) More than 100dB below 1V RMS input (less than 7 µV equivalent input noise)
  Phono: 0.12 µV equivalent input noise, IHF weighted, shorted input (78dB below 1mV input)
Gain Phono input to tape output: 46 dB
  High level inputs to tape output: 0 dB
  Phono input to main output: 66 dB
  High level inputs to main output: 20 dB
Input impedance Line inputs: 50 K ohms
  Phono: 47K ohms (provisions for any value below 47K ohms or added input capacitance for matching certain magnetic cartridges.)
Output impedance 250 ohms main output, 1000 ohms recorder output. Recommended load 60K - 100K ohms and 100pF. (20K ohms minimum and 1000pF maximum)
Output polarity  
Maximum inputs Magnetic phono, 200mV at 1kHz (1000mV RMS, 10 kHz). High level inputs essentially overload-proof.
Rated outputs 2V RMS 5 Hz to 50 kHz, all outputs; 60K ohm load (main output capability is 50V RMS output at .5% THD at 1kHz into a 100K ohm load with 5V RMS high level input)
Power supplies Electronically-regulated low and high voltage supplies and electronic decoupling. Shielded toroid transformer. Line regulation better than .01%.
Tube complement (1) 6DJ8/ECC88 dual triodes (Hybrid FET/Tube audio circuit, solid-state power supply)
Power requirements 100-135VAC 60Hz (200-270VAC 50/60Hz) 60 Watts
Dimensions 19” (48 cm) W x 5 ¼” (13.4 cm) H (standard rack panel) x 10 ¼” (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 12 lbs. (5.5kg) Net, 21 lbs. (9.6 kg) Shipping


Issue 61 (Special Report), Issue 62 (Consideration)
Vol. 13 No. 6