Предусилители — Audio Research Reference 10

The Reference 10 is a two-chassis valve line stage from Audio Research, developed as the next step after the company's Reference Anniversary model of 2010. It is hand-soldered in Minnesota, with a separate power supply unit feeding the audio chassis, and it was listed at USD 42,000. The signal path is fully balanced, fully discrete, all valve and pure Class A, with no feedback applied.

Key specs that matter

There are seven inputs in total, six for main sources plus one processor input, each available on XLR and RCA. Outputs comprise two main sets and one tape output, again on both connector types. Main gain is 12 dB balanced and 6 dB single-ended, while the tape output runs at 0 dB. Input impedance is 120 kohm balanced and 60 kohm single-ended, while output impedance measures 600 ohm balanced and 300 ohm on the single-ended main output. Response reaches from 0.1 Hz to 200 kHz within plus 0 and minus 3 dB into a 200 kohm balanced load. Distortion stays under 0.006% at 2 V RMS balanced output, and IHF weighted residual noise is 1.7 microvolt RMS, 109 dB below 2 V. Crosstalk is -80 dB or better at 1 kHz. Maximum input is 20 V RMS balanced or 10 V RMS single-ended, and the output can swing up to 30 V at under 0.5% THD at 1 kHz.

Engineering and use context

Eight 6H30P dual triodes carry the audio, and the power supply adds two 6550C and two 6H30P for electronic regulation, with line regulation better than 0.01%. Dual mono layout runs from the supply through the audio circuits, with separate low and high voltage transformers for each channel. Audio Research fitted new components, custom-made capacitors of its own design, new wiring and new connectors. An asymmetrical front panel pairs a large round volume knob, adjustable in 104 steps, with a 7-inch touchscreen. After switching on, the unit stays muted for a 40-second warm-up. Both chassis measure 480 x 178 x 394 mm, the audio unit weighing 10.7 kg and the supply 17.07 kg. It draws up to 235 W from 200 to 270 V AC, and 0.8 W in standby.

Pairing

Output polarity is non-inverting, and the minimum recommended load is 20 kohm with no more than 2000 pF of capacitance. RS-232 and an IR input are provided for external control. Warranty cover is three years on the electronics and 90 days on the valves.

Alternatives

The Audio Research Reference 6SE is a single-chassis line stage with four balanced and four single-ended inputs.