AUDIO RESEARCH REFERENCE 210

Pre owned. In good condition. Shows some signs of wear. Includes remote control, original packaging not included.

The Reference 210 features a familiar yet distinctive design, with a fully enclosed chassis and a thick front panel of the same dimensions as the VT100 and VTM200, enhanced by a vacuum-fluorescent display similar to those on the REF3 and REF610T. The chassis, 19½" deep plus handles, houses an internal structure similar to the 150M, with a one-piece ventilated cover wrapping the top and sides; the front panel is available in Natural or Black finishes.

The vacuum-fluorescent display shows the same information as the REF610T and is fully controlled via the remote: six brightness levels plus off, bias measurements for each output tube, AC line voltage, logarithmic power output up to 200 watts, and total tube operating hours. The internal layout has been completely redesigned, with the main circuit boards mounted horizontally instead of vertically. Transformers are mounted on a raised central channel running front to back; on one side is a board containing all audio stages, and on the other side a board with the power supply, resulting in a clean and harmonious layout. A small 12V Papst fan mounted on the rear panel provides low-speed airflow across the audio stages whenever the amplifier is powered on.

Continuous power output is 210 watts. Like the REF610T, the REF210 uses a fully balanced push-pull tube circuit in partial cathode-coupled mode, with three matched pairs of 6550C output tubes. Two 6550C driver tubes each control three output tubes in unison. The input stage uses direct-coupled JFETs followed by a 6N1P tube gain stage. Biasing is simple, with only two adjustment points.

The power supply features an energy storage of 787 joules, three-quarters that of the REF610T and significantly higher than the 448 joules of the REF300MKII. It shares proprietary coupling capacitors and extensive film-cap bypassing of all electrolytics with the REF610T. The input stage is tube-regulated with six additional solid-state regulators, and rectification is solid-state with a total of seven regulators. The massive custom output transformer offers ultra-wide bandwidth, with a response from 0.5 Hz to 240 kHz (-3 dB). Fifty percent cathode coupling of the output stage to the transformer ensures higher efficiency and better sound than conventional pentode or triode operation.

The input is balanced only, while the output provides dedicated taps for 4, 8, and 16-ohm speaker loads. Power is supplied via a 20A IEC connector, and unlike the REF610T, the REF210 includes a 12V trigger for remote turn-on.

Sonically, the Reference 210 is extraordinary in every aspect: detail resolution is stunning, with vivid, lifelike transparency that immerses the listener in the performance. Musicians appear with real body, weight, and presence, not as flat images. The soundstage is wide and boundless, with palpable space and air, while dynamic nuances and crescendos unfold naturally. Bass impact, speed, and articulation are revolutionary, leaving a lasting impression on the listener.

Technical specifications:

• Power output: 210 watts per channel continuous from 20 Hz to 20 kHz; typical THD 0.5% at 210 watts, below 0.02% at 1 watt; approximate power at clipping 240 watts (1 kHz)
• Power bandwidth: 10 Hz – 150 kHz (-3 dB)
• Frequency response: 0.5 Hz – 240 kHz (-3 dB at 1 watt)
• Input sensitivity: 1.7 V RMS balanced for rated output; 27 dB gain into 8 ohms
• Input impedance: 200k ohms balanced
• Outputs: 4, 8, and 16 ohms
• Output regulation: approx. 0.6 dB from load to open circuit
• Overall negative feedback: 12 dB
• Damping factor: approx. 14
• Slew rate: 40 V/µs
• Rise time: 1.2 µs
• Hum & noise: less than 0.3 mV RMS; 106 dB below rated output (IHF-A weighted, input shorted, 16-ohm output)
• Power supply energy storage: approx. 787 joules
• Power requirements: 105–130 VAC 60 Hz; 260–250 VAC 50 Hz; 680 watts at rated output; 950 watts maximum; 380 watts at idle; 0.15 watts off
• Tubes: 3 matched pairs 6550C power output; 1 matched pair 6550C driver; 2 x 6N1P gain stage and regulator driver; 1 x 6550C regulator
• Dimensions: 48.3 cm (W) × 22.2 cm (H) × 49.5 cm (D); handles extend 3.8 cm
• Weight: 33.6 kg net