The Audio Research I/50 Integrated Amplifier is available in 6 colors with optional DAC and Phono modules, which is how the review sample is outfitted and dressed in Gold, offering 50Watts of output power from 2 pair of JJ 6550WE vacuum tubes.
The Phono module provides 42 dB of gain making it compatible with moving magnet and high-output moving coil cartridges, while the optional DAC module offers USB (supports PCM resolutions up to 384kHz and DS128), Toslink, and Coax inputs as well as Bluetooth for convenience. There’s a total of three line level inputs (2x RCA, 1x XLR) and speaker binding posts with 4 and 8 Ohm taps.
Joining the two matched pairs of JJ 8550s are three 6922s (1x input, 2x driver) and for a fun visual treat a pair of AR’s LexieTubes that light up with a start up count down and, once warm, volume level and active input. A 1/4″ headphone jack also sits on the high gloss black top panel along with the power button, volume and input select knobs. A wafer thin metal remote is included.
The I/50 is built at Audio Research’s Minnesota HQ and the aluminum top plate surround has a Cerakote ceramic finish that comes in Gold, Natural, Red, White, Black, and Blue. Color is good.
Audio Research was founded by William Zane Johnson in 1970 (!) and they have built their fair share of classic gear including the D150 amplifier (1975) and SP10/SP-10PS pre/power combo (1982). The company was recently acquired and is running smoothly so I am especially thrilled at the opportunity to spend time with the I/50.
Audio Research I/50 Integrated Amplifier
Price: $5500, Phono Module +$750, DAC module +$1000
Company Website: Audio Research
Specifications
Power Output: 50 watts continuous from 20Hz to 20kHz. 1kHz total harmonic distortion typically 1% per channel, below 0.1% at 1 watt (Note that actual power output is dependent upon both line voltage and “condition” i.e.: if power line has high distortion, maximum power will be affected adversely, although from a listening standpoint this is not critical)
Power Bandwidth: (-3dB points) 10Hz to 22kHz
Frequency Response: (-3dB points at 1 watt) 7Hz to 30kHz
Input Sensitivity: 1.25V RMS for rated output.
Input Impedance: 100K ohms Balanced, 48K ohms Single Ended
Output Polarity: Non-inverting. Balanced input pin 2+ (IEC-268)
Output Taps: 8 ohms, 4 ohms
Power Requirements: 105-130VAC 60Hz (210-250VAC 50Hz) 252 watts at rated output.
Tubes Required: 2 matched pair 6550WE; 3-6922 (1 input, 2 driver).
Dimensions:
Width 16.5” (42 cm)
Height 7.25” (18 cm)
Depth 13.5” (34 cm)
Weight: 40 lbs (18.1 kg); 51 lbs (23.1kg) shipping weight.