The VSi75 integrated amplifier breaks new ground in an ‘all in one’ product design, and sets a new benchmark in the lifelike reproduction of music. The VSi75 continues the design series of ‘open chassis’ products from Audio Research such as the VSi60 and VS115, yet incorporates new developments from the Reference series product to combine in a visually striking and sonically astonishing product. The VSi75 springboards from the award-winning VSi60 and takes the listener to new plateaus of musical enjoyment. While similar in form to the ’60, the chassis has been reworked and refined to reflect the industrial design for which Audio Research is known: the front panel reflects those on full-size components, the perforated cover hearkens back to earlier Audio Research products, and the chassis is a sealed, monochromatic silver to match with the rest of the components. The front panel sports a new LCD display which clearly displays input, volume and other functional information.

Performance-wise, the VSi75 is in an entirely different league for a number of reasons. It has a new power transformer that was designed around the KT150 output tube. The VSi75’s wide bandwidth output transformers are the same as those in the remarkable Reference 75, and we also incorporate some key REF75 parts including proprietary coupling caps. And, we doubled the bulk power supply caps.

The resulting sound from these cumulative improvements is striking, with tremendous resolution of detail, silky and extended highs, surprising weight and authority, and the ability to develop an immense sound stage. The VSi75 sounds very much like the amp from which it borrows, the REF75, with an immediacy, delicacy and focus that are captivating. Couple it with a deserving source like the REFCD9 for a euphoric experience.

POWER OUTPUT

75 watts per channel continuous from 20Hz to 20kHz. 1 kHz total harmonic distortion typically 1.5% at 75 watts, .05% at 1 watt. Approximate actual power available at “clipping” 80 watts (1kHz). (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 very critical.)

POWER BANDWIDTH 

(-3dB points) 12Hz to 70kHz.

FREQUENCY RESPONSE

(-3dB points at 1 watt) 1.0Hz to 70 kHz.

INPUT SENSITIVITY

0.55V RMS Single-ended for rated output. (32.5dB gain into 8 ohms.)

INPUT IMPEDANCE 

52.5K ohms Single-ended.

INPUTS 

(5) 1, 2, 3, 4, 5 (Single Ended RCA connectors).

MAXIMUM INPUT 

10V RMS (any input).

OUTPUT POLARITY

Non-Inverting (any input).

PUSH BUTTONS

Volume up, Volume down (103 steps), Power, Input, Mute, Bias. All functions on IR remote control.

OUTPUT REGULATION 

Approximately 2dB 8 ohm load to open circuit (Damping factor approximately 4).

OUTPUT TAPS

8 ohms, 4 ohms.

OVERALL NEGATIVE FEEDBACK 

4dB.

SLEW RATE

10 volts/microsecond.

RISE TIME

4 microseconds.

HUM & NOISE

Less than 1.0 mV RMS -88dB below rated output (IHF weighted, Vol down).

POWER SUPPLIES

Electronically regulated Low and High voltage supplies for input stages. Automatic 40 sec. warm-up/brown-out mute.

POWER SUPPLY ENERGY STORAGE

Approximately 350 joules.

POWER REQUIREMENTS 

100-125VAC 60Hz (200-250VAC 50Hz) 400 watts at rated output, 600 watts maximum, 210 watts at “idle’ 1.0 watt power off.

TUBES REQUIRED

2-Matched pair KT150-Power Output; 2 -6H30 driver.

DIMENSIONS 

Width 14.5” (36.8 cm); Height 9.25” (23.5 cm); Depth 16.25” (41.3 cm); Rear connectors extend .88” beyond chassis.

WEIGHT 

36.4 lbs. (16.5 kg) Net; 49.3 lbs. (22.4 kg) Shipping.