Audio Research LS28 Pre-Amplifier - Ex-Demonstration

Our beloved showroom demonstration Audio Research LS28 Pre-Amplifier is now ready to find a loving home. This is truly such a magical pre-amplifier and is renowned the world over. 

From Audio Research...

The LS28 line stage is a flexible and intuitive preamplifier. Four balanced and four single-ended inputs, and two sets of both balanced and single-ended outputs, allow maximum connectivity. The straightforward menu allows control of numerous parameters, including input naming, tube hours, auto shutdown, and home theater passthrough. Phase invert and mono are also standard functions. At the heart of the LS28 are four 6H30 vacuum tubes in the analog circuit. While the LS28 is the perfect match for any Audio Research amplifier, it has been designed to work with nearly any amplifier on the market today.

Since 1970, High Definition has been more than our trademark; it has been our guiding principle for all products. The Foundation Series continues this passion and philosophy, offering the listener stunning playback, great value, and unparalleled long-term support.

Condition: Light signs of showroom use, please contact us for further information or photos as necessary. 

Please Note:

All Ex-Demonstration, clearance and consignment sales are final. No refunds or exchanges will be given for change of mind, issues caused by product misuse or for problems or defects with the product that are disclosed.

Specifications

FREQUENCY RESPONSE

+0-3dB, 0.4Hz to 200kHz at rated output (Balanced, 200k ohms load)

DISTORTION (THD)

Less than .007% at 2V RMS BAL output

NOISE & HUM

Less than -100 dBv at maximum volume (103).

GAIN

Main output: 18.5dB Balanced output, 12.5dB SE output. Record out: 0dB (Processor input: 0dB BAL output).

INPUT IMPEDANCE

100K ohms Balanced, 50K ohms SE. Inputs: 4 balanced, 4 single-ended. Assignable processor passthrough.

OUTPUT IMPEDANCE

600 ohms Balanced, 300 ohms SE Main (2). 20K ohms minimum load and 2000pF maximum capacitance. Outputs (3): 2 main, 1 record out (XLR and RCA connectors).

OUTPUT POLARITY

Non-inverting

MAXIMUM INPUTS

16V RMS BAL, 8V RMS SE

RATED OUTPUTS

2V RMS (1V RMS SE) into 200K ohm balanced load (maximum balanced output capability is 17V RMS at less than 0.5% THD at 1kHz).

POWER SUPPLIES

Electronically regulated low and high voltage supplies. Automatic 45 sec. warm-up/ brown-out mute. Line regulation better than .01%.

TUBE COMPLEMENT

(4) 6H30P

POWER REQUIREMENTS

100-125VAC 60Hz (200-250VAC 50/60Hz) 130 watts. Standby: 2 watts.

OTHER

Dynamic Range: >122 dB (AES17). Crosstalk: -105dB or better at 1kHz. Controls: Rotary encoders: Volume (103 steps), Select Input. Push Buttons: Power, Menu, Enter, Mono, Invert, Mute.

DIMENSIONS

Width: 19” (48 cm). Height: 6.5” (13.7 cm). Depth: 13.7” (34.8 cm). Handles extend 1.6” (4 cm) forward of the front panel.

WEIGHT

15.9 lbs. (7.2 kg) Net; 24 lbs. (10.9 kg) Shipping.