LS28SE

Audio Research is one of the most revered brands in the world of high-end amplification. It is one of the top brands for those looking for valve amplifiers and is best known for producing functional if not luxurious amplifiers. Founded in 1970 in Minneapolis, Audio Research is one of the oldest manufacturers in high-end American audio.

The company was one of the drivers in high-end audio and helped shift the focus of the audio industry from designing products for the sake of new technology and the mass market to musical performance. Audio Research products have also become known as collector items and they hold on to their residual value unlike a lot of other brands.

Audio Research products are famous for their sound quality, consistency, longevity and serviceability. If you’re looking for best in class amplification that will stand up to the test of time then Audio Research is hard to beat. Check out the selection of integrated amplifiers, phono, pre-amp and power amplifiers below and for any questions get in touch with us on 01865 790 879.

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

THD+NOISE
Less than .007% at 2V RMS BAL output.

NOISE
Less than -100dBv at max volume (103).

DYNAMIC RANGE
122dB (AES17).

CROSSTALK
-105dB

GAIN
Main output: 18.7dB balanced output. (9.3dB SE output.) Record output: 0dB (Processor input: 0dB balanced out).

INPUT IMPEDANCE
100K ohms Balanced, 50K ohms SE. 8 Inputs – 4 balanced, 4 single-ended.

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

OUTPUT POLARITY
Non-inverting.

MAXIMUM INPUT
16V RMS BAL, 8V RMS SE.

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

CONTROLS
Rotary volume selector (103 steps) and rotary input selector. Push buttons: Power, Menu, Enter, Mono, Invert, Mute

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 dual triode.

POWER REQUIREMENTS
105-125VAC 60Hz (200-250VAC 50/60Hz) 130 watts maximum.

STANDBY
2W

Further Information
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.