LS28
Discontinued replaced by Audio Research LS28SE
Inspired by the lauded Reference 6, the LS28 can musically transform the nest audio system.
Flexible and intuitive, the LS28 offers a remarkable level of performance in its price range.
Dynamics, clarity, and a transparent, three-dimensional presentation is a given, yet the larger power supply and redesigned circuitry in the LS28 offers much more than its predecessor.
Audio Research’s sensational sound is only one part of the Audio Research legacy, which their customers and the world’s most demanding critics agree upon. Their commitment to excellence is unparalleled.
The LS28 tube compliment has increased to four 6H30 tubes, the new R-core transformer is larger, and the larger power supply provides more current.
Volume control circuitry has been revamped for better sound and greater functionality. Even the circuit board material has been improved.
Fully balanced, Class-A, with a single gain stage and zero feedback, the LS28 is a flexible performer, providing eight inputs, four each balanced and unbalanced.
There are three sets of outputs, two Main and one Record, all with balanced and single-ended connections. 12V triggers and an RS232 port allow it to be used in the simplest or the most complex systems.
With its supplied remote, most of the LS28’s functions can be controlled from your listening chair.
The LS28 is extremely transparent, providing a presentation that is holographic and dynamically alive, with great resolution. Voices and instruments are reproduced with texture and weight, with the ability to leave you breathless by their melodic expressiveness.
After nearly 50 years, Audio Research’s focus remains the advancement of the state-of-the-art in music reproduction.
Every component is meticulously hand-crafted and personally auditioned before it leaves their factory.
Attention to detail, customer service, and product support create unprecedented value.
An Audio Research component is more than a purchase, it’s an investment.
Specifications LS28
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: 18.5dB balanced output. (12.5dB 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) 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
The company occupies a 48,000 square-foot, technically-advanced production plant and administrative headquarters in Maple Grove, Minnesota, where approximately 50 technical, assembly and support staff guide the product line from concept to finished goods.