The preamplifier is the heart of any high-performance audio system, the crucial component that routes signals, provides gain, and, most importantly, engages the listener. The Audio Research LS28SE is a line stage preamplifier that performs these duties with exceptional musicality, transparency, and control. As a Special Edition (SE) model, it inherits the latest component technologies and wiring from Audio Research's flagship Reference series, elevating its performance to a stunning new level. Built around a pure Class-A, all-tube analog circuit, the LS28SE delivers the holographic soundstage, rich tonal color, and dynamic realism that have made Audio Research a legend. It is the perfect, versatile, and user-friendly command center for the music lover who demands an immersive and emotionally profound connection to their music. Key Features Pure Class-A, All-Tube Circuit: The analog circuit features four 6H30 vacuum tubes in a pure Class-A, zero-feedback design for the most natural and musically engaging sound. Special Edition (SE) Upgrades: Incorporates the same proprietary gold coupling caps and special internal wiring found in the flagship Reference 6SE, resulting in dramatically improved resolution and transparency. Versatile Inputs and Outputs: A complete suite of connectivity, including four balanced (XLR) and four single-ended (RCA) inputs, plus two balanced and two single-ended outputs. Home Theater Pass-Through: A discrete, processor pass-through input allows for easy integration into a high-end home theater system without compromising two-channel performance. Intuitive Front Panel Control: A large, clear vacuum-fluorescent display and soft-touch buttons provide easy access to all functions, including input naming, tube hours, and auto shutdown. Robust, Regulated Power Supply: Features a low-noise R-core power transformer and a robust, highly regulated power supply for pure, stable power to all circuits. Built-in Tube Hour Meter: An integrated timer tracks the usage of the vacuum tubes, making it easy to know when it's time for a replacement set. Classic Audio Research Build: Housed in the iconic chassis with a brushed aluminum faceplate, custom-machined buttons, and sturdy handles, all handcrafted in Minnesota, USA. Full-Function Metal Remote: Includes a full-function metal remote control for complete command from the listening chair. The Power of "Special Edition" The "SE" designation signifies a profound upgrade, elevating the already superb LS28 to a new plane of performance. The LS28SE incorporates critical component technologies developed for Audio Research's flagship Reference series. The most vital signal paths now feature the same proprietary, custom-designed gold coupling capacitors and special internal wiring found in the REF6SE. This infusion of flagship DNA results in a dramatic improvement in resolution, a more refined and grain-free presentation, and a greater sense of dynamic immediacy. The soundstage becomes more focused and expansive, allowing you to hear deeper into the recording than ever before. The Heart of the Music: A Pure Tube Analog Stage The soul of the LS28SE resides in its analog circuit. This is where the signal is amplified and prepared for your power amplifier, and where the magic happens. Rejecting sterile, solid-state solutions, Audio Research has engineered a pure Class-A circuit with zero negative feedback, built around four 6H30 vacuum tubes. This hallmark design allows the LS28SE to produce a sound that is dynamically alive, harmonically rich, and dimensionally holographic. It delivers the kind of natural, fatigue-free presentation that encourages long, immersive listening sessions. The Flexible Command Center The LS28SE is designed to be the versatile heart of any high-end system. With a generous array of four balanced and four single-ended inputs, it can accommodate all of your sources with ease. You can even customize the input names on the clear front-panel display for intuitive operation. The inclusion of a discrete processor pass-through makes it simple to integrate the LS28SE into a sophisticated home theater system, ensuring you get reference-level two-channel performance without sacrificing multi-channel convenience. A Legacy of Craftsmanship The LS28SE is instantly recognizable as an Audio Research component, built to the same exacting standards the company has upheld for over 50 years. The robust chassis, with its classic brushed aluminum faceplate and substantial handles, is a testament to its "built-to-last" philosophy. Every component is meticulously assembled by hand in Minnesota, USA, undergoing rigorous testing and quality control at every stage. This is not a product designed for obsolescence; it is a handcrafted musical instrument, built to provide a lifetime of listening pleasure. The Listening Room Difference When you shop with The Listening Room, you get more than just gear. As a third-generation, family-run business with a passion for music and decades of experience, we offer personalized service that goes far beyond the sale. Call, text, or email, and you’ll get a real human who knows this equipment inside and out. From in-store demos to curated home system design and wide-radius delivery, we’re here to help you get the absolute best out of your purchase. Specifications Specification Details 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 Compliment (4) 6H30P dual triode Power Requirements 105-125VAC 60Hz (200-250VAC 50/60Hz) 130 watts maximum Standby 2W 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: 16.0 lbs. (7.2 kg) Net; 24 lbs. (10.9 kg) Shipping
