Audio Research LS28SE Line Stage Preamplifier

The improvements in the LS28SE stem from what was learned during the creation of Audio Research’s Reference 160-series amplifiers. Very similar to the wire and parts changes incorporated in the REF6SE and REF PH3SE, the LS28SE also includes upgrading to the same proprietary gold coupling caps used in the REF6SE. These numerous and costly component upgrades elevate the LS28SE’s performance to an entirely new level. The improved clarity, resolution, transient snap, sense of space, and a relaxed purity are instantly noticeable and will inspire extended listening sessions.

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.

Technical Specifications:

• 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
• 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.

We endeavour to despatch same day for orders placed up to 1pm on available stock items (items with stock message "Usually dispatched within 24 hours"). Please remember to check with us first for a physical stock check if next day delivery is important to you. Any items with stock message "Usually dispatched within 72 hours" are items that we do not hold in stock but order in from the importer or manufacturer as soon as a customer order is received. Occasionally these may be delayed beyond 72 hours due to importer/manufacturer stock levels but we will inform you as soon as we can if this is the case.

UK Orders

We despatch the bulk of our UK mainland items on a 24 hour service – Free of Charge.  Non Mainland locations - Isle of Man, Isle of Wight, the Scilly Isles, the Scottish highlands and Islands, the Channel Islands and Northern Ireland may take a day or so longer and are not Free of Charge. Smaller items are delivered using Royal Mail 24 or special delivery. Larger items are delivered using a courier service such as DPD or UPS.

International Orders:

Due to the nature of our products and brand restrictions we are only able to send certain items internationally. Smaller items are delivered using Royal Mail Small Packets Airmail with International Tracked and/or Signed depending on value of item and availability of the service. Larger International shipments are sent by insured and tracked services using UPS. If there are any delays due to specific customs regulations, etc, you will be contacted by Hifisound or by the courier with a request for any further information required. Customs duties can apply for shipments to any countries outside of the UK depending on where the product you have bought is made. Customers are responsible for all taxes and duties incurred when the items enter their country.

Collect in Store or Home Install

At the request of the manufacturer some items cannot be supplied by mail order but you can click and buy them and then elect to collect them from our store or arrange a home install (if applicable). Applicable items clearly state that they are Collect in store or home install. Once ordered you will receive a message prompting you to contact us by phone or email to arrange for us to deliver and install or to reserve and collect from our store at your convenience, you will also be advised of the delivery time / stock availability as not all Home install / collect in store items are held in stock.