User Guide SP20 Stereo Preamplifier H I G H D E F I N I T I O N®
Contents Preface 3 Illustrations 4 Warnings 5 Installation Installation of Vacuum Tubes 6 In Your System 7 Connections 8 Operation Power-Up Procedure 9 Front Panel Controls 10 Remote Control Only Controls 11 Interactive Touch Screen Operation 12 - 17 Troubleshooting 18 Maintenance Servicing 19 Cleaning 19 Disposal and Recycling Guidelines 19 Limited Warranty 20 Specifications 21
Preface Thank you for selecting the SP20 as part of your music listening system. The engineers and designers at Audio Research have spent countless hours of listening and testing to create a preamplifier of the highest caliber for music reproduction. The SP20 has been designed to provide you many years of playback. Please take a few minutes to read through this guide to help you better understand and optimize your new preamplifier.
Illustrations Front Panel SOURCE POWER VOLUME SP20 VACUUM TUBE STEREO PREAMPLIFIER HIGH DEFINITION MUTE ® PHONES SPKR OFF Back Panel RIGHT INPUTS MODEL SP20 RIGHT OUTPUTS RS-232 IR INPUT STEREO PREAMPLIFIER PLYMOUTH, MINNESOTA MADE IN U.S.A.
Warnings To prevent fire, or shock hazard, do not expose your SP20 to rain or moisture. Do not place containers with liquid on top of unit. This unit contains voltages which can cause serious injury or death. Do not operate with cover removed. Refer servicing to your authorized Audio Research dealer or other qualified personnel. The detachable power cord on your SP20 is equipped with a heavy gauge, 3-conductor cable and a standard three-prong grounding plug.
Installation Installation of Vacuum Tubes Before operating the SP20... This unit has been shipped with the vacuum tubes installed in protective foam in a separate box packed inside the shipping carton. Remove the tubes carefully from the protective foam. Using a phillips-head screwdriver to loosen the fastening screws, remove the top cover and set aside.
Installation In your System While the SP20 does not dissipate an unusual amount of heat, it is important that it be provided with reasonable airflow to assure long, trouble-free operation. In addition, the following installation guidelines will help insure maximum sonic performance as well as reliable service: Operate unit in upright and horizontal position, preferably on solid, nonmetal shelving.
Connections Analog Connections Input Connectors: The SP20 provides five pairs of single-ended input connectors: SE1 - 4, PHONO and MONITOR. Please note that input SE4 can be selected as a unity gain input; in this case, SE4 should only be connected to a component with a volume control (such as a home theater processor). For further information about the SE4 unity gain (PROC mode), see the section ‘PROC Mode’ on page 16. In addition, there are two pairs of balanced input connectors: BAL1 and BAL2.
Operation Power-Up Procedure • Secure all rear-panel connections between SP20, power amplifier(s) and input sources. • Plug three-prong power cord from rear of chassis into grounded A.C. wall outlet. The Power switch defaults to ’off’ when the unit is plugged into a power receptacle. • Press power switch (either on the remote or front panel). The screen will begin the warm-up sequence, first displaying the Audio Research logo, followed by SP20 and a series of dots (fig. 1 + 2).
Operation Front Panel Controls The SP20 has two microprocessor-driven rotary controls and three buttons (Power, Mute and Speaker Off). Left Rotary control (Input Select): Select input by rotating the control to the left or right. The screen displays the current input by factory-set and user-definable name at the top right. Right Rotary control (Volume): Adjust volume (output level) up or down for both L and R channels.
Operation Remote Control only Functions Input Buttons: Allows direct selection of each of the 7 inputs of the SP20. Please note that input SE4 is user-selectable to function as a unity gain (processor) input. When engaged and SE4 is selected, ‘Unity Gain’ will appear in the display and the volume control will be defeated. Before selecting the unity gain input, be sure to turn down the volume on your connected processor/source. BAL/SE: Select as appropriate for each input.
Operation Interactive Touch Screen Operation The SP20 has been designed with a 4.3” interactive touch screen for reliable and easy usage. The interface is programmed to be as intuitive and straight-forward as possible. Please review the following section to get the most from your preamplifier. The Home Screen The Home Screen provides the current status and operating functions of the SP20. Once you have set up the preamplifier, the Home Screen will be the most used interface for operating your system.
Operation 2 Monitor Indicates when the Monitor input is selected. To select the monitor input, touch anywhere in the input name area of the screen, or push the monitor button on the remote. 3 Volume The large green number in the top right corner shows the master volume. The volume range is from 0-103. Set volume levels can be programmed so that when the SP20 is initially powered on, the volume is always at the same number.
Operation In the following explanations, the icon(s) associated with the function are shown in the left column. 8 Balance L 0 The Balance control adjusts the output from center position to the left or right channels. To adjust balance, touch the balance icon and the balance slider will appear in the space above it.
Operation Settings Menu or 15
Operation Settings Menu The features of the settings menu allow you to control certain parameters as well as customize aspects of the SP20. The following section will explain each component of the settings menu and explain their function. Tube Hours: The Tube Hours displays the total number of hours the SP20 has been running. This is useful to gauge tube life and prepare for eventual replacement.
Operation theater processor. To engage the PROC mode, simply touch the label. A red ‘Confirm’ button will appear beneath the PROC mode button; touch it to turn on (or off) the unity gain setting. When engaged the PROC Mode button will display ‘On’. System: The System submenu allows you to set volume presets for each of the two outputs of the SP20, check the software version, and set the unit back to factory defaults.
Operation Troubleshooting It is possible for a static discharge to temporarily disable the microprocessor that allows the controls to function. If this should occur, depress the ‘Mute’ button, then turn off the preamp and unplug the preamp from the A.C. receptacle for 60 seconds. Reconnect the A.C. plug and turn the preamp back on, along with other components. The controls should resume normal operation. If the problem persists, contact your dealer or Audio Research Customer Service at 763-577-9700.
Maintenance Servicing CAUTION: Your SP20 contains sufficient levels of voltage and current to be lethal. Do not tamper with a component or part inside the unit. Refer any needed service to your authorized Audio Research dealer or other qualified technician. The vacuum tubes inside your SP20 are quality tubes and with normal use should not need to be changed for approximately 4,000 hours of use. Replacement tubes should be of equivalent quality and are available from Audio Research.
Limited Warranty Audio Research Corporation products are covered by a 3-Year Limited Warranty, or a 90-Day Limited Warranty (vacuum tubes). This Limited Warranty initiates from the date of purchase, and is limited to the original purchaser, or in the case of demonstration equipment, limited to the balance of warranty remaining after original shipment to the retailer or importer.
Specifications Frequency Response: Line: ± 0.3dB 2 Hz to 80 kHz; -3dB 0.8Hz to 220 kHz Phono: ± 0.1dB of RIAA 10Hz to 20kHz; ± 0.4dB 5Hz to 80kHz Headphone: ± 0.05dB 20Hz to 20kHz; -3dB 0.8Hz to 220kHz THD+N: Line: < .003% at 2V RMS, Bal output Phono: < .005% at 3V RMS output, to Record output Headphone: < .009% at 1V RMS output Gain: Line: 13.8dB, Processor: 0dB Phono: 58dB @ 1KHz to Record output Headphone: 11.3dB Noise: Line: <-101dBV volume at max.
H I G H D E F I N I T I O N® www.audioresearch.com Specifications subject to change without notice. ©2013 Audio Research Corporation.
