B&K SIMPLY BETTER! B&K Components, Ltd. ST125.3 ST125.2 ST125.
B&K Components, Ltd., 2100 Old Union Road, Buffalo New York 14227-2725 Phone 1-800-543-5252 or (716) 656-0026, Fax (716) 656-1291 E-mail: info@bkcomp.com Web: www.bkcomp.
TABLE OF CONTENTS Table of Contents ....................................................................................................................................................iii Safety Precautions .................................................................................................................................................. 1 Purpose and Function........................................................................................................................................
SAFETY PRECAUTIONS PLEASE READ BEFORE INSTALLING WARNING: to prevent fire or shock hazard, do not expose this unit to rain or moisture. Care should be taken to prevent objects or liquid from entering the enclosure. Never handle the power cord with wet hands. • The lightning flash with arrowhead, within an equilateral triangle, is intended to alert the user of the presence of uninsulated “dangerous voltage” within the product’s enclosure that may constitute a risk of electric shock to you.
PURPOSE AND FUNCTION The ST125.3 (three channel), ST125.2 (two channel) and ST125.1 (mono) are high power amplifiers that are designed for use in all types of audio or audio/video systems. DESIGN AND CONSTRUCTION The ST125.3, ST125.2 and ST125.1 amplifiers utilize high quality electronic circuitry to achieve an environment wherein a detailed, transparent, and highly musical sound can be realized.
REAR PANEL * 7 8 6 * 5 * CONTROL I/O CONTROL IN ALLOWS AMPLIFIER OPERATION WHEN A 5-24V SIGNAL IS APPLIED WITH A 3.
LEVEL ADJUSTMENT Generally in a home theater application, volume level is controlled by the A/V surround processor. In a system for use with the ST125.3, ST125.2 or ST125.1, adjustment of the volume level must be performed using the external preamplifier/processor. INPUTS The ST125.3, ST125.2 or ST125.1, allows signal patch cables (interconnects) to be sourced from either balanced or unbalanced line level preamplifier/processor outputs.
BALANCED OR UNBALANCED CONNECTIONS Shown below are typical preamplifier to amplifier connections: RCA Unbalanced Connections FRONT LEFT CHANNEL 2 INPUT C L CHANNEL 1 INPUT FRONT CENTER XLR (BALANCED) FRONT RIGHT CHANNEL 3 INPUT R XLR (BALANCED) B&K XLR (BALANCED) S I M P LY B E T T E R ! RCA INPUT XLR INPUT RCA INPUT RCA (UNBALANCED) XLR INPUT RCA INPUT RCA (UNBALANCED) XLR INPUT RCA (UNBALANCED) OR CHANNEL 1 INPUT CHANNEL 2 INPUT CHANNEL 3 INPUT XLR (BALANCED) XLR (BALANCED) XLR
OUTPUTS Five way binding posts are provided. There is one pair provided for each channel. They are designed to accept a banana-type plug, spade-lug connector (shown below), terminal posts, and bare wire, and they are color coded for easy identification. The positive (+) post should always be connected to the speakers (+) jack. The negative (-) post should always be connected to the speakers (-) jack.
SYSTEM INSTALLATION There will most likely be a number of cables involved in the installation of your home entertainment system. Preplanning is essential in order to maximize system efficiency. We recommend the following as a means of helping you reach that goal. Make a diagram of your proposed system by laying out the relative location of each component in the system. Then lay out the proposed cable runs between them. Number each cable and record its length on the diagram for future use.
CONTROL INPUT AND OUTPUT A control (trigger) system is provided on the ST125.3, ST125.2 and ST125.1 amplifiers to allow remote switching of the amplifier’s standby on/off feature. The control input is designed to operate with a source (trigger) of 5-24 volts AC or DC. All B&K A/V processors and preamplifiers may easily be utilized to control this standby on/off feature.
TROUBLESHOOTING PROBLEM POSSIBLE CAUSE POSSIBLE SOLUTION No sound (‘on’ LED not illuminated) 1. Power cord not plugged in. 2. Power off at AC source. 3. AC power inlet fuse blown or faulty 4. Control Input not activated. 1. Reconnect power cord. 2. Check AC switch or fuse 3. Check for shorts or overloading 4. Supply Control IN with a 5-24 Volt AC or DC supply (Page 8) No sound on some or all selected channels (‘on’ LED illuminated) 1. Speaker leads loose or faulty 2.
SPECIFICATIONS Power Rating: 8 ohms - ST125.3/ST125.2/ST125.1 4 ohms - ST125.3/ST125.2/ST125.1 140/140/170 watts @ 1 kHz 185/185/225 watts @ 1 kHz THD (S+N) 0.09 % @ 1 kHz Frequency response 5 Hz – 45 kHz Input sensitivity RCA unbalanced 1.4 Volts Input sensitivity XLR balanced 2.8 Volts Pin 1 = Gnd, 2 = In +, 3 = In - Input impedance 33.2 k ohms Damping factor - ST125.3/ST125.2/ST125.1 100/100/180 Current (peak to peak) - ST125.3/ST125.2/ST125.
LIMITED WARRANTY B & K Components Ltd., referred to herein as B & K, warrants your B & K equipment against all defects in material and workmanship for a period of five years from the date of purchase. This warranty applies only to the original purchaser and only to equipment in normal residential use and service.
FUSE XLR INPUT 12 + PLUS - MINUS S FU E RCA (UNBALANCED) XLR INPUT + PLUS - MINUS CHANNEL 2 OUTPUT RCA INPUT F US AC LINE SERIAL # S FU E RCA (UNBALANCED) F US CHANNEL 1 OUTPUT RCA INPUT S FU E RCA (UNBALANCED) + PLUS - MINUS B&K S I M P LY B E T T E R ! www.bkcomp.com Made in the U.S.A. B&K Components, Ltd.
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