B & K Components, Ltd. User Manual REFERENCE 125.
ii USER MANUAL - REFERENCE 125.2 © 2004 B & K Components Ltd. All rights reserved. The information in this manual is copyright protected. No part of this manual may be copied or reproduced in any form without prior written consent from B & K Components, Ltd. B & K Components Ltd. SHALL NOT BE LIABLE FOR OPERATIONAL, TECHNICAL OR EDITORIAL ERRORS/OMISSIONS MADE IN THIS MANUAL. The information in this manual may be subject to change without prior notice. Accessories Included 1 1 1 1 - Reference 125.
1 TABLE OF CONTENTS ACCESSORIES AND LIMITED WARRANTY ii TABLE OF CONTENTS 1 SAFETY PRECAUTIONS 2 PURPOSE AND FUNCTION 3 BACK PANEL 4 INPUTS 5 INPUT/OUTPUT CONNECTIONS 6 SYSTEM INSTALLATION 7 CONTROL TRIGGERS 8 TROUBLESHOOTING 9 SPECIFICATIONS Back Cover Product Information Date of Purchase: Amp Model #: Amp Serial #: Purchased From: Address: Phone #:
2 SAFETY PRECAUTIONS Installation Considerations CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN 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.
PURPOSE AND FUNCTION PURPOSE AND FUNCTION The Reference 125.2 S2 (Two channel) is a high power amplifier that is designed for use in all types of audio or audio/video systems. DESIGN AND CONSTRUCTION The Reference 125.2 S2 amplifier utilizes high quality electronic circuitry to achieve an environment wherein a detailed, transparent, and highly musical sound can be realized.
4 BACK PANEL 7 CHANNEL 1 INPUT CTRL IN XLR (BALANCED) RCA INPUT XLR INPUT US SE F U CHANNEL 1 OUTPUT CHANNEL 2 OUTPUT S IMPLY B ETTER! SERIAL # POSITIVE POSITIVE N E G AT I V E N E G AT I V E RISK OF ELECTRIC SHOCK DO NOT OPEN AC LINE 1 B&K U SE F US EF RCA (UNBALANCED) U C AU T I O N : F O R C O N T I N U E D PROTECTION AGAINST RISK O F F I R E R E P L A C E O N LY W I T H S A M E T Y P E A N D R AT I N G . XLR INPUT RCA INPUT RCA (UNBALANCED) EF FUSE XLR (BALANCED) www.
5 INPUTS INPUTS The Reference 125.2 S2 allows signal patch cables (interconnects) to be sourced from either balanced or unbalanced volume level preamplifier/processor outputs. A switch is used to configure a SINGLE AMPLIFIER CHANNEL for use with either a balanced (XLR) or unbalanced (RCA) output. CHANNEL 1 INPUT XLR (BALANCED) RCA INPUT XLR INPUT RCA (UNBALANCED) XLR BALANCED There are two balanced input connectors on the Reference 125.2 S2.
6 INPUT/OUTPUT CONNECTIONS Use either RCA unbalanced or XLR balanced to connect the preamplifier to amplifier. RCA Unbalanced Connections FRONT LEFT FRONT RIGHT CHANNEL 1 INPUT CHANNEL 2 INPUT H i g h Pe r f o r m a n c e Audio/Video Systems Hand-Made in the U.S.A. L XLR (BALANCED) B&K R XLR (BALANCED) S I M P LY B E T T E R ! www.bkcomp.
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. • When possible, use a dedicated AC power line for the amplifier, one that is not shared by any other household component.
8 CONTROL TRIGGERS A control (trigger) system is provided on the Reference 125.2 S2 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 DC. All B & K A/V processors and preamplifiers utilize control output triggers to easily integrate an amplifier into an audio system.
TROUBLESHOOTING PROBLEM No sound (power 'on' LED not illuminated). POSSIBLE CAUSE 1. Power cord not plugged in. 2. Power off at AC source. 3. AC power inlet fuse blown or faulty. 4. Control voltage not activated. 5. Power switch in off position (out). POSSIBLE SOLUTION 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 DC supply (Page 8). 5. Push in power switch. No sound on some or all 1. Speaker leads loose or faulty.
SPECIFICATIONS REFERENCE 125.2 S2 Power Rating: 8Ω Power Rating: 4Ω 125 watts 185 watts Number of Channels 2 Current (peak to peak) 30 Amps Dynamic Headroom 1.2 dB Total Harmonic Distortion (THD) 0.09 % Signal to Noise (S/N) 95 dB Input Impedance 33.2 kΩ Damping Factor (50 Hz) 180 Frequency Response 5 Hz - 45 kHz Slew Rate 14 V / µsec Input Sensitivity RCA Unbalanced 1.0 Volt Input Sensitivity XLR Balanced 2.8 Volts | Pin 1 = Gnd | Pin 2 = In + | Pin 3 = In - Gain 28.
