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PURPOSE AND FUNCTION

PURPOSE AND FUNCTION

The Reference 125.5 S2 (Five channel) or Reference 125.7 S2 (Seven 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 125.5 S2 or Reference 125.7 S2 amplifier utilizes high quality electronic circuitry to achieve an environment wherein a detailed, transparent, and highly musical sound can be realized. The high quality parts complement includes: state-of-the-art solid state devices, 1% metal film resistors, computer grade elec- trolytic power supply capacitors, and a high capacity toroidal transformer. All B&K products are designed and hand assembled in Buffalo, NY U.S.A.

The Reference 125.5 S2 or Reference 125.7 S2 operates with a class A predriver and AB MOSFET power output stages. These high power amplifiers are capable of delivering full range while reproducing the most demanding music passages effortlessly into the most demanding audiophile speakers.

FEATURES

High Current - Ability to cleanly, accurately, and reliably reproduce demanding recordings or source materials into low impedance drivers and speaker systems.

Class A Predriver - Improves low level detail and clarity for smoother, more musical sound.

AB MOSFET Output - Provides efficient and linear power delivery, as well as protection from thermal overload. Gold Plated Connectors - Improved sound with minimum signal loss and degradation.

Five Way Binding Posts - High quality binding posts accommodate up to 4 gauge wire.

Control Output - One 3.5mm (1/8”) 10-12 VDC @ 200 mA output for controlling other amplifiers or control- ling external systems that use a voltage trigger.

Control Input - One 3.5mm (1/8”) jack that allows standby on/off with a 5-24 VDC control signal.

Toroidal Transformer - Efficient, high current, shielded transformer that supplies the amplifier with a clean and constant supply of power, even during highly demanding source material passages.

Discrete Circuitry - Dynamically provides a full, accurate, and three dimensional reproduction of source material.

1% Metal Film Resistors - High quality resistors used in all active circuitry to reduce noise and obtain better sound purity.

Computer Grade Capacitors - Large capacity computer grade electrolytic capacitors for extended low fre- quency control, increased power supply, and improved dynamics.

Balanced Inputs - Balanced inputs deliver the quietest and most accurate signal path between the preampli- fier and amplifier.

Full Power Operation - Capability to operate at full power with a square wave input.

Differential Input Stage - A current source load assures DC stability and wide bandwidth linearity.

5 Year Factory Warranty - All B&K products sold through an authorized dealers are covered by a 5 year parts and labor factory Warranty.

Available Faceplates

17” Black (Standard)

17” Silver (Optional)

19” Black Rack Mount (Optional)

19” Silver Rack Mount (Optional)

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B&K 125.7 S2, 125.5 S2 user manual Purpose and Function, Design and Construction, Features
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125.7 S2, 125.5 S2 specifications

The B&K 125.7 S2 and B&K 125.5 S2 are part of the renowned Bowers & Wilkins speaker series, celebrated for their exceptional audio quality and innovative technologies. These speaker models are designed for both audiophiles and casual listeners who crave an immersive sound experience in their home environments.

The B&K 125.7 S2 features a 3-way design, incorporating a 1-inch aluminum dome tweeter, a 5-inch Kevlar midrange driver, and two 7-inch paper bass drivers. This configuration ensures rich, detailed highs, a clear midrange, and powerful low frequencies, delivering a balanced sound signature that excels across various musical genres and listening scenarios. The speaker's frequency response ranges from 45 Hz to 20 kHz, providing a wide soundstage that captures both subtle nuances and dynamic peaks in audio playback.

Equipped with the latest Bowers & Wilkins technologies, the B&K 125.7 S2 utilizes the advanced Flowport technology, which minimizes turbulence and enhances bass output. This innovation allows for cleaner, more precise low-frequency reproduction, making it ideal for both music and movie soundtracks. Additionally, the tweeter's decoupled design reduces distortion, ensuring that high-frequency details are reproduced accurately.

On the other hand, the B&K 125.5 S2 is similarly built but features a slightly compact design, making it an excellent choice for smaller spaces or more discreet setups. It encompasses a 2-way configuration that includes a 1-inch aluminum dome tweeter paired with a 5-inch Kevlar midrange driver. While it lacks the additional bass drivers found in the 125.7 S2, the 125.5 S2 compensates with an impressive frequency response of 50 Hz to 20 kHz, delivering a punchy and engaging audio experience.

Both models are crafted with premium materials, including an elegantly finished cabinet that not only enhances their aesthetic appeal but also contributes to acoustic performance by minimizing resonance. Their versatility allows for easy integration into various audio systems, making them suitable for listening at home or setup in a dedicated home theater environment.

In conclusion, the B&K 125.7 S2 and B&K 125.5 S2 are exemplary audio solutions that reflect Bowers & Wilkins' commitment to quality and innovation. With their respective designs and advanced technologies, they provide audio enthusiasts with the clarity, depth, and precision needed for an exceptional listening experience.
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