B&K 4420 User Manual

1.03 Mb

B & K Components Ltd.

P/N 12692

B&K Components, Ltd., 2100 Old Union Road, Buffalo, New York 14227














































































Safety Precautions


















































Page 2

Purpose and function


















































Page 3

Design and construction


















































Page 3



















































Page 3

Rear panel view


















































Page 4

Rear panel description


















































Page 4 - 5




Control muting


















































Page 5 - 6




Level controls


















































Page 6






















































Page 7






















































Page 7 - 8

System installation


















































Page 9

Making the connection


















































Page 9 - 10



















































Page 11

Care and cleaning


















































Page 11



















































Page 12



















































page 13






























Manual and Power cord

Page 1


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 be sufficient magnitude to constitute a risk of electric shock to you.

The exclamation point within an equilateral triangle is intended to alert the user of the presence of important operating and maintenance (servicing) instructions in the literature accompanying the unit.

Observance of polarity is essential. Double-checkconnections before turning the amplifier on. The amplifier can be damaged if polarities are incorrect.

Damage can occur to your speakers if the power rating* of each individual driver is exceeded by the amplifier. Ensure that all the drivers in your speaker system are capable of handling not only the power being delivered by the amplifier, but the energy that is likely to be generated during strong passages.

Turn amplifier ‘off’ when plugging in or unplugging input and speaker cables!!!

The Reference 4420 is equipped with raised feet so that continuous ventilation can be maintained. They help to maintain acoustic feedback into the amplifier at a minimum. They also provide a measure of protection against scratching any

surface the unit might be resting on.

Do not stack anything on top of the amplifier (preamplifier, processor, source...etc.).

Leave at least 2-3inches clearance from the top of the amplifier to the next shelf, component, etc., to ensure proper ventilation.

*If you are at all unsure of what the speaker ‘ratings’ are, contact your dealer.

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The Reference 4420 is a compact, very efficient, two channel power amplifier. It is designed to be used in all types of audio or audio/video systems.

The Reference 4420 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 include state-of-the-artsolid state devices, 1% metal film resistors, computer grade electrolytic power supply capacitors, and a high capacity toroidal transformer.

The Reference 4420 operates class A predriver and AB high current MOSFET power output stages. It is capable of reproducing the most demanding audio signals at rated power levels.

- Efficient high current transformer for improved dynamics.

- More accurate and three dimensional reproduction of source material.

- Improves low level detail for smoother, more musical sound.

- For efficient and linear power delivery.

- Provides short term protection from accidental shorting of output devices and protection from thermal overload.

- Improve connections for better sound and minimized signal loss and degradation.

- Low noise resistors for better sound and a greater degree of repeatability.

- Ability to reproduce demanding recordings.

- Large capacity computer grade electrolytic capacitors for extended low frequency control and improved dynamics.

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AC fuse holder


RCA inputs (unbalanced)


AC Input receptacle


Level controls **


Speaker outputs


Amplifier control muting input/output


Balanced inputs





























































































































































































































































































































































































































































































































































































































































































1. AC fuse holder - Holds the AC Line fuse. This fuse is an 12 Amp / 250 Volt

Slow Blow fuse. Replace with same type and value fuse only.

2. AC Input receptacle - For attaching the supplied AC power cord to the amplifier.

3. Speaker outputs - For connecting the speakers to the amplifier. Explained further on page 7.

Page 4

4. Balanced inputs - For connecting balanced signal patch cables (XLR).

Explained further on page 8.


RCA inputs -

For connecting signal patch cables (interconnects) from the



preamplifier to the amplifier to pass signal.


Level controls -











































































































































































adjusting the input level to the amplifier. Explained further



on page 6.

7. Amplifier control muting input/output -

To provide remote switching of mute on/off of the amplifier. Explained further below.

A control is provided on each Reference 4420 amplifier to allow remote switching of mute on/off. The preamplifier’s control output, such as is provided with B&K series preamplifiers, can be utilized to provide a control signal to the Reference 4420. If more than one amplifier is being controlled, the control signal can be extended to include each successive unit by simply running an RCA type audio cable from the CTRL OUT connector of the first amplifier to the CTRL IN connector of the next unit (commonly referred to as ‘daisy chaining’). An example of how to connect two amplifiers is illustrated in figure B.

If a source other than a B&K series preamplifier is used to control multiple amplifiers, only the control output voltage from the source is critical. It must be within the range, as indicated on the rear panel, 5-24volts DC is required. The amplifier will provide each successive amplifier with a control voltage of 12 volts DC for reliable operation. The amplifiers control output may be used as a source of 12 VDC @ 125 mA for other user applications as well.

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If the control function is desired, each unit in the system must remain connected at all times and the control must be enabled. To enable the control function, the CTRL

ENABLE button must be out for each controllable amplifier in the system. For more information on the amplifiers output status under various control conditions, refer to the table below.





















































































































































Button position











Output status



























































































































































































































































































































































































































































































































No Signal












































No Signal











































































































































No Signal
































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































The level controls are an option that can be added to the amplifier. If your amplifier has this option, the balanced inputs are not present.

There are two level controls on the back of the amplifier. One level control for each channel.

When using the level controls, first start with them turned all the way up (clockwise).

Then adjust them according to your system requirements to match the sound level coming from each speaker.

Page 6

Five way binding posts are provided. One pair for each channel. They are designed to accept a banana-typeplug or spade lug connector (shown below) and are color coded for easy identification. The red (+) post should always be connected to the speakers (+) jack. The black(-)post should always be connected to the speakers(-)jack.

Spade connector Banana jack

Here is a typical amplifier setup:

Unbalanced - RCA type connectors accept line input from the preamplifier’s unbalanced output connectors. There are two input connectors, one for each channel, that may be used to connect the amplifier to the preamplifier.

RCA cable connector -

Operation - For unbalanced operation, ensure the balanced switch between the balanced inputs on the rear of the amplifier is in the ‘off’ (out) position. If the amplifier does not have balanced inputs then it is always in unbalanced mode.

Page 7

Balanced - XLR type connectors accept line input from the preamplifier’s balanced output connectors. There are two input connectors, one for each channel, that may be used to connect the amplifier to the preamplifier.

Balanced cable connector -





















































































































































































Operation -






For balanced























operation, ensure the balanced switch between the balanced inputs on























the rear of the amplifier is in the ‘on’ (in) position.










































































































































































































































































































































































Here is a typical input setup:

Page 8