9.If a video signal is being used to trigger the MA250 on and off, connect good quality short as possible video wire with a RCA jack to the MA250 “Video Input”. Make sure the music sense button is OUT.

10.If the music sense or video input is being used to turn the

MA205 on and off, set the “Music Sense” button to OUT. Adjust the Sens (sensitivity) so the MA250 turns on when quieter sound passages are playing. Adjust the “Delay” so the MA250 turns itself off 25-120 seconds after the sound has stopped.

11.Individually adjust the channel gains as required. Ideally, the gains are fully on (fully clockwise).

12.If the 12 volt trigger is being connected, use a 12 VDC source (about 35mA) with a 3.5mm mono jack. Knoll PS1202 with a new 3.5mm jack works well. 5 VDC triggers will not work.

Caution: Never listen to sound that is distorted. If distorted sound is heard, turn the volume down immediately or speaker and/or amplifier damage could occur that is not covered by the warranty. If this problem persists, contact your dealer.

MA250 REAR PANEL

 

 

Connect the “AMP INPUTS”

 

 

 

 

 

Caution: DO NOT CONNECT BRIDGED

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

speaker level inputs to the

AMPLIFERS or amps that do not have

 

 

 

 

 

Connect these

common grounds to the “AMP INPUTS”

 

 

 

 

 

whole house audio system

Connect a composite

 

 

 

 

unbuffered stereo

as you may damage the other amplifier.

 

 

 

 

or other amplifier outputs.

video output from a

 

 

 

 

line outputs to

 

 

 

 

 

 

 

The “AMP INPUTS” pass

 

 

 

VCR, plasma TV, etc.

 

 

 

 

other amplifier

 

 

 

 

 

 

 

directly to “TO SPEAKERS”

 

 

 

to the “Video Input” if

 

 

 

 

inputs as needed.

Connect the “TO SPEAKERS”

 

 

 

 

when the MA250 isn’t turned

the MA250 is to be

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

on.

 

 

 

 

 

 

 

 

 

 

 

to the 4-8 ohm speakers.

trigerred on when a

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

video signal is present.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Make sure the music

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

switched to the OUT

 

 

MA250

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TRIGGER

 

sense button is

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

12VDC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

position.

 

 

Stereo Amplifier

 

 

 

 

Input

Output

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INPUT

 

 

 

 

 

 

L

 

 

 

 

 

 

AMP

 

 

TO

 

 

 

 

Connect this 3.5mm

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

For video triggering

 

Knoll Systems

 

 

 

 

 

 

INPUTS

 

SPEAKERS

 

 

 

 

trigger jack if the

 

Point Roberts WA USA

 

 

 

 

 

 

 

L

R

 

L

 

R

 

 

 

 

MA250 is to be

 

 

 

 

 

 

 

 

 

 

without music sensing

 

Richmond, BC Canada

R

 

+

- - +

 

+

- - +

 

 

 

 

triggered on when a

turn the “Sens” pot

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

12 VDC signal is

fully counterclockwise.

Video

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

present. Polarity

 

Input

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sens Delay L Gain R

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

can be reversed.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Music

 

sense

 

 

 

 

 

 

 

 

 

 

 

 

 

It needs about

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CAUTION

 

 

 

 

Out = Active

 

 

Made in Canada

 

 

35 mA.

 

 

 

 

 

RISK OF ELECTRIC SHOCK

 

 

 

 

 

 

120 VAC / 1.5 A

 

 

 

 

 

DO NOT OPEN

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fabrique au Canada

POWER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

User adjustments and service: There are no user adjustments on the MA250. Your installer may make certain gain level adjustments on the rear panel.

Caution: The MA250 contains no user serviceable parts, so do not attempt to open or repair the

When using music sense only, adjust Sens so the MA250 turns on when the source music is at a medium low volume. Sens is not used for video on or trigger on. For video sensing without music sensing turn Sens fully counterclockwise.

After MA250 is on, Delay is adjusted to turn off MA250 after the source music ends. Ideal delay adjustment is about 20-40 seconds. Delay is used with video on and music sense only.

Adjust the gain when the system is on. Best signal to noise ratio is when MA250 gains are on full (clockwise).

The music sense (auto turn on when music is present) button should be OUT (active) when the MA250 power is to be triggered either from music sense or the composite video signal.

The music sense button should be IN when the amp is turned off and on from the front panel switch or the 12 VDC trigger.

MA250. Refer servicing to a qualified technician only or contact the factory for information.

Ideal speaker impedance is 4-8 ohms.

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Knoll specifications MA250 Rear Panel
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MA250 specifications

The Knoll MA250 is a notable addition to the world of office seating, combining style, comfort, and functionality in an elegant design. This chair is particularly designed for those who spend long hours working at a desk, catering to the needs of professionals who require both support and aesthetic appeal in their workspace.

One of the standout features of the MA250 is its ergonomic design. The chair offers a contoured backrest that provides essential lumbar support, promoting healthy posture during long periods of sitting. This feature is crucial for reducing fatigue and discomfort associated with prolonged desk work. Additionally, the seat height is adjustable, allowing users to tailor the chair to their specific preferences, ensuring optimal comfort.

The MA250 is built with high-quality materials, enhancing both its durability and visual appeal. The upholstery options available vary from premium fabrics to leather, allowing users to choose a finish that best fits their office decor. This versatility means that the MA250 can seamlessly integrate into various office environments, whether modern or traditional.

Another significant feature of the MA250 is its advanced mechanisms. The chair is equipped with a synchro-tilt mechanism that allows the backrest and seat to move in harmony. This feature supports users in a variety of seated positions, enabling comfortable transitions between tasks and promoting movement throughout the day. This adaptability makes the MA250 suitable for collaborative spaces where dynamic work habits are common.

In terms of sustainability, Knoll emphasizes eco-friendly practices in the production of the MA250. The materials utilized are sourced responsibly, and the design prioritizes longevity, aiming to reduce waste over time. The chair can be easily disassembled for recycling, reflecting a commitment to environmental stewardship.

With its combination of elegance, ergonomic design, and sustainable practices, the Knoll MA250 stands out as a premier choice for modern workspaces. Its thoughtful features cater to the demands of today’s professionals, ensuring that comfort and design go hand in hand. Whether in a private office, conference room, or shared workspace, the MA250 provides the balance needed for productivity and well-being in the workplace.
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