Sherbourn Technologies LDS-2.150 Owners manual

5. Adhere to all warnings and follow all operating
instructions.

6. Warning: To reduce the risk of fire or electri­cal shock, do not expose this equipment to rain
or moisture.
There are no user serviceable parts inside. Refer
servicing to qualified personnel.

7. Caution: To prevent electrical shock do not use
this (polarized) plug with an extension cord, re­ceptacle or other outlet unless the blades can be
fully inserted to prevent blade exposure.

Model LDS2/150
Owner’s Manual

Thank you so much for your decision to purchase
one of our superb Sherbourn amplifiers. We take
enormous pride in the design and build quality of
all of our products and we are confident that our
product will provide you with many years of enjoy­able and trouble-free service. Should you have
any need to call upon our services please feel free
to contact us at the address shown at the end of
this booklet; or, of course, you can contact the deal­ership from which you purchased the product.

Full details of the warranty coverage provided by
Sherbourn Technologies can be found at the end of
this booklet.

Safety Instructions

1. Important Safety Instructions! Please read
all the safety and operating instructions shown
in this manual before operating this equipment.

8. For added protection for this product during a
lightening storm or when it is left unattended and
unused for long periods of time, it is recommended
that you unplug the unit from the wall outlet. This
will prevent damage to the product due to lighten­ing or power line surges.

9. Do not use attachments not recommended in this
owner’s manual as they may cause hazards.

10. Locate the equipment for proper ventilation.
For example, the product should never be allowed
to operate while positioned on a bed, rug, sofa or
any such surface where proper ventilation is not
possible. Nor should the unit be placed in a built-in
installation such as a cabinet or armoire, etc. in such
a way as to impede the air flow. Always ensure
adequate ventilation openings - please see later com­ments regarding such an installation.

11. Locate the product away from heat sources such
as stoves, heat registers, radiators or other appli­ances including other amplifiers that produce heat.

12. Mount the equipment in a wall or cabinet only
as described in this owner’s manual.

2. The lightening flash within an equilateral triangle
shown above is intended to alert you to the pres­ence of uninsulated ‘dangerous voltage’ within the
product’s enclosure that may be of sufficient mag­nitude to constitute an electric shock.

3. The exclamation point within an equilateral tri­angle shown above is intended to alert you to the
presence of important operating and maintenance
(servicing) instructions in the literature accompa­nying this appliance.

4. Please retain this manual in a safe place for fu­ture reference about safety and operating matters.

13. Do not use the equipment near water; for ex­ample near a bathtub, washbowl, kitchen sink, a
wet basement, swimming pool, etc. This product
is meant for indoor use only.

14. Do not place the product on an unstable cart,
stand tripod, bracket or table. The equipment is
heavy and should it fall, it could cause serious in­jury to a person and/or serious damage to the equip­ment.

Caution For Installation

1. Your Sherbourn amplifier can be placed on any
table or shelf. It can also be custom installed in a
rack, and/or in a piece of cabinetry or furniture of
your choice. It is however, important that if the

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amplifier is going to be housed in an enclosed envi­ronment, that you allow for adequate ventilation.
Despite the adequately sized heatsinks built into the
amplifier, it is still important that good ventilation
be provided. Do not install the amplifier directly
above another heat generating component such as
another amplifier without adequate ventilation.

2. If your amplifier is going to be placed in an en­closed space such as an armoire, it is essential that
adequate ventilation be provided.

3. The dealership from which you purchased the
product is an expert on custom installation proce­dures and can provide invaluable advice to help you
make an aesthetically pleasing and trouble free in­stallation.

Caution For Connections

1. Connect this equipment only to the type of AC
power source as marked on the unit. Always route
AC power cords so they are not likely to be walked
on, or tripped over, or where they may be pinched
by items placed on or against them. Always pay
particular attention to cords at plugs and/or conve­nience receptacles, and at the point where they exit
from the product.

not permit objects of any kind to be pushed and/or
fall into the product through the enclosure open­ings.

General Description

The 2/150 is an intuitive product that has been de­signed primarily to facilitate seamless switching
between a television and an installed music system.
Since it is assumed that an audio system is already
in place, the 2/150 has designated that this will be
the primary system and so it is referred to as “A”
and the interrupter part of the 2/150 is referred to
as ‘B’.

The 2/150 outputs a total of 2 x 50 watts into an 8
ohm load and 2 x 75 watts into a 4 ohm load. The
amplifier will drive two pairs of 8 ohm speakers or
one pair of 4 ohm speakers. An embedded MPU
(Micro Processing Unit) ensures that the amplifier
cannot be ’overdriven’, and the LDS (Load Detec­tion System) ensures that all speaker connections
must be good before the amplifier is connected to
the speakers.

The 2/150 has an automatic internal sub-sonic fil­ter of -18dB per octave which rolls off very low
frequency content (below 20 Hz) to avoid low fre­quency saturation of a transformer volume control.

2. Do not defeat the inherent design features of the
polarized plug. Non-polarized line cord adapters
will defeat the safety provided by the polarized AC
plug. If the plug should fail to fit, contact your
electrician to replace your obsolete outlet. Do not
defeat the safety purpose of the grounding-type
plug. If you use this product in a country which
only has two slotted receptacles in the house, you
must use a three-pin adapter plug to earth ground
which is the “E” (earth pin) of the power cord con­nected to this product.

3. Do not overload wall outlets, extension or inte­gral convenience receptacles, as this could result in
a risk of fire or shock.

Operating Voltage

The LDS2/150 amplifier is factory-set for 110V,
120V or 230V AC operation at either 50 or 60 Hz,
according to the country for which the unit was
manufactured (230V in European Union countries,
in compliance with CE regulations). The operat­ing voltage cannot be changed by the user and any
attempt to do so will void the warranty.

Care of the Product

Clean the product by dusting with a dry cloth. Do
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The unit can be set for a bridged/mono application
in which case the output will be 130 watts.

The 2/150 has a great many features all of which
are described in this manual.

Front Panel Description

The front panel has a number of important controls
with which you should familiarize yourself.

The blue LED will glow brightly when the unit is
active and will dim considerably whenever the unit
is in its ‘sleep’ mode.

B Off Delay

Controls the priority ‘zone’ and enables you to set
the delay time for the ‘B’ zone from 0.3 minutes to
a maximum of 5 minutes. You need to set the front
input selector to either ‘B’ or ‘Auto’ in order to
use the ‘B Off Delay’.

B On Level

Control allows you to set the sensitivity of the auto­turn on circuit to be triggered by the ‘B’ input. The
range of this adjustment is from -86 dB below rated
output (indicated as ‘LO’ on the front panel) to ­72 dB below rated output (indicated as ‘HI’ on the
front panel).

Input A/B/Auto

Switch allows you to select either ‘A’ input only
(always play signal from ‘A’ input), or ‘B’ input
only (always play signal from ‘B’ input) or Auto
which allows that whenever there is an input signal
present at ‘B’ input it will override ‘A’.

Line Output (Buffered)

For use whenever a ‘daisy-chain’ installation and
multiple 2/150’s are used. ‘Line Output’ outputs
the signal from ‘A’ input if the 2/150 is playing the
‘A’ input, or outputs the signal from ‘B’ input when
the 2/150 is playing ‘B’ input.

Volume

Control allows you set a preferred level on both
‘A’ and ‘B’.

Rear Panel Description

The following description identifies each of the main
controls/connection options and follows the rear
panel from left to right.

Input A

Offers both speaker level and line level inputs for
the non-priority zone. These inputs are paralleled
inputs to the 2/150 and only one input can be used
at a time. A ‘balanced’ input buffer is incorporated
in the speaker level input circuit; it will accept an
output signal from either a ‘grounded’ or ‘floating’
music source.

Input B

This is the ‘priority’ zone and it is to these inputs
that you would normally connect the product over
which you seek to maintain control from the exter­nal amplifier. Similarly to input ‘A’, both ‘B’ in­puts are paralleled inputs to the 2/150 amplifier,
and again, only one input can be used at a time. A
‘balanced’ input buffer is also employed in the
speaker level input circuit; it will accept an output
signal from either a ‘grounded’ or a ‘floating’ mu­sic source.

Input B Triggers

These controls give you multiple options for your
priority system and are used in connection with
INPUT B inputs.

Video In Jack

Works only with the ’B’ input. To use this trigger
input, first set the trigger input selector to 12V/
Video position. The 2/150 will turn on exclusively
when it sees a video signal present at this video
input jack.

Music

Works only with the ‘B’ inputs. With the 2/150’s
‘B’ trigger switch in the ‘music’ position, it will
automatically function once it receives a music sig­nal and will move into its standby mode whenever
the signal is absent for a period exceeding the delay
time set by the ‘B Off Delay’ control on the front
panel.

12V / Video

Works only with the ‘B’ inputs. With the 2/150’s
‘B’ trigger switch in the ‘12V/Video’ position, the
2/150 can be turned on from a ‘sleep’ state when­ever a 6V to 15V input signal appears at the 12V
input connector or a video signal at the ‘Video In­put’ jack . 12V trigger and video trigger inputs are
connected in parallel, only one of the inputs should

Fig. 1. Front panel view

Fig. 2. Rear panel view

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be used at a time.

12 Volt Connector

For 12V trigger input and output use the upper two
circuits marked ‘+IN-’ for 12V trigger input (to
turn on the 2/150 amplifier) and use the lower two
circuits marked ‘-Out+’ for trigger output. The in­put accepts only a continuous DC trigger signal
from 6V minimum to 15V maximum for turning on
the 2/150 amplifier.

The trigger output is capable of delivering a con­tinuous 12V, 30 mA of DC current to drive the
down-stream products (or multiple units of 2/150
amplifiers) that may be associated with the 2/150
amplifier.

Protection Features

Your 2/150 includes some important circuits that
are designed to protect the amplifier.

LDS (Load Detection System)

The LDS feature is a patent pending circuit that
prevents ‘bad’ speaker connections to be made that
could cause the amplifier to ‘short’.

MPU (Micro Processor Unit)

The MPU circuitry measures the impedance of the
speaker load that is intended to be connected. The
MPU only permits impedances above 3.5 ohms to
be connected.

Mode Switch

This control allows for a selection of ‘Stereo’
‘Mono’ or ‘Mono/Bridged’. In the latter mode, the
maximum output power is 150 watts. Please note
that ‘R-Channel’ input is accepted under the bridged
operation. Bridging is ONLY recommended when
8 Ohm speakers (or greater impedance) are used.

Input A Trigger

This control gives you the flexibility to have an in­put trigger for the ‘A’ zone. Like the priority ‘B’
zone, the sensitivity of the signal can be adjusted
from a low of –86 dB to a maximum of –72 dB of
the input signal.

NOTE: when playing the ‘A’ input; if the music
is discontinued for longer than 10 minutes, the
2/150 will automatically enter its sleep mode to
cut down on energy consumption. The front blue
LED will then ‘dim’ to indicate that the ampli­fier is in ‘Sleep’ and will only return to its full
luminance when it again receives a music sig­nal.

LDS LED

This important control indicator is provided to in­dicate the correctness of your speaker connections
and to indicate that the intended speaker load is
not too great for the amplifier.

Speakers 1 and 2

These are the speaker-out terminals that are con­nected with the cables from the loudspeakers.

Power Switch

Normally once you have switched on the amplifier
the signal sensing mode or the 12 volt trigger switch
will ensure that the amplifier goes into a ‘sleep/
standby’ mode whenever it is not being directly
used.

How to use the LDS and MPU
Test Functions

1. In order for the 2/150 to correctly carry out its
designated LDS and MPU test functions, you must
make all of your speaker connections with the mas­ter power switch in the ‘off’ position.

2. Only when you are satisfied that you have made
all the connections correctly should you turn the
power switch to its ‘on’ position. Once the switch
is on the ‘on’ position the 2/150 will then proceed
with its diagnostic testing and the result will show
with the rear panel LED illuminating in either Green
or Orange.

3. If the LED illuminates in Green then everything
has been tested satisfactorily.

4. If the LED continues to flash in orange then
there is a problem with either a) the speaker con­nections or b) the load impedance of the speakers.

5. To determine if the problem is one of ‘connec­tion’ you should listen to see if the synchronized
test tone is absent from any of your speakers. If
you do not hear the tone from one of the speakers,
it is almost certainly that will be the one with the
bad connection. You should turn off the power and
carefully reconnect the speaker cables and then re­peat (2) above.

6. If the same synchronized test tone can be heard
from all the speakers, then almost certainly it is be­cause the impedance is too low. If you are trying to
use more than two pairs of speakers, it is suggested
that you remove one pair, turn off the amplifier and
then carry out another test by repeating step (2). If
this solves the problem, then it will indicate that
the load impedance with the two pairs of speakers
was too low. If the amplifier still does not work,

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then it is suggested that you consult the speaker manu­facturer to determine the exact impedance of the loud­speakers.

7. The LDS function refers to a ground potential

for measuring the speaker impedance. It does not
measure the speaker under the bridge mode opera­tion and care should therefore be exercised in con­necting the speaker wires when the 2/150 is being used
in its bridged mode.

Fig. 3. 2/150 Configured as an A-B Switcher.

For this configeration, set the front panel input selector to ‘auto’. When the Plazma TV is turned on, the
sound of TV will take over the speakers from the house music playing by the receiver or power amplifier. If
the Plazma TV has a line level output, use it instead of the speaker output (as shown). Use a set of audio cables to

connect the TV line outputs with the RCA jack line inputs under ‘Input B’ of the 2/150.

Fig. 4. 2/150 configured as a Stereo Amplifier.

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Fig. 5. 2/150 Configured in Bridged Mode.

Use only the right channel inputs for bridged connection. Connect the “+” polarity of the speaker to the
“R+” speaker output, and the “-” polarity of the speaker to the “L+” speaker output.

Fig. 6. Location of bottom cover keyway slots used to mount the amplifier vertically against a wall with screws.

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Fig. 7 Optional Rack Panel assembly

Note 1 - Remove two M4 flat head screws from front panel of amplifier and use them to fasten the amplifier to the
Rack Panel as shown above. The amplifier front panel is not removed.

Note 2 - Fasten the Alignment Bar (when two amplifiers are used) to the bottom cover of the amplifier using the two
screws already in place. This will hold the back of the amplifiers in alignment.

Note 3 - When only one amplifier is mounted to the Rack Panel, the second opening can be covered with a Cover
Plate that is not part of this kit.

Each Rack Mount Kit contains:

Item Qty Name To Mount
(1) 1 Rack Panel
(2) 1 Alignment Bar
(3) 4 10-32 x 1" truss head screws Rack Panel
(4) 4 #10 shoulder washers Rack Panel
(5) 2 existing amplifier screws Alignment Bar

Separately available from Sherbourn:

(6) 1 Cover Plate with mounting screws

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Three Year Limited Warranty

Subject to the terms and conditions stated be­low, Sherbourn Technologies, Inc. (Sherbourn)
warrants to the original owner that this model
LDS2/150 shall be free from defects in work­manship or materials for a term of three (3)
years from its date of purchase from an Autho­rized Sherbourn Dealer. Transfer of this prod­uct by its original owner (the ‘Owner’) will au­tomatically terminate this Warranty regardless
of when occurring.

In the event of any defect covered by this warranty,
Sherbourn shall provide all parts, materials, and la­bor necessary to restore the Product to its original
specifications, and shall return the Product to its
owner at Sherbourn’s expense. In the alternative,
Sherbourn may at its sole option either replace the
Product without charge, or if its replacement is not
commercially practicable or repair or replacement
cannot be accomplished within a reasonable time,
Sherbourn may refund the purchase price of the
Product, subject where appropriate to reasonable
depreciation for actual use in accordance with ap­plicable laws, in full satisfaction of its warranty ob­ligations.

Sherbourn’s sole obligation under this warranty
shall be to repair or replace the product, or at its
option refund the purchase price, as provided for
hereinabove. Sherbourn does not warrant
against, nor shall it be liable for, any of the fol­lowing: removal or installation charges, shipping
expenses to Sherbourn or its authorized service
facility, loss of use, property damage of any kind,
or other incidental or consequential damage or
losses of any kind.

Note: Some states do not allow exclusion or limi­tation of consequential damages, so the foregoing
exclusions may not apply to you.

one other than Sherbourn or an Authorized
Sherbourn Service Facility; and Sherbourn shall
have no liability or obligation of any kind with re­spect to any of the foregoing losses types of fail­ures.

To obtain service under this Warranty, the Owner
must first obtain from Sherbourn a Return Autho­rization Number, and must then, at the owner’s ex­pense (i) arrange for any necessary de-installation
of the Product, and (ii) deliver or ship the Product,
properly packaged and clearly identified with the
Return Authorization Number, prepaid, and insured,
to Sherbourn at the address shown below, or to an
Authorized Sherbourn Service Facility. In addi­tion, the Owner must provide evidence that the
Product is at the time of delivery within the scope
of this Warranty, by including the ORIGINAL dated
sales receipt with the Product when submitted for
repair. Safeguard your original sales receipt, as it
may be required to validate Warranty coverage

The owner is solely responsible for payment of all
expenses for removing the Product from its instal­lation, delivering it to Sherbourn or an Authorized
Sherbourn Service Facility, and reinstalling it fol­lowing repair, as well as for any repairs made to
Products which are subject to the exclusions noted
above.

In order to learn the name and address of the near­est Authorized Sherbourn Service Facility, obtain
a Return Authorization Number and shipping in­structions, or obtain answers to any other ques­tions you may have concerning this Warranty, you
may telephone Sherbourn between the hours of 9:00
am and 5:00 pm Eastern Standard Time, Monday
through Friday at [phone], or write to our
Service Department at Sherbourn Technologies,
Inc., 19-3A Sterling Road, North Billerica, MA

01862.

This warranty does not cover any of the following:
(a) cabinetry, trim, or other appearance items (ex­cept where they are defective at the time of origi­nal sale and the Product is delivered for repair within
the first thirty days (30) thereafter): (b) failures aris­ing from accident, catastrophe, misuse, neglect, or
failure to properly connect and operate the prod­uct in accordance with the accompanying instruc­tion: (c) failures arising from improper installation
of the Product or incompatibility of other compo­nents in the system of which the Product is a part:
(d) failures of any kind in products (i) which have
been purchased from other than Authorized
Sherbourn dealers, or (ii) which evidence any tam­pering, alteration, or attempted servicing by any-

8

This warranty gives you specific legal rights, and
you may also have other rights which vary from
state to state.

If this product has been purchased outside of the
United States of America, you should contact your
local dealer or distributor to determine the war­ranty coverage provided in your country.

Sherbourn Technologies, Inc.,19-3A Sterling Road,
North Billerica, MA 01862 Tel [phone]
Fax [phone] Web www.sherbourn.com