Sherbourn Pa 2-50 User manual

Owner’s Manual

PA 2-50

TWOOCHANNEL FLEX AMPLIFIER

Important Safety Precautions and Explanation of Symbols

The exclamation point within an equilateral triangle is intended to alert the user to the presence of

important installation, operation, and service instructions in this manual.

The lightning ash with arrowhead symbol within an equilateral triangle is intended to alert the user

to the presence of uninsulated dangerous voltages within the enclosure that may be of sufcient

magnitude to constitute a risk of electrical shock to the user.

Please read this Installation and Operation Manual thoroughly before attempting to install, congure,

or operate the Sherbourn PA 2-50. After successful installation and conguration of the PA 2-50, be

sure to retain this manual in a safe place for future reference.

Safety is a key component to a long lasting and trouble free installation. Please read and follow

all instructions and heed all warnings on the PA 2-50 and in this manual. The vast majority of the

subsequent safety precautions are common sense. If you are not comfortable with the installation

of audio/video entertainment equipment, you should seek the services of a qualied installation

professional or call us for help.

WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT USE THE

PA 2-50 NEAR WATER OR IN WET LOCATIONS, DO NOT EXPOSE IT TO RAIN OR MOISTURE,

DO NOT EXPOSE IT TO DRIPPING OR SPLASHING FROM OTHER SOURCES, AND ENSURE

THAT NO OBJECTS FILLED WITH LIQUIDS (SUCH AS VASES) ARE PLACED ON IT. DOING SO

MAY RESULT IN DAMAGE TO THE PA 2-50 AND THE RISK OF ELECTRIC SHOCK, WHICH MAY

RESULT IN BODILY INJURY OR DEATH.

WARNING: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE THE COVER

FROM THE PA 2-50. THERE ARE NO USER-SERVICEABLE PARTS INSIDE THE PA 2-50. REFER

ALL SERVICE TO QUALIFIED SERVICE PERSONNEL.

Do not install the PA 2-50 near or above any heat sources such as radiators, heating vents, or other

apparatus that produces heat. Do not block any ventilation openings or heat sinks. Avoid installing

the PA 2-50 directly above other heat-producing equipment unless sufcient ventilation or forced-air

cooling is provided.

Do not install the PA 2-50 in locations without proper ventilation. The PA 2-50 should not be operated

on a bed, sofa, rug, or similar surface that may block vents. The PA 2-50 should not be installed in an

enclosed location such as a bookcase, cabinet, or closed equipment rack unless sufcient forced-air

ventilation is provided.

Always install your PA 2-50 according to the manufacturer’s instructions and only use attachments or

accessories specied by the manufacturer.

Do not install the PA 2-50 on any stand, shelf, or other piece of furniture that is unable to support its

weight. If a cart is used to move the PA 2-50, use caution to avoid injury from tip-over.

Connect the PA 2-50 only to power sources of the correct voltage (as shown in this manual and on

the PA 2-50). Ensure that the Input Voltage selector switch on the rear of the PA 2-50 is set to the

appropriate voltage.

Protect power supply cables from being pinched, walked on, or otherwise damaged. Be especially

careful where the power cable enters the power outlet and the PA 2-50 unit.

Only connect the PA 2-50 to an electrical outlet or extension cord of appropriate type and rating.

DO NOT defeat the safety purpose of a grounding or polarized plug by removing ground pins or using

unsafe adapters. A polarized plug has two blades - one wider than the other. A grounding plug has a

third ground prong in addition to the two main conductors. The wide blade or third groundling prong is

provided for your safety. If the provided plug does not t your outlet, consult an electrician to replace

your obsolete outlet. If you replace the PA 2-50 power cord, only use one of similar type and equal or

greater current rating.

The power cable for the PA 2-50 should be unplugged from the outlet during severe electrical storms,

or when unused for a long period of time.

Only replace the fuse in the PA 2-50 with a fuse(s) of proper value and voltage rating.

The PA 2-50 should only be cleaned as directed in the Installation and Operation Manual. Avoid

spraying liquids directly onto the PA 2-50 and NEVER spray liquids into the vents. Care should be

taken so that small objects do not fall into the inside of the PA 2-50.

You should seek service for your PA 2-50 by qualied service personnel if any of the following occur:

1. The power-supply cord or the plug has been damaged.

2. Objects or liquid have fallen or spilled into the vents.

3. The PA 2-50 has been exposed to rain.

4. The PA 2-50 exhibits a marked change in performance.

5. The PA 2-50 has been dropped, or its enclosure or chassis is damaged.

NOTE: TO COMPLETELY DISCONNECT THE PA 2-50 FROM THE AC POWER MAINS,

DISCONNECT THE AC POWER CORD FROM THE AC RECEPTACLE.

NOTE: THE PA 2-50’s AC POWER CORD MUST REMAIN READILY ACCESSIBLE AT ALL TIMES.

CAUTION

CAUTION: TO REDUCE THE RISK

OF ELECTRICAL SHOCK, DO

NOT REMOVE COVER. NO USER

SERVICEABLE PARTS INSIDE.

REFER SERVICING TO QUALIFIED

SERVICE PERSONNEL.

Page 1

Contents

Important Safety Precautions and Explanation of Symbols

Introduction.................................................................................................2

The PA 2-50 Two-Channel Flex Amplier ...................................................2

About This Manual......................................................................................2

Mechanical and Environmental ..................................................................3

Remote Control ..........................................................................................4

Front Panel.................................................................................................5

Rear Panel..................................................................................................6

Inputs and Outputs .....................................................................................8

Installation Tips...........................................................................................9

Conguration ............................................................................................11

Remote Control Codes and Signal Specications....................................12

Performance Specications......................................................................14

Features ...................................................................................................15

Operation..................................................................................................16

Periodic Maintenance...............................................................................18

Troubleshooting........................................................................................19

Sherbourn Technologies, LLC Five-Year Limited Warranty......................20

Notes ........................................................................................................21

PA 2-50

Two-Channel Flex Amplier

Page 2

Introduction

Thank you for choosing the Sherbourn PA 2-50 Two-Channel Flex Amplier.

The Sherbourn PA 2-50 combines two great sounding audio channels, a precision digitally controlled

analog volume control, automatic input selection, exible remote control and triggering options, and

user-selectable AC supply voltage - all in one compact package.

Design features like proven class A/B technology, Sherbourn’s intelligent protection system, and true

commercial grade construction quality and reliability make the Sherbourn PA 2-50 an obvious choice

when you need a small, exible, great sounding two-channel amp.

About This Manual

This manual will provide you with all the information you need to install and congure the Sherbourn

PA 2-50 Two-Channel Flex Amplier to achieve its optimum potential. The manual also includes a

brief summary of the features offered by the PA 2-50 and a short description of how the controls

work and how to perform common operations.

You may wish to record serial numbers or other purchase information on the Notes page at the back

of this manual.

The PA 2-50 Two-Channel Flex Amplier

The Sherbourn PA 2-50 is a medium-powered, audiophile quality, class A/B power amplier with

a wide variety of input and control options. The PA 2-50 offers two stereo inputs, each of which

can be manually selected or congured to operate automatically, and utilizes a digitally controlled

analog level control, which provides very precise control of gain, very tight channel tracking, perfect

repeatability, and virtually no distortion.

The PA 2-50 offers the usual trigger input, as well as both IR and bi-directional RS-232 serial remote

control. Speaker connections (two sets) are industry standard Phoenix-type removable terminal

blocks; power is via a convenient removable IEC power cord, and is user selectable between 115

VAC and 230 VAC. Direct front panel control is provided for Input selection (with LEDs to indicate

the selected input), Power (an LED indicates status), and Volume control (a row of 8 blue LEDs

displays the volume setting).

Page 3

Mechanical and Environmental

8.5”

14.5”

14”

2.625”

TOP

FRONT

SIDE

3.125”

SHERBOURN

PA 2-50

19”

15”

8.625”

19”

17”

15”

2.375”

3.5”

2.375”

3.5”

UFP x1 (single rack mount kit)

UFP x2 (dual rack mount kit)

Page 4

Dimensions: 8.5” wide x 3.125” high x 14.5” deep (includes feet, binding posts, no rack kit).

Weight: 11.2 lbs / 5.1 kg (unboxed); 14.4 lbs / 6.6 kg (boxed).

Rack mountable: Yes, single or paired, with optional rack mount kits.

Power requirements:

115 VAC or 230 VAC +/- 10% @ 50 / 60 Hz (selectable by rear-panel switch).

Ventilation and cooling:

To avoid overheating, be sure to provide adequate clearance and ventilation.

OFF 1 ON

2 MUTE 3

415

-- VOLUME --

AUTO 29

6INPUT 7

Remote Control

Note: Only certain buttons on the remote control are used.

(On, Off, Mute, Input 1, Input 2, Input Auto, Volume Up, and Volume Down.)

Page 5

Front Panel

DN----------VOLUME ----------UP

STANDBY 1------------AUTO ------------2

1 5432 6

1. Standby Button

Switches (toggles) the unit between Standby and On.

2. Standby LED

Illuminates red for Standby; blue for On, ashing red for a Fault condition.

3. Infrared Detector Window

Used by the infrared remote control.

4. Input Selector Pushbuttons and Input LEDs

Pressing 1 or 2 manually selects that input; pressing Auto instructs the PA 2-50 to use whichever

input has active audio signal on it. (If both inputs are active, Input 1 has priority.) When each input /

mode is selected, the corresponding LED will illuminate.

5. Volume Up and Volume Down Pushbuttons

Press and hold either button to increase or decrease volume gradually.

6. Volume LEDs (8)

These LEDs indicate the approximate volume setting.

Note: The Volume on the PA 2-50 can be set in very small increments; the LEDs only show an

approximation of the current setting.

Page 6

Rear Panel

1, 2. Inputs (one stereo pair for each input; unbalanced)

Connect your line level inputs to these.

3. Outputs (one stereo pair; unbalanced)

Stereo passthrough output carries the selected input signal for chaining other devices.

4. Speaker Outputs (two each for left and right channel)

Phoenix-type connectors for connecting up to two pairs of speakers.

5. Power Switch

Switches the AC mains power to the PA 2-50 On and Off. When this switch is Off, the PA 2-50 will

not respond to trigger signals or manual controls.

6. Input Voltage Selector Switch

Always ensure that this switch is set for the proper line voltage for your area and installation.

7. RS-232 Serial Remote Control Interface

Accepts RS-232 control codes from a wired serial remote control.

Refer to the Remote Control Codes and Signal Specications section for details.

8. Trigger Input

The Trigger Input is used to allow other trigger-enabled equipment to switch the PA 2-50 between

On and Standby.

LEFT RIGHT LEFT RIGHT

RS-232 CONTROL

INPUT 1 INPUT 2 OUTPUT SPEAKER OUTPUTS

+ - + - + - + -

TRIGGER

IR IN

OFF

AUTO

AC INPUT

ON OFF

POWER

115

1 5432 6

7119 108

Page 7

9. IR Input.

Connect an external IR sensor to this input if the PA 2-50 is mounted such that IR remote control

signals cannot reach the front panel directly.

10. Power Mode Switch.

Selects between regular, triggered, and auto-on power modes.

Refer to the Installation Tips and Conguration sections for details.

11. Standard IEC Power Inlet.

The PA 2-50 requires a standard IEC C7/C8 (2.5A two wire) power cable.

Page 8

Inputs and Outputs

Analog inputs:

2 inputs; each one stereo pair of unbalanced (RCA) inputs.

Analog (line level) outputs:

1 output; one stereo pair of unbalanced (RCA) outputs .

Input sensitivity (for full output into 8 ohms):

600 mV

Speaker outputs:

2 pairs of two-terminal Phoenix-type connectors

(2 each; Left Speaker and Right Speaker).

Minimum recommended load impedance:

4 ohms (one 4 ohm load or two paralleled 8 ohm loads per channel)

(2 speaker outputs for each channel are paralleled; minimum total load impedance per channel is 4 ohms).

Trigger and control:

Trigger Input (mono 1/8”).

IR input (optical); window on front panel next to Standby switch.

IR Input (electrical; mono 1/8”); on rear panel next to Trigger Input.

RS-232 serial input/output; on rear panel (9 pin d-connector; female).

Front panel controls and indicators:

Standby; (large push button); toggles Standby mode.

Standby LED (1); red indicates Standby mode; blue indicates normal operation;

ashing red indicates a fault.

Input; pushbuttons; (1, 2, auto); select input / mode.

Input; LEDs (3); indicate active input / mode.

Volume Up, Volume Dn; pushbuttons.

Volume LEDs (8); indicate approximate volume setting.

Rear panel controls and indicators:

Power (rocker switch); switches mains power.

Input Voltage (protected slide switch); selects 115 or 230 VAC line voltage.

Power Mode toggle switch (On / Off / Triggered).

Remote control:

The Sherbourn PA 2-50 includes a compact infrared (IR) remote control.

May also be controlled by standard (user-supplied) multi-remote.

Remote control via RS-232 serial connected controller (bi-directional).

AC power input:

IEC C7/C8 (2.5A two wire) type inlet and power cord.

Page 9

Installation Tips

Input Switching

The Sherbourn PA 2-50 has two separate stereo inputs. Explicitly choosing either Input 1 or

Input 2 (by either the front panel buttons, the IR remote, or the RS-232 remote) selects that input

as the signal source; choosing Auto as the signal source instructs the PA 2-50 to use whichever

input signal is active; if Auto is selected, Input 1 has priority over Input 2 if both inputs are receiving

signal. If only a single input is to be used, Input 1 should always be chosen to assure optimum

performance.

Auto Power Mode

When the rear panel Power switch is set to On, and Power Mode is set to Auto, the PA 2-50 will

switch On when signal is detected at either input (regardless of which input is selected as the signal

source).

Volume and Input Setting Persistence

When the PA 2-50 is powered On from a full shutdown, or returned to operating mode from Standby,

the Volume level and Input selection will return to the settings in effect when the PA 2-50 was shut

down.

Volume Lockout

The Sherbourn PA 2-50 has a special user Volume control lockout feature. This feature is engaged

by pressing the front panel Input 1 button and holding it for approximately 3 seconds. THIS

LOCKOUT MODE WILL REMAIN IN EFFECT EVEN IF THE PA 2-50 IS SET INTO STANDBY

MODE OR POWERED OFF AND ON AGAIN. The lockout mode is disengaged by again pressing

the front panel Input 1 button and holding it for approximately 3 seconds.

When the lockout mode is engaged, the front panel Volume controls and the IR Volume control

are disabled; the RS-232 Volume control functions will still operate normally. (This is not a Mute

function; the Volume remains set as it was when the lockout was initiated.) When the Input 1 button

is pressed to engage the lockout mode, the Input selection will also switch to Input 1. Since the Input

selection controls are not locked out, Input 2 or Auto may be re-selected afterwards.

Ventilation and cooling

Even though the PA 2-50 is quite efcient, it still produces some heat; to avoid overheating, be sure

to provide adequate clearance and ventilation, and do not block the vents. Overheating adversely

affects performance and shortens component life. We suggest locating components that produce

the most heat towards the top of your rack if practical, and leaving at least 1U (1.75”) of rack space

between components. Space between components can be left open for ventilation, lled with a

spacer, or used to house a forced-air cooling solution.

Sherbourn’s C-12 Flex Rack™ Cooling System uses whisper quiet high capacity variable speed

fans to provide over 100 CFM of forced air cooling for rack installations. The C-12 offers a variety of

air-ow options (including external ducting), includes professional features like triggered operation

and thermostatic control, and takes up only 2U of rack space.

Page 10

IR Remote Control Input

If the PA 2-50 is installed in a location where the front panel IR remote window is blocked, an

external IR receiver may be connected to the IR In connector on the rear panel.

Rack Mounting Options

The Sherbourn PA 2-50 may be rack mounted using the Sherbourn UFPx1 rack mount kit. Two

PA 2-50 units may be mounted side by side in a 19” rack using the Sherbourn UFPx2 rack mount kit.

Page 11

Conguration

Operating Voltage - Verify that the Sherbourn PA 2-50 is congured for the correct operating

voltage for your area. (Voltage is set via the AC Input switch on the rear panel of the PA 2-50).

Power Mode - The way in which the PA 2-50 responds to the Trigger Input, audio signals, and

the front panel Standby switch is determined by the setting of the Power Mode switch (the small

bat switch on the rear panel below the speaker outputs, to the right of the Trigger and IR Inputs).

When the rear panel Power rocker switch is set to Off, the PA 2-50 is powered completely off and

will not respond to any other control, switch setting, or input. In order for the PA 2-50 to operate as

described below, the rear panel Power rocker switch must be set to On.

• When the Power Mode switch is set to On, the PA 2-50 is controlled by the front panel Standby

switch, which toggles between Standby and operating (On) modes each time it is pressed.

• When the Power Mode switch is set to Auto, the PA 2-50 is controlled by audio input; the PA

2-50 switches On when there is audio signal present at any of the inputs (this will occur even

when audio arrives at an input which is not assigned as a source); the PA 2-50 will return to

Standby mode about fteen minutes after audio input signal is no longer present.

• When the Power Mode is set to Off, the PA 2-50 will switch On when a trigger signal is received,

and will return to Standby mode when the trigger signal is no longer present.

Remote Control - The PA 2-50 responds to certain remote control commands (including the Power

On command) when in Standby mode. The rear panel Power rocker switch is a manual, mechanical

switch; when it is set to Off, the PA 2-50 is powered completely off and will not respond to any

remote control commands. The remote control Power Off commands (and the Standby button)

return the PA 2-50 to Standby, but do not remove all AC mains power (the remote control receivers

remain powered on).

Page 12

Remote Control Codes and Signal Specications

RS-232-Serial Codes

The Sherbourn PA 2-50 responds to serial codes in standard text format.

The following list of codes must be sent precisely as shown;

everything after the equals sign (=) is part of the code, INCLUDING THE SINGLE QUOTES;

the single quotes (apostrophes) MUST be included or the code will not be accepted

• Power On = ’@112’

• Power Off = ’@113’

• Input 1 = ’@15A’

• Input 2 = ’@15B’

• Input Auto = ’@15Z’

• Mute On = ’@11Q’

• Mute Off = ’@11R’

• Mute Toggle = ’@11U’

• Volume Up = ’@11S’

• Volume Dn = ’@11T’

• Volume Direct = ’@11P’xxx

(xxx represent three decimal digits from 000 to 080 -

000 is full volume; 080 is minimum volume)

Recommended serial port settings are 9600,N,8,1, NO handshake

Required cable is a “standard one-to-one male-to-female 9-pin D-sub serial cable”;

the PA 2-50 requires pin 2 to pin 2, pin 3 to pin 3, and pin 5 to pin 5

(you may use a fully wired one-to-one cable; do NOT use a “null modem” cable)

IR Remote Control Codes

The Sherbourn PA 2-50 responds to “16-bit custom NEC style IR codes”

• Power On = 01F601

• Power Off = 01F604

• Input 1 = 01F606

• Input 2 = 01F60A

• Input Auto = 01F609

• Mute Toggle = 01F605

• Volume Up = 01F60C

• Volume Dn = 01F60E

To generate the “full NEC IR codes”, enter these codes into IR Code Doctor or a similar code

converter, choose to Create an NEC Code; the left 4 hex digits are converted into decimal

(01F6 hex = 502 decimal) and entered into the System eld; the right two hex digits are converted

into decimal and entered into the Command eld. This will yield what some vendors refer to as the

“full NEC IR code”; converting to RAW will yield the “Pronto” style code.

These codes are provided for you on the next page (and may be cut and pasted from the PDF

version of this manual). Simply cut and paste ONLY the block of numbers after the equals sign into

your code editor.

45 123

9 678

PA 2-50 rear panel

D-sub 9-pin female