Wohler AMP-S8 Series User manual

Title and Contents ..............................................................
Important Safety Instructions and Introduction ...................................
Section 1: General Features and Specs ....................
Quick Start Guide .............................................................................
Description and Features ...................................................................
Applications and Specifications ..........................................................
Installation .........................................................................................
Section 2: Operation ...........................................................
Front Panel Features .........................................................................
Rear Panel Features ..........................................................................
Introduction to the User Interface ......................................................
User Interface Features .....................................................................
Presets Definitions .............................................................................
User Interface Function Guide ...........................................................
DM1, DM2, and DM3 Downmix Block Diagrams .............................
Section 3: Technical Information ................................
General Technical information ............................................................
..
Balance Control Characteristics .........................................................
AMP-S8 Series+ Interconnect Block Diagram ..................................
AMP-S8 Series+
(DA, SDA, HDA, and MDA Models)
Multi-Format Analog/Digital Audio Monitor
1U or 2U with HD-SDI, SD-SDI, AES, ANALOG Inputs,
HD-SDI, SD-SDI, AES, ANALOG Outputs, LCD Display,
Eight 53-Segment Level Meters, and Phase Indication
Document P/N 821640 Rev-B
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CONTENTS
1
© 2006 Wohler Technologies Inc. ALL rights reserved
User Manual

© 2006 Wohler Technologies Inc. ALL rights reserved
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AMP-S8 Series+ User Manual P/N 821640 Rev-B
The Tascam trademark is owned by Teac Inc.
Introduction
Congratulations on your selection of a Wohler Technologies AMP-S8 Series+ audio monitor unit. We are confident it represents the
best performance and value available, and we guarantee your satisfaction with it.
If you have questions or comments you may contact us at:
Wohler Technologies, Inc.
31055 Huntwood Avenue
Hayward, CA 94544
Phone: [phone] Fax: [phone] US Toll-Free: 1-888-596-4537
web: www.wohler.com e-mail: [e-mail]
1) Read these instructions.
2) Keep these instructions.
3) Heed all warnings.
4) Follow all instructions.
5) Do not use this apparatus near water.
6) Clean only with dry cloth.
7) Do not block any ventilation openings. Install in accordance with the manufacturer's instructions.
8) Do not install near any heat source such as radiators, heat registers, stoves, or other apparatus (including
amplifiers) that produce heat.
9) Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades
with one wider than the other. A grounding type plug has two blades and a third grounding prong. The
wide blade or the third prong are provided for your safety. If the provided plug does not fit into your outlet,
consult an electrician for replacement of the obsolete outlet.
10) Protect the power cord from being walked on or pinched, particularly at plugs convenience receptacles
and the point where they exit from the apparatus.
11) Only use attachments/accessories specified by the manufacturer.
12) Use only with the cart stand, tripod, bracket, or table specified by the manufacturer, or sold with the
apparatus. When a cart is used, use caution when moving the cart/apparatus combination to avoid injury
from tip-over.
13) Unplug this apparatus during lightning storms or when unused for long periods of time.
14) Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been
damaged in any way, such as when power-supply cord or plug is damaged, liquid has been spilled or
objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not
operate normally, or has been dropped.
15) Do not expose this apparatus to rain or moisture.
16) The apparatus shall be connected to a mains socket outlet with a protective earthing connection.
Important Safety Instructions
CAUTION!
In products featuring an audio amplifier and speakers, the surface at the side of the
unit, where the audio amplifier heat sink is internally attached, may get very hot after
extended operation. When operating the unit excercise caution when touching this
surface and ensure that external materials which may be adversely affected by heat
are not in contact with it. There is a Hot Surface label (see diagram) attached to the
aforementioned surface of the product.

© 2006 Wohler Technologies Inc. ALL rights reserved 3
AMP-S8 Series+ User Manual P/N 821640 Rev-B
Sect. 1: General Features and Specifications
General Features
and Specifications
Quick Start Guide
Description
Features
Applications
Specifications
Installation
Section 1
When in Normal Operational Mode, the software for this family of products allows three fast channel selection modes;
Single,Pair, and Downmix. See above images for button locations. Select channels as follows:
Single Channel Select: Channel selection for the left and right speakers are controlled independently.
Hold down the FN Button, press and release the SINGLE Button. Use the L-UP and L-DOWN Buttons to cycle up
or down through the channels to be assigned to the left speaker channel. Use the R-UP and R-DOWN Buttons to
cycle up or down through the channels to be assigned to the right speaker channel. Channels are selected for
monitoring as they are displayed in the LCD.
Pair Channel Select: Channels are selected in pairs (1/2, 3/4, 5/6, or 7/8) with the first channel in the pair
routed to the left speaker and the second routed to the right speaker.
Hold down the FN Button, press and release the PAIRS Button. Use the R-UP and R-DOWN Buttons or L-UP
and L-DOWN Buttons to cycle up or down through the channel pairs assignable to the left/right speaker
channels. Channels are selected for monitoring as they are displayed in the LCD.
Downmix Select: Pre-configured downmixes of multi-channel selections may be selected.
Hold down the FN Button, press and release the DOWNMIX Button. Use the R-UP and R-DOWN Buttons or
L-UP and R-UP Buttons to cycle up or down through the downmix selections. Downmixes are selected for
monitoring as they are displayed in the LCD.
Wohler AMP-S8 Series+
Quick Start Guide
Use the information below to quickly set up your Wohler AMP-S8 Series+ product for immediate use. The illustration
below is provided to help you locate and identify the programming buttons described in this quick start guide. See page
25 for more information about selecting channels and downmixes for monitoring.
MUTE
R
UP
DOWN
SINGLE
UP
DOWN
PAIRS
DOWNMIX
INPUT
GROUP
SETUP
ENTER
L
FN
O
ESC
LEFT RIGHT
UP INPUT DOWN GROUP UPMUTE DOWN
SINGLE
FN
DWNMXPAIRS SETUP ENTERESC
SINGLE
Button PAIRS
Button
DOWNMIX
Button
FN
Button
L UP and
L DOWN
Buttons
R UP and
R DOWN
Buttons
L UP and
L DOWN
Buttons
R UP and
R DOWN
Buttons
SINGLE
Button
PAIRS
Button
DOWNMIX
Button
FN
Button
AMP1-S8 (1U)
AMP2-S8 (2U)

© 2006 Wohler Technologies Inc. ALL rights reserved
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AMP-S8 Series+ User Manual P/N 821640 Rev-B
AMP-S8MDA Features
AMP-S8SDA Features
AMP-S8HDA FeaturesGeneral AMP-S8 Series+ Features
Features
The AMP-S8 Series+ audio monitoring products are a complete, exceptionally high quality SD-SDI/HD-SDI, AES/EBU and
Analog stereo audio monitoring solution. The AMP-S8 Series+ comprehensive monitoring features are available in either a
compact one (1U AMP1) or two (2U AMP2) rackspace cabinet. A significant feature is the ability to process and monitor up to
eight channels from an HD-SDI and/or SD-SDI bitstream, two sets of four AES/EBU signal pairs (balanced and unbalanced), or
eight Analog channels. Eight high-resolution 53-segment tri-color LED bargraph audio level meters provide accurate and instanta-
neous visual level monitoring at a glance. A convenient high-contrast LCD display on the front panel shows the user settings and
status (as currently selected), type of signal, channel selection, mute status, and alternately, phase/correlation. Input presets may be
configured and easily recalled by the user.
Additionally, the unique design of the AMP-S8 Series+ provides optimally focused sound in an Ultra Near Field (1 to 3 feet)
environment, which allows higher SPL for the operator while reducing overall ambient sound and adjacent bay crosstalk.
There are four different configurations which vary according to SDI input type and configuration; the AMP-S8DA (no SDI), the
AMP-S8SDA (270 Mbps SDI), the AMP-S8HDA (1.5 Gbps HD-SDI), and the AMP-S8MDA (270 Mbps and 1.5 Gbps HD-
SDI).
• 1U or 2U Rack Spaces: highest fidelity in minimum size
• AES/EBU, and Analog signal monitoring
• Four de-embedded AES balanced or unbalanced outputs
(8 channels) from two selected SDI Groups
• Four AES/EBU balanced inputs and loop-throughs on a DB-
25 connector
• Eight Analog inputs on a balanced DB-25 connector
• Eight Analog outputs on a balanced DB-25 connector
• Comprehensive multi-channel to stereo downmix capability
• Unit configuration stored while unit is switched off
• Storage for ten preset monitoring settings for easy recall
• Phase (polarity) correlation display of selected channels
• LCD status display on front panel
• Volume and balance controls
• Eight high-resolution 53-segment tri-color LED bargraph
level meters with simultaneous PPM dot over VU bar
• Headphone output
• Composite NTSC or PAL outputs from SDI input option (for
SDI or HD-SDI models)
• Software is field upgradable
AMP-S8 Series+
Powered Analog/Digital Audio Monitor
• Two SDI inputs (either SD-SDI or HD-SDI) with reclocked
output of selected input
• Single SDI input option available for cost savings
• Demuxes any two SD-SDI or HD-SDI groups to AES/EBU
• Select sources from AC-3 carried on SD-SDI , HD-SDI, or
AES/EBU for metering/monitoring
• AES output from HD/SD-SDI input
• NTSC/PAL video encoder option available
Description
Section 1: General Features and Specifications
• Two HD-SDI inputs with reclocked output of selected input
• Single HD-SDI input option available for cost savings
• Demuxes any two HD-SDI groups to AES/EBU and Analog
• Select sources from HD-SDI, AES/EBU, orAnalog for
metering/monitoring
• AES output from HD-SDI input
• NTSC/PAL video encoder option available
• Two SDI inputs with reclocked output of selected input
• Single SDI input option available for cost savings
• Demuxes any two SDI groups to AES/EBU and Analog
• Select sources from SD-SDI, AES/EBU, or Analog for
metering/monitoring
• AES output from SD-SDI input
• NTSC/PAL video encoder option available
• Same as other models except no SDI input option
AMP-S8DA Features
tm

© 2006 Wohler Technologies Inc. ALL rights reserved 5
AMP-S8 Series+ User Manual P/N 821640 Rev-B
Applications
The AMP-S8 Series+ is ideally suited to provide high quality multi-channel digital and analog audio monitoring in a very compact
form. Ideal for use in VTR bays, mobile production vehicles, teleconferencing installations, multimedia systems, satellite links,
cable TV facilities, and on-air radio studios. Designed and manufactured in the U.S.A., the AMP-S8 Series+ is backed by a strong
warranty and a satisfaction guaranteed return policy.
Section 1: General Features and Specifications
Analog Input Impedance:
AES Input Configuration:
AES Termination:
Analog Input Overload:
Analog Reference:
Digital Reference:
Meter Dynamics (AES Scale):
Level Meter Scale (standard):
AES Input Sampling Rate:
D to A Converter:
Peak Acoustic Output:
(@ 2 ft.)
Acoustic Distortion:
Response, Sixth Octave:
Distortion, Electrical:
Hum and Noise, Analog:
Power Output,
High Frequency:
Low Frequency:
27K Ω balanced, minimum
110 Ωbalanced, 75 Ωunbalanced
DIP switch selectable on rear panel
+24 dBu balanced
+8, +6, +4, or 0 dBu
-20, -18, or -9 dBFS
VU and PPM
AES*
32-48 KHz, auto-select
24-bit low jitter
104 dB SPL
6% or less at worst case frequencies
above 140 Hz including cabinet reso-
nance; typically less than 1.5%
80Hz – 18 KHz +/- 5 dB
(-10 dB @ 55 Hz, 21 kHZ)
< 0.15% at any level below limit threshold
Better than 68 dB below full output
6 W RMS (each channel)
14 W RMS
Converted Analog
Out THD:
Magnetic Shielding:
Input Connectors:
Power Consumption
(less than):
AC Mains Input:
Chassis Dimensions
(H x W x D):
Weight:
< 0.008%
Less than 1 Gauss any adjacent
surface
AES: D-SUB 25, BNC x4
SD-SDI, HD-SDI: BNC x2
Analog: D-SUB 25 ("Tascam"
pin-out on all D-sub connectors)
72 W
100-240 VAC, 50-60 Hz
3.5 x 19 x 12.5 inches
89 x 483 x 317.5 mm
Depth is 14 inches (355.6 mm)
including controls/knobs
18 lbs. (8.2 kg)
Units are certified to meet, at time of manufacture, all currently applicable product safety and EMC requirements, such as those of CE.
0 dbu ref. 0.775V RMS. Features and specifications subject to improvement without notice.
Specifications
Other level meter scales are available for specification at time of
manufacture including BBC, DIN, etc. Contact Wohler for more
information concerning alternate scales.
*

© 2006 Wohler Technologies Inc. ALL rights reserved
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AMP-S8 Series+ User Manual P/N 821640 Rev-B
Mounting
The unit should be mounted where convenient for operating persons, ideally at approximately ear level for best high frequency
response. Its superior magnetic shielding eliminates concerns about locating it adjacent to most types of CRT monitors,
including even high-resolution color monitors.
Heat Dissipation
Heat dissipated by the speaker amps is conducted directly to the left side of the chassis; no special considerations for cooling are
necessary as long as the ambient temperature inside the rack area does not exceed approximately 40°C (104°F).
Sympathetic Vibration
Sympathetic vibration from other equipment (cables, etc.,) in the rack may be serious enough to interfere with the unit’s sound
quality out in the listening area. The use of thin card stock and/or felt or foam weather-stripping type materials between adjacent
vibrating surfaces, or tying up loose cables, etc., may be required to stop vibrations external to the unit.
Mechanical Bracing
Even though the 2U models are fairly heavy, the chassis is securely attached to the front panel at eight points along its surface, not
just at the four corners of the chassis ears. This feature will reduce or eliminate rear bracing requirements in many mobile/portable
applications. The weight of internal components is distributed fairly evenly around the unit.
Audio Connections and Cable Recommendations
Connection of the audio feeds is straightforward. Please refer to the system interconnect block diagram on page 40 for
clarification of the general signal paths into and out of the AMP-S8 Series+ units.
There are recommended limits to the length of cable that should be used for feeding HD-SDI signals sources to the HD-SDI inputs
of the AMP-S8HDA and AMP-S8MDA units. Recommendations are as follows:
Using Belden 1694A cable (or equivalent),
HD-SDI input2 (IN 1 and IN 2) = Up To 150 Meters (492 feet)
Note: The connections of all DB-25 connectors are compatible with Tascam*DB-25 to XLR cable assemblies. Consult the
factory for availability. All rear panel connectors are female except for the XLR connectors. *The Tascam trademark is owned
by Teac Inc.
Electrical Interference
Care should be exercised to apply proper input termination settings and avoid mismatched cable types and other similar causes of
undesired reflections in digital signal systems. If severe enough, such reflections can result in corruption of the digital datastream.
As with any audio equipment, maximum immunity from electrical interference requires the use of shielded cable; however,
satisfactory results can sometimes be obtained without it. The internal circuitry common is connected to the chassis.
AC Power
The unit's AC mains connection is via a standard IEC inlet, with safety ground connected directly to the unit's chassis. The
universal AC input (100-240VAC, 50/60Hz) switching power supply is a self-resetting sealed type, with automatic over-voltage
and over-current shutdown. There is no user-replaceable fuse in either the primary or secondary circuit.
Installation
Section 1: General Features and Specifications

© 2006 Wohler Technologies Inc. ALL rights reserved 7
AMP-S8 Series+ User Manual P/N 821640 Rev-B
Operation
Front Panel Features
Rear Panel Features
Introduction to the User Interface
User Interface Features
User Interface Function Guide
Section 2
NOTE: Throughout the manual, the following terms are used to refer to Serial Digital (SDI) signals:
•SD-SDI = refers only to standard SDI (270 Mbps).
•HD-SDI = refers only to high-definition SDI (1.5 Gbps).
•SDI = refers to either standard SDI (SD-SDI, 270 Mbps) or high defintion SDI (HD-SDI, 1.5 Gbps).

© 2006 Wohler Technologies Inc. ALL rights reserved
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AMP-S8 Series+ User Manual P/N 821640 Rev-B
4
5
6
7
8
9
1
2
3
Please refer to Figure-2a on the facing page to familiarize yourself with the front panel controls and indicators of the AMP-S8
Series+ units. The following sections describe the functions of each of the various controls and indicators found on the front panel
and are referenced, by number, to Figure-2a.
Front Panel Features
Section 2: Operation
Speakers
The AMP2-S8 (2U) models feature two mid-range speakers (left and right) and one woofer speaker, while the AMP1-S8
(1U) models feature two mid-range speakers (left and right) and two woofer speakers.
All models of the AMP-S8 Series+ contain high performance transducers driven by three power amplifiers; two amplifier/
driver combinations handle midrange and high frequency information in the left and right (stereo) speaker channels, while the
third channel reproduces and sums the left and right channel information below the 500 Hz crossover point in the single
woofer (bass) speaker channel. Note that the woofer channel is NOT a dedicated LFE (subwoofer) or Center channel.
Headphone Jack
This jack accepts a standard 1/4” phone type stereo plug. Select the headphone audio sources as you would for the internal
speakers. When you plug in headphones the speakers will mute.
CHANNEL MIX (1-8) or Preset Select Buttons (1-4)
These buttons are used to select the channels to be summed into either or both speaker channels or to create and recall
presets when used in conjunction with the FN Button.See Item 7a on page 18 for a full description of the function of the
CHANNEL MIX Buttons.
Bargraph Meter Brightness Controls (Left and Right)
The brightness of the bargraph meters is adjusted using these two recessed trimpot controls. The left control adjusts the
brightness of the left four LED bargraphs and the right control adjusts the brightness of the right four bargraphs. Use a small
flat blade screwdriver or similar tool to adjust these controls. Clock-wise rotation increases the brightness.
Volume Control
This controls the loudness of the audio reproduced by the internal speaker channels or connected headphone.
CHANNEL MIX LEDs (1-8)
The AMP2-S8 (2U) model features dedicated LEDs above each bargraph, while the AMP1-S8 (1U) model uses the top
LED segment of each bargraph to indicate the channel mix selections. These LEDs are used to indicate the speaker mix of
selected channels. See Item 3 for channel mix information. See Item 7b on page 18 for a description of the function of the
CHANNEL MIX LEDs.
User Interface Controls and LCD Display
See the User Interface Features section starting on page 18 and the User Interface Function Guide starting on page 23
for instructions on the use of the User Interface Buttons and the LCD Display.
Audio Level Meters (1-8)
Source channels 1-8 are displayed via eight audio level meters (four on the left side of the front panel; four on the right side).
Meters are high-resolution LED bargraph displays with PPM dot over VU bar ballistic characteristics. In the AMP2 model these
level meters are 53-segment bargraphs with a dynamic range of -66 dB. In the AMP1 models these level meters are 26-segment
bargraphs with a dynamic range of 60 dB.
Balance Control
This control changes the volume balance between the left and right speaker channels. Please note that this control attenuates
the signal from the source, so that the left and right bass frequencies (summed together and reproduced in the woofer
channel) will respond to balance adjustments in tandem with the left and right speaker channels. See page 39 for more
information concerning the AMP-S8 Series+ balance control characteristics.

© 2006 Wohler Technologies Inc. ALL rights reserved 9
AMP-S8 Series+ User Manual P/N 821640 Rev-BSection 2: Operation
Figure-2a: Front Panel Features
AMP1-S8 AMP2-S8

© 2006 Wohler Technologies Inc. ALL rights reserved
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AMP-S8 Series+ User Manual P/N 821640 Rev-B
B
C
D
E
A
Please refer to Figure-2b and Figure-2c on the following pages to familiarize yourself with the rear panel features of the AMP-S8 Series+
units. The following sections describe the functions of each of the various features found on the rear panels and are referenced, by letter, to
Figure-2b and Figure-2c.
Rear Panel Features
Power Connector
Attach a standard IEC-320 power cord between this connector and mains power.
OPT A - Rotary Switch (2U MDA Model only) or Reset Button (2U SDA Model only)
In the 2U SDA model, this opening features a recessed push-button with a momentary reset function for the SD-SDI input
module. Pressing the button with a small screwdriver or other tool will reset the SD-SDI input functions of the SDA unit.
In the 2U MDA model (but not HDA model) with the CVBS Video Output option installed (Item D), this opening features
a 10-position rotary switch for selecting related functions as shown in the following table:
NOTE: Throughout the manual, the following terms are used to refer to Serial Digital (SDI) signals:
•SD-SDI = refers only to standard SDI (270 Mbps).
•HD-SDI = refers only to high-definition SDI (1.5 Gbps).
•SDI = refers to either standard SDI (SD-SDI, 270 Mbps) or high defintion SDI (HD-SDI, 1.5 Gbps).
Section 2: Operation
OPT B (2U) or OPT (1U) Rotary Switch
The OPT B (2U models) or OPT (1U models) opening features a 10-position rotary switch, which is reserved for future
options and should be left at the factory position 1.
CVBS Video Output (From SDI) Connector (Option for 2U SDA and MDA Models only)
This option is available only on the 2U rack SDA and MDA models.When the CVBS Video Out option is specified, a
female BNC connector installed here outputs CVBS (composite) video encoded from the selected SDI input (Item
E). HD-SDI signals are scaled for proper representation in composite video format. See Item B for how to select the type
of CVBS video output for the MDA model. When this option is installed, a select switch is also installed to allow selection
of the 910213 video scaler module for communication through the RS232 #2 connector (Item G).
This output functions regardless of other selection settings. This feature enables encoding of the SDI signal to CVBS
independent of other monitoring functions (as long as a valid SDI signal is present at the associated input).
SDI Input Connectors - IN1 and IN2 (SDA, HDA, and MDA Models only)
These BNC inputs accept SDI digital audio signals as follows (the DA model does not feature SDI capability):
•AMP-S8SDA = SD-SDI only (Standard, 270 Mbps)
•AMP-S8HDA = HD-SDI only (High-Definition, 1.5 Gbps)
•AMP-S8MDA = HD-SDI or SD-SDI (High-Definition, 1.5 Gbps or Standard, 270 Mbps)
Note that PCM signals embedded within an SDI bitstream are automatically de-embedded for montoring through the unit.
When set to positions 1,2,3,or 4,the signals from the CVBS Video Output option (Item D)and the video supplied to
the internal LCD will be the format described for each position in the table (NTSC or PAL) regardless of the input format.
When set to positions 3or 4,HD-SDI input signals are letterboxed, but SD-SDI input signals are not. Setting the switch to
positions 8or 9, will force a hardware reset on the video scalar (919213)and audio de-embedder (919212) modules.

© 2006 Wohler Technologies Inc. ALL rights reserved 11
AMP-S8 Series+ User Manual P/N 821640 Rev-BSection 2: Operation
Figure-2b: Rear Panel Features
AMP2-S8DA
AMP2-S8SDA,
HDA, or MDA

© 2006 Wohler Technologies Inc. ALL rights reserved
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AMP-S8 Series+ User Manual P/N 821640 Rev-B
F
G
H
Rear Panel Features
SDI Re-Clocked Output Connector (SDA, HDA, and MDA Models only)
This connector outputs a re-clocked copy of the SD-SDI or HD-SDI signal fed to the SDI Input Connector (Item E)
selected for monitoring (IN 1 or IN 2). However, when an SDI input source is not selected for monitoring, the re-clocked output
will monitor the SDI IN 2 input by default. Also, the de-embedded AES Unbalanced Output Connector ( Item M, page
14) or optional AES Balanced Output Connector ( Item N, page 15) will monitor the last selected SDI audio group pair
from the last selected SDI input.
This output functions regardless of other selection settings. This feature enables the output of the re-clocked SDI signal
independent of the units other monitoring functions (as long as a valid SDI signal is present at the associated input).
RS232B Connector and Select Switch (2U SDA, HDA, and MDA Models only)
This connector is available only on the 2U rack AMP2-S8 models featuring SDI inputs (SDA,HDA, and MDA models).
This DB-9 connector is used for downloading programming, setup, and diagnostic information into and out of the 919212
audio de-embedder module.However, if the CVBS Video Output option is installed (Item D) in an SDA or MDA model,
then the select switch is installed to allow selection of the optional 910213 video scaler module for communication through
the RS232B connector as well. When installed, the switch is placed in the UP position to access the 910213 video scaler
module and in the DOWN position to access the 919212 audio de-embedder module.
Unbalanced AES / PCM Input Connectors (1-4) (AES1) and Termination
In this input section, there are four unbalanced female BNC input connectors (1,2,3, and 4) which accept standard AES
and PCM formatted signals. These inputs may be selected for monitoring by using the INPUT Button (Item 7i, page 21).
These inputs are referred to as AES1 in the LCD display.
If you are connecting downstream equipment to these inputs in a loop-through configuration, then you should Unterminate
(switch UP) the selected input connector. If you are not connecting downstream equipment, then you should Terminate
(switch DOWN) the selected input connector. Note that these termination DIP switches are also used to set the termination
of the Balanced AES/PCM Inputs (Item I) as well. See the diagram below for settings.
Balanced AES / PCM Input and Loop-Through Connector (AES2)
This female DB-25 connector accepts balanced AES signals. Inputs are internally connected to the loop-through outputs.
See diagram below for pin-out information. These inputs may be selected for monitoring by using the INPUT Button
(Item 7i, page 21). These inputs are referred to as AES2 in the LCD display.
Section 2: Operation
I
1 = CH-1/2
2 = CH-3/4
3 = CH-5/6
4 = CH-7/8
If you are connecting downstream equipment to the AES Loop-Through outputs of this connector, then you should
unterminate (switch UP) the selected input by setting the appropriate Termination DIP Switch (Item H). If you are not
connecting downstream equipment, then you should terminate (switch DOWN) the selected input connector. See the
diagram under Item H for termination settings.
The connections for this connector are compatible with Tascam*DB-25 to XLR cable assemblies. Consult the factory for
availability.

© 2006 Wohler Technologies Inc. ALL rights reserved 13
AMP-S8 Series+ User Manual P/N 821640 Rev-B
Figure-2c: Rear Panel Features
AMP1-S8DA
AMP1-S8SDA,
HDA, or MDA

© 2006 Wohler Technologies Inc. ALL rights reserved
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AMP-S8 Series+ User Manual P/N 821640 Rev-B
M
Analog Input Connector
This female DB-25 connector accepts standard balanced, line level analog signals. See diagram below for pin-out information.
Metered Analog Output Connector
This DB-25 connector outputs analog signals as de-embedded from the selected sources or downmix, which are eligible for
conversion to analog. See the diagram under Item J above for pin-out information.
NOTE: The Analog Output Preference entry within the Setup menu is used to determine how this connector outputs
the channel mix when a DM1,DM2, or DM3 downmix selection is enabled. The default setting is Downmix, which
outputs the channel mix with individual channel scaling (gain settings) intact as determined by the selected downmix (DM1,
DM2, or DM3). However, if Discrete is selected, then all channels within the downmix are output from these connectors
at full gain without scaling of the channels as determined by the selected downmix. See Analog Output Preference (A-
OutPref) section on page 30 for information on how to set this parameter.
Reference Setting Rotary Switch (1-10)
This recessed 10-position rotary switch is used to set the Analog and Digital Reference Levels for the units level meters, as well
as selecting the Software Upgrade function. In the table shown, the Analog Reference Level (Analog, left column) is the
analog input level needed to turn on the bargraph segment at the associated Digital Reference Level (Digital, right column)value.
This is also the location on the bargraph level meter where the color transitions from GREEN to AMBER. Example: Choosing
position 2(0 dBu = -20 dBFS) means an analog input level of 0 dBu will light up the LED segment associated with the digital -20
dBFS value on the bargraph meter and also transition from GREEN to AMBER at that segment.
K
J
L
Rear Panel Features
Section 2: Operation
Selected/Downmix Analog Output Connectors (Left and Right)
These two 3-pin male XLR connectors are analog outputs of the channel mix (or downmix) source as selected for the left and
right speaker channels. Pinout conections are: Pin-1= Ground (shield), Pin-2= High (+), Pin-3= Low (-).
NOTE: The Analog Output Preference entry within the Setup menu is used to determine how these connectors
output the channel mix when a DM1,DM2, or DM3 downmix selection is enabled. The default setting is Downmix,
which outputs the channel mix with individual channel scaling (gain settings) intact as determined by the selected
downmix (DM1,DM2, or DM3). However, if Discrete is selected, then all channels within the downmix are output
from these connectors at full gain without scaling of the channels as determined by the selected downmix. See
Analog Output Preference (A-OutPref) section on page 30 for information on how to set this parameter.

© 2006 Wohler Technologies Inc. ALL rights reserved 15
AMP-S8 Series+ User Manual P/N 821640 Rev-B
Q
P
AES Unbalanced Output (From SDI Input) Connector (Standard SDA, HDA, and MDA)
AES signals de-embedded from the selected SDI Input,IN1 or IN2 (Item E, page 10) are output from this female
HD-15 connector, which is configured for unbalanced 75ΩΩ
ΩΩ
Ωimpedance connections. See the table and diagram
below for pinout information. See Item O for instructions on how to replace this standard unbalanced connector with
the optional integrated DB-25 balanced connector.
AES Balanced Output (From SDI Input) Connector (Option SDA, HDA, and MDA)
AES signals de-embedded from the selected SDI Input,IN1 or IN2 (Item E, page 10) can be output from this DB-25
connector, which is configured for balanced connections (110 ΩΩ
ΩΩ
Ωimpedance). When installed, this balanced DB-25
connector replaces the unbalanced HD-15 connector in Item N. Pinout information for the balanced DB-25 connector is
shown below.
N/C
13
N/C
G = Ground
- = Cold
+ = Hot
2325 24
1112
22 21
8910
N/CN/C N/C
15
+
5
20 19 18
67
17 16
3
4
G
1
G
-+
32
G
--+
14
12
4
G
-+
SDI Channels
AES Output of
1 = CH-1/2
2 = CH-3/4
3 = CH-5/6
4 = CH-7/8
Rear Panel Features
Section 2: Operation
O
N
Installing the Optional DB-25 Balanced Connector:
The female DB-25 balanced output option may be installed by qualified service personel without need for additional
parts as follows:
1) Remove power from the unit.
2) Remove the top cover from the chassis of the AMP-S8 Series+ unit (set the screws aside for later
reassembly).
3) The standard unbalanced HD-15 connector is attached to the rear panel by a plate. Under this connector and
plate is the cutout for the optional DB-25 connector. Inside the unit, the HD-15 connector (Item N) is
connected to an output PCB module (919224). Unplug the female DB-25 connector (Item O) from the other
end of this module. Note that the DB-25 connector terminates an internal ribbon cable.
4) Remove and set aside the two screws, nuts, and washers from the HD-15 connector plate attached to the rear
panel and remove the connector/plate/module assembly from the unit.
5) Use the two screws, nuts, and washers removed from the disassembled HD-15 connector plate to install the
DB-25 connector into the larger connector cutout now revealed.
6) Reassemble the top cover to the chassis.
NOTES:
•The DB-25 balanced option may be specified at time of order and the conversion performed at the factory.
•Once conversion to a balanced DB-25 connector is done (following steps 1-6above), a special dongle is
available which may be plugged into the DB-25 connector to easily convert it (back) to an unbalanced HD-15
connector. Contact Wohler Technologies for more information on this dongle.
RS232A Input/Output Connector
This DB-9 connector is used for downloading programming, setup, and diagnostic information into and out of the unit.
Remote Connector (Option for 2U Models only)
This option is available only on the 2U rack AMP2-S8 models. This connector is not installed in standard 2U models
and is available for installation with a retrofit kit, or as an option when ordering. When installed, it allows remote control
over input source selection or other other aspects of the system as may be specified in a special order. Contact
Wohler sales for special order inquiries (email: [email protected]).

© 2006 Wohler Technologies Inc. ALL rights reserved
16
AMP-S8 Series+ User Manual P/N 821640 Rev-B
Introduction to the User Interface
General Monitoring Characteristics and Capabilities
Units are factory-configured for ALL user settings to be non-volatile. Whenever power to the unit is cycled (Off/On) the unit
will restore itself, so that each user setting such as Channel Selection(s), Input Type, etc., are automatically restored to the
units previous factory setting. However, the unit may be configured instead to have a fixed initial input type (Analog,AES,
SD-SDI, or HD-SDI) when the unit is turned on, with all other settings being non-volatile (revert to previous settings). See
Startup section on page 30 for more information about this setting. Any two of the eight metered channels (or a downmix of
from one to all eight) may be reproduced using the internal amplifiers and loudspeakers. Each of the AMP-S8 Series+ models
is capable of visually monitoring audio levels for the eight channels of the following source types:
•SD-SDI 1&2or HD-SDI 1&2: Two 4-channel audio groups
•AES1 or AES2:Four PCM bitstreams (each equivalent to 2
analog channels)
•Analog:Eight Channels
AMP-S8MDA
•HD-SDI 1&2: Two 4-channel audio groups
•AES1 or AES2:Four PCM bitstreams (each equivalent to 2
analog channels)
•Analog:Eight Channels
AMP-S8HDA
•SD-SDI 1&2: Two 4-channel audio groups
•AES1 or AES2:Four PCM bitstreams (each equivalent to 2
analog channels)
•Analog:Eight Channels
AMP-S8SDA
•AES1 or AES2:Four PCM bitstreams (each equivalent to 2
analog channels)
•Analog:Eight Channels
AMP-S8DA
Section 2: Operation
There are two sections that may be referred to when learning how to operate the AMP-S8 Series+ user interface controls; the
User Interface Features section starting on page 18, which describes the units functions by feature and the User interface
Function Guide section starting on page 23, which describes the operation of the unit by function and also describes operation
in greater detail. Navigation, selection, and adjustment are performed by pressing the user interface buttons on the front panel
of the unit (see Figure-2d, page 17). The LCD Display provides the visual feedback and status indication for these operations.
Multi-Mode Color Codes
Amode, within the context of this manual, is understood to mean a state in which the monitor behaves a certain way. For
instance, in Setup Mode the AMP-S8 Series+ monitor allows a number of "setup" parameters to be accessed and adjusted.
Most of the User Interface control buttons are multi-functional; when pressed while the unit is in one mode they cause a
certain effect, but when pressed while the unit is in a different mode they cause a different effect. On the AMP-S8 Series+
front panel itself, color-coding is used to help identify the different functions of each button when used in different modes;
WHITEWHITE
WHITEWHITE
WHITE for Normal Operational Mode,BLUE for buttons used in conjunction with the FN Button, and YELLOW for
button functions when in SETUP Mode.
Within this manual, the printed names of controls are color-coded according to function. For instance, Item 7c (page 18) can
alternately be referred to as the L UP Button,SINGLE Button, or Button , depending on which mode the unit is in when
it is pressed.
All function descriptions in the User Interface Features section have color-coded dots next to them which indicate which
mode the function operates in. These dots are color coded as follows:
(WHITE) = button function when in Normal Operational Mode.
(BLUE) = button function when used in conjunction with the FN Button.
(YELLOW) = button function when used for Setup Mode navigation and selection.
Default Operational Modes
The basic default operational state of the AMP-S8 monitor is referred to as the Normal Operational Mode. From this mode,
sub-modes are accessed. It is also in this mode that current operational status is displayed in the LCD display. The diagram
on page 17 (Figure-2c) shows an overview of the major operational modes that are available.
Using Buttons for Selection, Display, and Navigation
Buttons are pressed one at a time or in combination to enter sub-modes and set parameters. These are explained in detail in the
User Interface Features and Function Guide sections. The Setup Menu Navigation Flow Diagram on page 31 (Figure-
2e), provides a graphical overview of the operation and function of the buttons as used in Setup Mode.

© 2006 Wohler Technologies Inc. ALL rights reserved 17
AMP-S8 Series+ User Manual P/N 821640 Rev-BSection 2: Operation
Figure-2c: Major Operational Modes, Submodes, and Parameters
Introduction to the User Interface
Figure-2d: Front Panel User Interface Reference

© 2006 Wohler Technologies Inc. ALL rights reserved
18
AMP-S8 Series+ User Manual P/N 821640 Rev-B
7c
7b
7a
User Interface Features
Please refer to Figure-2d on page 17 to familiarize yourself with the front panel user interface controls of the AMP-S8 Series+ units. The
following sections describe these features and are referenced, by number/letter, to Figure-2d. For multi-function controls, a color-coded
dot identifies the mode in which a particular function operates; GRAY dot ( ) = Normal Operational Mode, BLUE dot ( ) =
FUNCTION (FN) Modes, YELLOW dot ( ) = Setup Mode). The user should refer to the User Interface Function Guide starting on
page 23 where operation is described in greater detail and contents are referenced by function rather than feature.
CHANNEL MIX 1-8 (PRESETS 1-4) Buttons
Configuring a CHANNEL MIX for Monitoring: > CHANNEL MIX Button 1-8
The mixing (summing) feature is activated whenever any CHANNEL MIX Button is pressed, and is indicated by the
selection display showing MIX in the upper right and left of the display.
Each repeated press of a Channel Mix Button sequencially assigns that channel to the left, both, right, or neither speaker
channel. With each successive button press, the color of the associated CHANNEL MIX LED (Item 7b), and the mixing/
routing of that channel, cycles through the following sequence: 1) GREEN (to left speaker only), 2) GREEN/AMBER
alternating (to both left and right speakers), 3) AMBER (to right speaker only), 4) OFF (not mixed or routed into either
speaker).
Recalling and Saving Presets: > FN Button + PRESETS Button 1-4
Press and hold the FN Button and then press the corresponding PRESETS Button (1-4). At the prompt, press the
NTER Button to accept the preset. See the Save Preset section on page 29 for how to save the current configuration as
a preset. See pages 28-30 for more information about creating, naming, recalling, and erasing input presets within Setup
Mode.
CHANNEL MIX LEDs 1-8
These LEDs are used to indicate the speaker mix of channels as selected when using the CHANNEL MIX Buttons (Item
7a). See CHANNEL MIX Selection section on page 25 or Item 7a above for a description of the function of these
indication LEDs.
L UP (SINGLE or ) Button
Selection Navigation Using the UP and DOWN Buttons: > L UP (or L DOWN) Button
The L UP and L DOWN (and R UP and R DOWN)Buttons are used to cycle through and select different channels or
channel combinations, depending on which Selection Mode is selected. See Single Channel Selection,Paired Channel
Selection, and Downmix Selection on page 25 for more information about using these buttons for channel selection.
Making Single Channel Selections: > FN Button + SINGLE Button
Single Channel Select Mode is enabled by pressing and holding the FN Button (Item 7j)and then pressing the SINGLE
Button. Press the L UP or L DOWN Buttons to cycle up or down through each channel selection for the left speaker;
press the R UP or R DOWN Buttons to cycle up or down through each channel selection for the right speaker.
Cycling Through Selections in Setup Mode: > (or ) Button
In Setup Mode, the Button is used to cycle upward through selections, and the Button is used to cycle downward.
Also see Enabling Setup Mode (page 28) and the Setup Menu Navigation Flow Chart (Figure-2e, page 31).
L DOWN (PAIRS or ) Button
Selection Navigation Using the UP and DOWN Buttons: > L DOWN (or L UP) Button
The L UP and L DOWN (or R UP and R DOWN)Buttons are used to cycle through and select different channels or
channel combinations, depending on which Selection Mode is selected. See Single Channel Selection,Paired Channel
Selection, and Downmix Selection on page 25 for more information about using these buttons for channel selection.
Making Paired Channel Selections: > FN Button + PAIRS Button
Paired Channel Select Mode is enabled by pressing and holding the FN Button and then pressing the PAIRS Button.
After entering this mode, the L UP and L DOWN Buttons or R UP and R DOWN Buttons are used to cycle up or down
through channel pair selections 1/2,3/4,5/6, or 7/8 each channel being assigned, respectively, to the left and right speakers.
Cycling Through Selections in Setup Mode: > (or ) Button
In Setup Mode, the Button is used to cycle downward through selections, and the Button is used to cycle upward.
Also see Enabling Setup Mode (page 28) and the Setup Menu Navigation Flow Chart (Figure-2e, page 31).
Section 2: Operation
7d

© 2006 Wohler Technologies Inc. ALL rights reserved 19
AMP-S8 Series+ User Manual P/N 821640 Rev-B
7g
R DOWN (ENTER) Button
Selection Navigation Using the UP and DOWN Buttons: > R DOWN (or R UP) Button
The R DOWN or R UP (and L DOWN or L UP)Buttons are used to cycle through and select different channels or
channel combinations, depending on which Selection Mode is selected. See Single Channel Selection,Paired Channel
Selection, and Downmix Selection on page 25 for more information about using these buttons for channel selection.
Using the ENTER Button:
When in Setup Mode, The ENTER Button and is pressed to accept menu selections. Also see Enabling Setup Mode
(page 28) and the Setup Menu Navigation Flow Chart (Figure-2e, page 31) for more detailed information.
R UP (ESC) Button
Selection Navigation Using the UP and DOWN Buttons: > R UP (or R DOWN) Button
The R UP or R DOWN (and L UP or L DOWN)Buttons are used to cycle through and select different channels or
channel combinations, depending on which Selection Mode is selected. See Single Channel Selection,Paired Channel
Selection, and Downmix Selection on page 25 for more information about using these buttons for channel selection.
Using the ESC Button:
In Setup Mode, the ESCButton is used to exit, or back out of, any of the menus within Setup Mode without accepting
changes. Also see Enabling Setup Mode (page 28) and the Setup Menu Navigation Flow Chart (Figure-2e, page 31)
for more detailed information.
7f
7e
DM3 SD.SDI2 DM3DM3 SD.SDI2 DM3
DM3 SD.SDI2 DM3DM3 SD.SDI2 DM3
DM3 SD.SDI2 DM3
GP1 GP2GP1 GP2
GP1 GP2GP1 GP2
GP1 GP2
1 3 5 71 3 5 7
1 3 5 71 3 5 7
1 3 5 7
2 4 6 82 4 6 8
2 4 6 82 4 6 8
2 4 6 8
Source Status
(SD-SDI Input 2)
SDI Group
(Group #2)
Input Lock Status
(Channels 1, 2, 3, 4,
5, 6, 7, 8 Locked)
Mix Status
(Downmix
DM3)
SDI Group
(Group #1)
Mix Status
(Downmix
DM3)
LCD Display
In Normal Operational Mode the high-contrast LCD Display is used to report the currently selected channels for
reproduction along with selected source type,mix type, and any SD/HD-SDI audio group information (for products with
the SDI inputs). In other modes the display will indicate phase correlation and mute status. In Setup Mode, the display is
used to navigate menus, select parameters, and recall and name presets.
In normal operation (not muted), the Input Lock Status indicator (center of second line in display) is used to show the lock
status of selected digital inputs (including SDI sources). If all four input channel pairs are not locked (or connected), then
four short dashes are displayed in the center of the second line of the display. Each dash (-) indicates a position for
displaying the channel pairs available for monitoring. The display appearance and order (from left to right) is: 1/2,3/4,5/6
and 7/8. The input status is updated whenever a change in status is detected. The Input Lock Status is active only if one
of the digital sources is selected via the INPUT Button (Item 7i), and applies only to the digital source that is selected.
Status Display Examples - Input Sources:
User Interface Features
Section 2: Operation
MIX HD.SDI1 MIXMIX HD.SDI1 MIX
MIX HD.SDI1 MIXMIX HD.SDI1 MIX
MIX HD.SDI1 MIX
GP3 -- GP4GP3 -- GP4
GP3 -- GP4GP3 -- GP4
GP3 -- GP4
5 75 7
5 75 7
5 7
6 86 8
6 86 8
6 8
Source Status
(HD-SDI Input 1)
SDI Group
(Group #4)
Input Lock Status
(Channels 1, 2, 3, 4 Not
Locked; Channels 5, 6, 7, 8
Locked)
Mix Status
(Custom)
SDI Group
(Group #3)
Mix Status
(Custom)

© 2006 Wohler Technologies Inc. ALL rights reserved
20
AMP-S8 Series+ User Manual P/N 821640 Rev-B
7h GROUP (SETUP) Button
Selecting SDI GROUP: > GROUP Button
When either of the the SDI inputs are selected for monitoring, the GROUP Button allows the user to select which two 4-
channel SDI audio groups are available for monitoring and presented to the left and right banks of four Level Meter
Bargraphs (Item 8, page 8).
When the buttons are pressed relatively rapidly, the order of selections are as follows: 3/4,1/2,1/3,1/4,2/3,2/4,3/4. But
after a selection is chosen and left until the display flashes once, slower button presses will toggle between the Group 1/2
and Group 3/4 selections. After this, rapid presses will again initiate the cycling as previously described. Since the first
two selections are more common choices, this features allows easy toggling between them. See SDI Group Definition,
SDI GROUP Selection , and SDI SUBGROUP Selection on page 26-27 for more information.
Enabling Setup Mode: > FN Button + SETUP Button
Setup Mode is enabled by pressing and holding the FN Button and then pressing the SETUP Button. See Enabling
Setup Mode (page 28) and the Setup Menu Navigation Flow Chart (Figure-2e, page 31) for more detailed information.
This mode is used to change unit features. Entries are cycled through using the or Buttons and selections are
accepted by pressing the Button. The currently displayed menu may be exited by pressing the Button.
Current settable options in Setup Mode are:
• Recall Preset (RCallPSet)
• Save Preset (SavePSet)
• Preset Mode Enable (PSetMode)
• Erase Preset (ErasePSet)
• SDI Delay
• Surround Gain (Srnd Gain)
• Startup
• Analog Output Preference (A-OutPref)
After entering Setup Mode:
The display will indicate the software, version number, and the menu selection: Setup: RCallPSet (if presets are saved).
Press the Button, display changes to Setup: SavePSet
Press the Button (again), display changes to Setup: PSetMode (if presets are saved)
Press the Button (again), display changes to Setup: ErasePSet (if presets are saved)
Press the Button (again), display changes to Setup: SDI Delay
Press the Button (again), display changes to Setup: Srnd Gain
Press the Button (again), display changes to Setup: Startup
Press the Button (again), display changes to Setup: A-OutPref
Press the Button (again), to cycle (return) to the first selection; Setup: RCallPSet
To select the current option, press the Button.
To exit Setup Mode, press the Button.
Refer to Enabling Setup Mode (page 28) and the Setup Menu Navigation Flow Chart (Figure-2e, page 31) for more
detailed information.
Section 2: Operation
User Interface Features
NOTE: The RCallSet,PSetMode, and ErasePSet
options will not be available if a preset has not been
previously saved to the unit. See Save Preset
(SavePSet) on page 29 for how to save a preset of the
current unit configuration.