Wohler AMP1A, AMP1A-2S, AMP1A-LP, AMP1A-LP2S User Manual

AMP1A Series

AMP1A AMP1A-2S AMP1A-LP AMP1A-LP2S

(Document P/N 821526, Rev-D)

1U Stereo Audio Speaker Monitors

with Two or Optional Four Analog Audio Inputs,

Stereo Analog Outputs, and Optional Dual

10-Segment Level Meters and Phase Indication

User Manual

CONTENTS

Title and Contents ...........................................................

Introduction .......................................................................................

Section 1: General Features and Specifications........

Description and Features ......................................................................

Applications, General Specifications, and Other Options ......................

Section 2: Operation .......................................................

Installation ............................................................................................

Front Panel Features .............................................................................

Rear Panel Features ...............................................................................

Audio Amplifier and Speaker Configuration .......................................

Balance Control Characteristics ...........................................................

Section 3: Technical Information .......................................

1

2

3

4

5

7

9

10

12

14

14

15

General Technical Observations ..........................................................

Level Meter Gain Calibration and Display Mode Settings ....................

Bargraph Driver Circuit Description (919234) .....................................

Level Meter Specifications ..................................................................

Interconnect Block Diagrams ..............................................................

© 2006 Wohler Technologies Inc. ALL rights reserved

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Important Safety Instructions

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.

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.

Introduction

Congratulations on your selection of a Wohler Technologies product. 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:

Phone: [phone] Fax: [phone]

www.wohler.com [e-mail]

2

© 2007 Wohler Technologies, Inc. ALL rights reserved

Wohler Technologies, Inc.

31055 Huntwood Avenue

Hayward, CA 94544

US Toll-Free: 1-888-596-4537

AMP1A/-2S/-LP/-LP2S User Manual, P/N 821526, Rev-D

Section 1

General Features

and Specifications

Description

Features

Applications

General Specifications

Other Options

© 2006 Wohler Technologies Inc. ALL rights reserved

3

AMP1A/-2S/-LP/-LP2S User Manual, P/N 821526, Rev-D

AMP1A SeriesAMP1A Series

AMP1A Series

AMP1A SeriesAMP1A Series

1U Stereo Analog Audio Speaker Monitors

Including Models: AMP1A AMP1A-2S AMP1A-LP AMP1A-LP2S

WOHLER

TECHNOLOGIES

WOHLER

TECHNOLOGIES

POWER

AMP1A

POWER

AMP1A-2S

Section 1: General Features and Specifications

AMP1A

ANALOG AUDIO

MONITOR PANEL

AMP1A-2S

SOURCE

1

2

ANALOG AUDIO

MONITOR PANEL

SOURCE SOURCE

12

+

3
2
1
0
1
3
5
7
10
20

3
2
1

AVG

0
1
3
5
7
10
20

AMP1A-LP

ANALOG AUDIO
MONITOR PANEL

WOHLER

TECHNOLOGIES

POWER

AMP1A-LP

SOURCE SOURCE

12

+

3
2
1
0
1
3
5
7
10
20

3
2
1

AVG

0
1
3
5
7

10

20

SOURCE

1

2

AMP1A-LP2S

ANALOG AUDIO
MONITOR PANEL

WOHLER

TECHNOLOGIES

POWER

AMP1A-LP2S

Description

The AMP-1A Series of audio monitors provides self-powered, full-fidelity stereo monitoring in the smallest rack space possible.
All models in the AMP1A series contain five high performance transducers driven by three power amplifiers: two amplifier/driver
combinations handle midrange and high frequency information in stereo, while the third center channel reproduces information
below the 500 Hz crossover point.

All AMP-1A models come equipped with a ganged stereo volume control and balance pot, power indication LED, and headphone
output. Output limiter circuits are incorporated to protect the speakers, and extensive magnetic shielding allows placement
immediately adjacent to video monitors with no color impurities.

The AMP1A and AMP1A-LP models feature one pair of balanced XLR inputs and a pair of unbalanced RCA inputs with one pair
of XLR loop-through connectors for connecting to downstream equipment.

The AMP1A-2S and AMP1A-LP2S models feature two pairs of XLR inputs with a front panel toggle switch to select between the
two stereo sources. An additional pair of XLR connectors output the audio, as selected by the source select switch, for connecting
to downstream equipment.

The AMP1A-LP and AMP1A-LP2S models include front panel dual 10-segment tri-color LED bargraph level meters and
Wohlers' proprietary three-LED stereo phase indication feature.

• 98 dB SPL at two feet

• Only one rack space high

• Excellent high frequency response for positive detection of

background whine and noise

• Audible indication of phase/polarity problems

• Thorough magnetic shielding for placement next to video

monitors

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© 2006 Wohler Technologies Inc. ALL rights reserved

Features

• Numerous control and input options

• Quick and easy installation: simply slide in the rack and connect
audio and AC power

• LP models offer dual level meters and stereo phase indication
LEDs

• 2S models offer front panel switching between two stereo
inputs

AMP1A/-2S/-LP/-LP2S User Manual, P/N 821526, Rev-D

Section 1: General Features and Specifications

Applications

The AMP1A Series is ideally suited for use in VTR bays, mobile production vehicles, teleconferencing installations, multimedia systems,
satellite links and cable TV facilities, and on-air radio studios. Designed and manufactured in the U.S., the AMP1A Series is backed by a
strong warranty and a satisfaction guaranteed return policy.

General Specifications

Input impedance:

Input Level for Maximum
Output (Volume Full On):

Input Overload:

Peak Acoustic Output
(@ 2 ft.):

Response, Sixth Octave:

Power output

RMS Each Side:
RMS Bass:

Distortion, Electrical:

Distortion, Acoustic:

Hum and Noise:

Magnetic Shielding:

Input Connectors:

Power Consumption
(Average Maximum):

AC Mains input:

Medium-size SegmentsMedium-size Segments

Medium-size Segments

Medium-size SegmentsMedium-size Segments

(f(f

or Midor Mid

(f

or Mid

(f(f

or Midor Mid

dledle

-distance-distance

dle

-distance

dledle

-distance-distance

200K Ω (Ohm) balanced
40K Ω (Ohm) unbalanced, minimum

0 dBv balanced

-10 dB unbalanced

+26 dBv balanced
+14 dBv unbalanced

98 dB SPL

80 Hz - 16 kHz ± 7 dB)
(-10 dB @ 50 Hz, 22 kHZ)

10 W transient / 5 W continuous
20 W transient / 10 W continuous

Less than 0.15% at any level below
limit threshold

8% or less at worst case frequencies
above 180 Hz including cabinet
resonance; typically less than 2%

Better than -68 dB below full output

VV

ieie

wingwing

V

ie

wing

VV

ieie

Less than 1 Gauss any adjacent
surface

Balanced: XLR
Unbalanced: RCA phono

35 W

100-240VAC, 50-60 Hz

wingwing

Level Meter Specifications (-LP)

Level Calibration:

Frequency Response:

Level Meter Type:

LED Color:

Metering Range:

Display Modes:

VU Characteristics,

Rise Time:
Decay Time:

PPM Characteristics,

Attack Time:
Decay Time:

-6, 0, +4, +8 dBv

20 Hz to 18 kHz (±0.5 dB)

10-segment tri-color LED bargraph
display

Tricolor (red, amber, green)

23 dB

VU or PPM, Selectable

300 ms to 99% of full indication
300 ms

10 ms
2 seconds, 0 to -20 dB

Physical Specifications

Dimension (h x w x d):

Weight:

1.75 x 19 x 12 inches

44.5x 483 x 298 mm

14 lbs. (6.4 kg)

Audio Response

+10

0

d
B

-10

-20

-30

Typical 1/6 Octave Audio Response Curve

Hz

10k5k2k1k50020010050 20k20

Wohler Technologies offers by far the broadest range of standard production audio monitor units. Standard-production models or
special order custom features for the AMP1A Series (1U) units include the following functions (and combinations thereof):

• Multiple stereo input selection, from 2 to 10

• AES/EBU and SDI (SMPTE259) inputs

• Separate channel volume controls

• Mono, mute, and mode switches

• Alternate level meter scales and color maps

Other custom options are possible. Call your dealer or Wohler Technologies to discuss your specific needs.

Units are designed to meet, at time of manufacture, all currently applicable product safety and EMC requirements, such as those of CE. 0
dbV ref. 0.775V RMS. Features and specifications subject to improvement without notice.

© 2006 Wohler Technologies Inc. ALL rights reserved

Other Options

• High resolution 26-segment bargraph level meters

• Transformer coupled inputs

• FULL output power DC operation

• External speaker capability

• Multiple input and output connector type choices

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AMP1A/-2S/-LP/-LP2S User Manual, P/N 821526, Rev-D Section 1: General Features and Specifications

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© 2006 Wohler Technologies Inc. ALL rights reserved

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AMP1A/-2S/-LP/-LP2S User Manual, P/N 821526, Rev-D

Section 2

Operation

Installation

Front Panel Features

Rear Panel Features

© 2006 Wohler Technologies Inc. ALL rights reserved

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