background image

© 2004   Wohler Technologies  Inc.   ALL rights reserved

6

AMP2-DA/AVU

 and 

AMP2-DA/APP

 User Manual  P/N 

 821584 

 Rev-

A

Installation

Mounting

The unit should be mounted where convenient for operating persons, ideally at approximately ear/eye level for best high frequency
response and visual observation of the level meters. 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 unit is 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

Connection of the audio feeds is straightforward.  Please refer to the system interconnect block diagram on page 

22

 for

clarification of the general signal paths into and out of the unit.

AES/EBU digital inputs are via female BNC connectors and are configured for 75 

 unbalanced connections.  Analog inputs are

via two 3-pin female XLR connectors and are configured for 70K 

 balanced connections.  Care should be exercised to avoid

mismatched cable types and other similar causes of undesired reflections in RF signal systems.  If severe enough, such reflections
can result in corruption of the digital datastream.

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.

Section 1:

 Features, Specs, and Installation

Summary of Contents for AMP2-APP

Page 1: ...r PCB 919117 AES Mute On Error Jumper Location 919117 PCB PPM Meter Specifications and Level Threshold Settings VU Meter Specifications and Level Threshold Adjustment AMP2 DA AVU and AMP2 DA APP Interconnect Block Diagram AMP2 DA AVU and AMP2 DA APP 2U Digital Audio Speaker Monitor With Two Selectable AES Inputs on BNC Two Analog Inputs on XLR Two Selected Analog Stereo Outputs on XLR Two Mechanic...

Page 2: ...eing 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 ...

Page 3: ...nc ALL rights reserved 3 AMP2 DA AVU and AMP2 DA APP User Manual P N 821584 Rev A Sect 1 General Features and Specifications Features Specs and Installation Description Features Applications Specifications Installation Section 1 ...

Page 4: ... may also select between two AES inputs on the rear panel with a front panel toggle switch AES signal status is indicated by a bi color red green LED Wohler Technologies proprietary three LED stereo phase indication feature allows visual monitoring of phase relationships of the signals assigned to the left and right speaker channels Other features include volume and balance controls power indicati...

Page 5: ...trical Distortion Acoustic Input Overload ConvertedAnalogOutS N ConvertedAnalogOutTHD MagneticShielding PowerConsumption AverageMaximum AC Mains Input AES BNC Analog XLR XLR 70K Ω balanced BNC 75 Ω unbalanced 104 dB SPL 14 W transient 10 W continuous 35 W transient 25 W continuous 80 Hz 16 kHz 5 dB 10 dB 40 Hz 20 kHZ 0 dBv balanced 10 dB unbalanced Better than 68 dB below full output Less than 0 1...

Page 6: ...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 Connection of the audio feeds is straightforward Pleas...

Page 7: ...gies Inc ALL rights reserved 7 AMP2 DA AVU and AMP2 DA APP User Manual P N 821584 Rev A Operation Front Panel Features Rear Panel Features Audio Amplifier and Speaker Configuration Balance Control Characteristics Section 2 ...

Page 8: ...he unit will monitor the AES signals as input on the selected 1 or 2 rear panel AES EBU IN BNC connector Item C page 12 AES Source Select Switch 1 or 2 This two position toggle switch allows the operator to choose between the two rear panel AES EBU IN digital input connectors 1 or 2 Item C page 12 Note that in order to monitor the selected AES input the Analog Digital Source Select Switch Item 3 m...

Page 9: ... 2004 Wohler Technologies Inc ALL rights reserved 9 AMP2 DA AVU and AMP2 DA APP User Manual P N 821584 Rev A Section 2 Operation Figure 2a Front Panel Features ...

Page 10: ...or out of phase signals The large AVG LED indicates the average phase condition by glowing GREEN for in phase signals or RED for out of phase signals In general observing the AVG LED alone is sufficient for proper phase monitoring While it is normal for stereo signals to contain some intermittant instantaneous out of phase and in phase conditions FAST LEDs a steady RED glow of the AVG LED indicate...

Page 11: ... 2004 Wohler Technologies Inc ALL rights reserved 11 AMP2 DA AVU and AMP2 DA APP User Manual P N 821584 Rev A Section 2 Operation Figure 2a Front Panel Features ...

Page 12: ... used AES Input Termination In the event that either of the two AES input channels is fed to downstream equipment the associated DIP switch section section 1 IN 1 and section 3 IN 2 must be placed in the UP Unterminated position If there is no downstream equipment connected then the associated DIP switch section must be placed in the DOWN Terminated position See below left for a diagram of termina...

Page 13: ... 2004 Wohler Technologies Inc ALL rights reserved 13 AMP2 DA AVU and AMP2 DA APP User Manual P N 821584 Rev A Section 2 Operation Figure 2b Rear Panel Features ...

Page 14: ...for low impedance connections and the output signals are not affected by the volume balance controls or headphone mute For XLR pinout information see the diagram below Analog Input Connectors LEFT A and RIGHT B These two 3 pin female XLR connectors Left and Right accept standard analog audio signals and are configured for balanced 70K Ω connections For XLR connector pin out information see the dia...

Page 15: ... 2004 Wohler Technologies Inc ALL rights reserved 15 AMP2 DA AVU and AMP2 DA APP User Manual P N 821584 Rev A Section 2 Operation Figure 2b Rear Panel Features ...

Page 16: ...tics The balance control attenuates the signal from the source so that the left and right bass frequencies summed together and reproduced in the woofer channel will also respond to the balance control Example If an audio signal of a voice speaking English is fed to the left A input and a voice speaking Spanish is fed to the right B input then the left speaker channel will reproduce the midrange an...

Page 17: ...ical Information General Technical Observations AES to Analog Converter Module PCB 919117 AES Mute On Error Jumper Location 919117 PPM Level Meter Specifications and Level Threshold Settings VU Level Meter Specifications and Level Threshold Adjustment AMP2 DA AVU and AMP2 DA APP Interconnect Block Diagram Section 3 ...

Page 18: ... input stage and before the volume control section The signal pick off for the headphones is after the volume and balance controls Speaker muting is controlled by circuitry that senses connection of headphones to the jack The power amps are attached to an aluminum heatsink plate which is also connected to the circuit common for these devices The heatsink plate forms an operational module separate ...

Page 19: ...a 20 bit two channel D to A converter IC10 where the datastream is converted into left and right analog outputs Analog buffer IC4 Output Amplifiers IC8 IC9 Buffer amps provide balanced left and right channel outputs as well as single ended outputs Gain calibration the analog level which corresponds to a given digital value is settable via a DIP switch The default factory setting is 20 dB below ful...

Page 20: ...n Error Jumper Location 919117 Section3 TechnicalInformationMute On Installing a jumper at H12 will mute the audio if errors are detected See page 14 for more information Installing a jumper at H12 will mute the audio if errors are detected See Item 5 page 8 for more information AES to Analog Converter Module PCB 919117 ...

Page 21: ...vel Threshold Settings LevelMeterType LevelMeterScale LevelMeterThreshold LevelMeterDynamics Mechanical StandardVU 0 to 8 dBv factory set to 4 dBv trimpot adjustable internal VU fullANSI LevelMeterType LevelMeterScale LevelMeterThreshold LevelMeterDynamics Mechanical Specify BBC 1 to 7 or EBU type 1 and 2 specified when ordered 6 0 4 or 8 dBv DIP switch selectable internal PPM Level Gain Calibrati...

Page 22: ... 2004 Wohler Technologies Inc ALL rights reserved 22 AMP2 DA AVU and AMP2 DA APP User Manual P N 821584 Rev A AMP2 DA AVU and AMP2 DA APP Interconnect Block Diagram Section3 TechnicalInformation ...

Page 23: ... documentation is available upon request Wohler Technologies Inc 713 Grandview Drive South San Francisco CA 94080 650 589 5676 Fax 650 589 1355 web www wohler com e mail support wohler com Wohler Technologies Inc 31055 Huntwood Avenue Hayward CA 94544 Phone 510 870 0810 Fax 510 870 0811 US Toll Free 1 888 596 4537 www wohler com support wohler com ...

Page 24: ...A Wohler Technologies Inc 713 Grandview Drive South San Francisco CA 94080 650 589 5676 Fax 650 589 1355 web www wohler com e mail support wohler com Wohler Technologies Inc 31055 Huntwood Avenue Hayward CA 94544 Phone 510 870 0810 Fax 510 870 0811 US Toll Free 1 888 596 4537 www wohler com support wohler com ...

Reviews: