RJM ADA-101 User Manual

ADA-101

Analog Audio

Distribution Amplifier

RJM & Associates, LLC

175 Joerschke Drive, Suite A

Grass Valley, CA 95945

Phone: [phone] Fax: [phone]

info@rjmandassociates

www.rjmandassociates.com

Statement of Warranty

Statement of Warranty

Statement of WarrantyStatement of Warranty

RJM & Associates, LLC warrants its products for a period of three (3) years from
the date of shipment to be free from defects in materials and workmanship and
meets applicable published specifications. Equipment which has been operated
within its ratings and has not been subjected to mechanical or other abuse or
modification by the purchaser, its agents, and/or employees, will, at the option of
RJM, be replaced or repaired if it is returned, freight prepaid, to RJM &
Associates, LLC. Equipment that fails under conditions other than described
herein will be repaired at the price of components and labor in affect at the time
of repair.

This warranty is in lieu of all other warranties, expressed or implied, with respect
to the condition or performance of any RJM product, its merchantability or fitness
for a particular purpose. RJM is not liable for any consequential damages.

FCC Compliance

FCC Compliance

FCC ComplianceFCC Compliance

This equipment has been tested and found to comply with the limits for a Class A
digital device pursuant to Part 15 of the FCC Rules. These limits are designed to
provide reasonable protection against harmful interference when the equipment
is operated in a commercial environment. This equipment generates, uses, and
can radiate radio frequency energy and, if not installed and used in accordance
with the instruction manual, may cause harmful interference to radio
communications. Operation of this equipment in a residential area is likely to
cause harmful interference in which case the user will be required to correct the
interference at his own expense.

Copyright

Copyright

CopyrightCopyright

© 2014 RJM & Associates, LLC

Contents of this publication may not be reproduced in any form without the
written permission of RJM. Reproduction or reverse engineering of copyrighted
software is prohibited.

July 2014
Part Number 71

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0022224444

7171

0000

Table of Contents

Table of Contents

Table of ContentsTable of Contents

Section I

Section I

Section ISection I

General Description ................................................................................................ 1

Section II

Section II

Section IISection II

Specifications .......................................................................................................... 2

Section III

Section III

Section IIISection III

Installation ............................................................................................................... 3

Section IV

Section IV

Section IVSection IV

Circuit Description ................................................................................................... 4

Section V

Section V

Section VSection V

Diagrams ................................................................................................................. 5

Module Schematics ........................................................................................... 6

SECTION I

SECTION I

SECTION ISECTION I

General Description

General Description

General DescriptionGeneral Description

ADA

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ADAADA

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The ADA-101 is a modular, high performance audio distribution amplifier
intended for studio quality audio distribution systems. It is designed to be
operated from the RJM AMF-100 mounting frame, or it is pin-compatible with the
Leitch* FR-883/884 audio mounting frames.

The module can be configured as a one-input by eight-output monaural, or as
two, one-input by four-output stereo amplifiers, just by moving one internal
jumper. In the MONO mode only the

Channel B

input is left unconnected.

Channel A

input connector is used. The

All inputs can be connected balanced or unbalanced. Outputs are always
balanced. Both preset and variable gain controls are available which will provide
a gain range of -6 to +33dB.

Each module has its own on-board voltage regulators with fuse protection. Any
failure of a single module will not affect any other.

*Leitch is a trademark of Leitch Technology International, Inc.

SECTION II

Maximum level

Common Mode Rejection, (CMRR)

Common Mode Range

Outputs per channel

Maximum Level

Frequency Response

Total Harmonic Distortion, (THD)

Intermodulation Distortion, (IMD)

Isolation between Modules

Interchannel Crosstalk

Power Dissipation

SECTION II

SECTION IISECTION II

Specifications

Specifications

SpecificationsSpecifications

ADA

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ADAADA

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Input:

Input:

Input:Input:

Number 2, Channel A and Channel B, (Channel A

used for mono)
Type Differential
Impedance

Outputs:

Outputs:

Outputs: Outputs:

Channels 1 (mono) or 2 (stereo)

8 balanced monaural
Impedance

Performance:

Performance:

Performance:Performance:
(each channel)

Gain range

* Specifications and design are subject to change without notice.

>30KΩ balanced, >12KΩ unbalanced

+30dBu (66Ω), +24dBm (600Ω)

>90dB @60Hz, >60dB @20KHz

±20volts

4 balanced stereo

66Ω balanced or 600Ω balanced

+30dBu (66Ω), balanced

+24dBm (600Ω), balanced

-6dB to +33dB (± 6dB with pot, and

0, +9, +18, +27dB with jumpers)

±0.05dB, 20Hz to 20KHz, ref. 1KHz any

level up to +30dBu (66Ω),

+24dBm (600Ω)

<0.05%, 20Hz to 20KHz @ 30dBu,

+24dBm (600Ω)

<0.02% 4:1 SMPTE @18dBu (66Ω),

+18dBm (600Ω)

>100dB, 20Hz – 20KHz

>95dB, 20Hz – 20KHz

<2W

2

SECTION III

SECTION III

SECTION IIISECTION III

Installation and Operation

Installation and Operation

Installation and Operation Installation and Operation

The ADA-101 audio distribution amplifier is designed to be mounted in either the
RJM AMF-100 audio mounting frame, (up to twelve modules), or a Leitch* audio
frame (such as the FR-883 or FR-884). There are no special cooling
requirements, although care should be taken to ensure that extremely hot
equipment is not installed directly beneath the frame.

It is recommended that when redundant power supplies are included in the
frame, the two power cords be connected to different AC supplies. In this way the
frame will continue to operate even if there is a partial failure of plant power.

Before installing the module in the frame, it is necessary to set the internal
jumpers to the desired mode. Jumper H2 selects either MONO or STEREO
mode, and jumpers H1 and H3 set the desired gain of each channel.

The frame input and output connections are similar for both the RJM and the
Leitch* frames. They consist of three-pin terminal blocks as defined below:

CH A

CH A CH B

CH ACH A

CH B

CH BCH B

ADA

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INPUTS

J2 J1

J4 J3

OUTPUTS -

-

S

+

S S

+

+

S

-

+

-

3

SECTION IV

SECTION IV

SECTION IVSECTION IV

Circuit Description

Circuit Description

Circuit DescriptionCircuit Description

The ADA-101 consists of two identical input circuits and two identical groups of
four output circuits. A jumper (H2) permits the two output channels to be both
connected to one input channel for use as a one input, eight output monaural
amplifier or a two channel, four output stereo amplifier. Since both input
amplifiers are the same only the A channel will be described.

The differential input signal is applied to the inverting inputs of U3:A and U3:B.
An inverted version of the common mode signal (if any) is also applied to these
inputs from U6:A such as to cancel any common mode component at the outputs
of U3:A and U3:B. The outputs from U3:A and U3:B are then applied to the
differential amplifier, U6:B. Optimum common mode balance is achieved by
adjusting RV3 at the output of U6:A.

The output from the differential amplifier passes via the gain control
potentiometer, RV1, to the programmable gain amplifier, U5:A. This amplifier
provides fixed gains of 0dB, +9dB, +18dB and +27dB. The desired gain is set by
H1.

The output from U5:A is connected to the first group of four output amplifiers and
also to the MONO/STEREO selector, H2. U4:A provides the un-inverted signal to
the non-inverting output drivers, while U4:B provides an inverted signal to the
inverted output drivers. The A channel drivers are contained in U1 and U8 while
the B channel drivers are contained in U2 and U9. U4:C and U4:D provide the
input to the B channel output drivers.

The input and gain stages are powered from ±15V supplies provided by VR1 and
VR2.

The output drivers are powered directly from the ±21V supplies.

ADA

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4

SECTION V

SECTION V

SECTION VSECTION V

ADA

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Diagrams

Diagrams

DiagramsDiagrams

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ADA-101 AUDIO DISTRIBUTION AMPLIFIER

PS-102 AUDIO POWER SUPPLY

ADA-101 PIN ASSIGNMENTS

5

PIN ASSIGNMENTS

PIN ASSIGNMENTS

PIN ASSIGNMENTSPIN ASSIGNMENTS

Audio Distribution Amplifier

Audio Distribution Amplifier

Audio Distribution AmplifierAudio Distribution Amplifier

INPUT A -…..A 1....INPUT A+

OUTPUT 1 -…..B 2…..OUTPUT 1+

OUTPUT 2 -…..C 3....OUTPUT 2+

OUTPUT 3 -…..D 4....OUTPUT 3+

OUTPUT 4 -…..E 5....OUTPUT 4+

INPUT B -…...F 6....INPUT B+

OUTPUT 5 -…..G 7....OUTPUT 5+

OUTPUT 6 -…..J 10...OUTPUT 7+

GND…...K 11...+21 VOLTS

OUTPUT 7 -…..L 12...OUTPUT 8+

N.C…..M 13...-21 VOLTS

OUTPUT 8 -…..N 14...N.C.

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ADAADA

N.C…..H 8....OUTPUT 6+

N.C.…..I 9....GND

N.C…. O 15...GND

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6