AIR corp

PRO ANNOUNCER MODEL 500 PH

SPEECH PROCESSOR

REVISION G

REFERENCE AND OPERATOR'S MANUAL

ADVANCED INSTRUMENT RESEARCH

CORPORATION

1845 West Hovey AvenueNormal, IL 61761-4315 USA

Phone (309) 454-4900 - Fax (309) 452-0893

iModel 500 PH 07/08/94 - AMR

TABLE OF CONTENTS

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

THEORY OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

FRONT, REAR & TOP CHASSIS DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

FRONT PANEL CONTROLS AND FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

REAR PANEL CONTROLS AND FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8EQUALIZER ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

LOW FREQUENCY SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8MID-RANGE FREQUENCY SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8HIGH FREQUENCY SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

COMPRESSOR GAIN CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8EXPANDER RANGE CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8TYPICAL SET-UP AND OPERATION PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . 9

POWER-ON DEFAULTS, SETTING SW 101 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

MULTIPLE MICROPHONES / MULTIPLE PROCESSORSUSING DYNAMIC CONTROL COUPLING . . . . . . . . . . . . . . 10

SYMMETRY CORRECTION, ENABLING/DISABLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

EXTERNAL CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11AUDIO CONNECTOR XLR PIN-OUTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11SEND & RETURN 1/4 INCH TRS JACKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11INPUT & OUTPUT CONNECTORS FOR UNBALANCED APPLICATIONS . . . . . . 12DYNAMIC CONTROL COUPLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13REMOTE CONTROL CONNECTOR DB-25F PIN-OUTS . . . . . . . . . . . . . . . . . . . . 13

WARRANTY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15OUTPUTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15LINE SEND/RETURN EFFECTS LOOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16DYNAMIC RANGE PROCESSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16EQUALIZER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17ELECTRICAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17MECHANICAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17SPECIFICATION NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

TABLE OF CONTENTS, CONTINUED

iiModel 500 PH 07/08/94 - AMR

BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

PHONE JACK ASSEMBLY DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

FRONT PANEL & MAIN PRINTED CIRCUIT BOARD DIAGRAMS . . . . . . . . . . . . . . . . . . 21TOP VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21BOTTOM VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

SCHEMATIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23AUDIO PATH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24LOGIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25FRONT PANEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26POWER SUPPLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27POWER MODULE, RFI BOARD, POWER TRANSFORMER . . . . . . . . . . . . . . . . . 28

PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29FRONT PANEL PC BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29MAIN PC BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30MAIN PC BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31MAIN PC BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32CHASSIS MOUNTED ELECTRONIC COMPONENTS . . . . . . . . . . . . . . . . . . . . . . 33

1Model 500 PH 07/08/94 - AMR

INTRODUCTION

Advanced Instrument Research Corporation, or AIR corp, was established by broadcastconsultant, James P. Loupas, and electronics designer and technical consultant, MichaelMorgan, ScD.

The Pro Announcer Model 500 PH Speech Processor was designed in Nashville,Tennessee, a world-famous center for the music industry and the recording arts, providing

AIR corp access to some of the best minds (and ears) in the industry. No product passes

AIR corp's stringent development process without coming under the scrutiny of some of the

industry's toughest customers... and at AIR corp, we listen to them, frequently incorporatingtheir suggestions in the final product.

Through use of appropriate technology and economy of design, AIR corp products areintended to solve problems which are present in specific applications, such as treatment ofspoken word prior to transcription or broadcast. We strive to make operation of ourequipment easy and intuitive, and assemble each unit with care and pride, and withserviceability in mind.

Your AIR corp Pro Announcer Model 500 PH has several unique features which enhancedependability and serviceability. Among them are:

* A durable Lexan® graphics front overlay which will withstand years of use withoutlosing legibility,

* Two integrated printed circuit boards interconnected by a single ribbon cable,

* An RFI protected and internationally convertible power supply system,

* A heavy-duty steel and aluminum housing, with replaceable rack-mounting handles,

* A well-ventilated chassis which permits units to be stacked.

Except for the circuit boards themselves, there are few "proprietary" components which must

be ordered from AIR corp in the event of failure.

Technical assistance (warranty, repair, etc.) is available by calling (309) 454-4900 during ournormal business hours (8:00 am to 4:30 pm Central Time) or by submitting a request viaFAX to (309) 452-0893.

Thank you for choosing the Pro Announcer Model 500 PH for your speech processingneeds.

2Model 500 PH 07/08/94 - AMR

DESCRIPTION

The AIR corp Pro Announcer Model 500 PH is a dedicated Speech Processor for Radio on-

air use. The Model 500 PH incorporates the functions of a wide-range, low-distortion, low-noise input; a three-band boost and cut equalizer section; a symmetry correction (all-passfilter) network for waveform symmetry correction; and a compressor with interactiveexpander and gate plus a side-chain sibilance control network (de-esser). Each of thesefunctions exhibits certain parameters, such as frequency breakpoints, ratio and slope, andprocessor time constants, which are selected for best control and enhancement of spokenwords.

There are many unique and useful features which separate the Model 500 PH from older,

less versatile "microphone processors." The Model 500 PH can accept inputs at anynormally encountered level, from microphone feeds at 1 mV or less to line feeds up to +26db. Inclusion of the "symmetry correction" circuitry allows higher average output powerlevels for the processed speech prior to clipping than a simple peak limiter or compressorcan provide. The expander circuitry is designed specifically for spoken word, and is fullyinteractive with the compressor to eliminate noise trailing.

A complete complement of remote functions is available through the rear-panel DB-25connector, allowing the operator to monitor and change the status of the logic functions ofthe device, thus enabling the instantaneous change of input level ranges, send/insert circuit,

sibilance control (de-esser) circuitry, and monitoring point of the vu meter. Finally, the Model

500 PH has both line-level and microphone-level outputs available for connection to externalfeeds.

The AIR corp Model 500 PH incorporates those functions which the Radio SoundProfessional finds most necessary and useful in the processing of spoken word, withoutadding obscure functions and controls of little use.

INSTALLATION

Ideally, we suggest leaving one rack space vacant between units. When this is not possible,

the multi-vent features of the Model 500 will normally provide adequate ventilation.

When multiple units are in a common rack, we recommend using one common power strip(same phase, same 3rd pin ground) to minimize hum and ground loop problems.

The AIR corp Model 500 Input (Microphone In XLR) will accommodate any broadcast levelwith pin #1 grounded on the XLR connector. The Line Out (Line Level Output) XLR has pin#1 grounded. Please note that the Mic. Out (Microphone Level Output) XLR has an ACground (capacitive) on pin #1 assuming that any microphone input that is being fed also haspin #1 grounded. Pin #2 is high and Pin # 3 is low on all input and output XLR connectors.

If a security cover is required, we suggest use of an Orban Model SC1 Security Cover for aSingle Rack Unit. This device can be ordered through most broadcast distributors. To

accommodate the security cover, it is necessary to replace the standard Model 500 rackmounting brackets. (These brackets incorporate protruding handles which interfere with thesecurity cover.) A pair of replacement rack mounting brackets (without handles) is availablefrom AIR corp by ordering part number 382-9104-020.

3Model 500 PH 07/08/94 - AMR

THEORY OF OPERATION

The AIR corp Pro Announcer Model 500 PH incorporates several interactive processing

functions to perform various operations upon spoken word. All of the Model 500 PH'sdynamic functions are the result of interactive analog computers which control a commonVoltage Controlled Amplifier (VCA).

The Model 500 PH Equalizer Sections are peaking "tone control" types, chosen for theirease of operation, relatively wide response, and lack of obvious coloration. In addition, thistype of variable gain filter seems uniquely suited for tailoring microphone sound quality. The

center frequencies for the Model 500 PH equalizer were determined empirically using a widevariety of microphones in a range of live situations. The center frequencies may be alteredby changing capacitor values in the filter sections. Please contact the factory for assistance.

A Symmetry Correction Network follows the equalizer. Symmetry Correction consists of anAll-Pass Filter Network sometimes referred to as a Phase Rotator and is used to correctasymmetry in the electrical waveform as reproduced by a microphone. Asymmetry ischaracteristic of most human voices, and usually causes some difficulty when the intent ofthe processing is to increase the loudness of the on-air personality's voice. Critical listenersmay discern an alteration in "crispness" or "brightness" in the voice when SymmetryCorrection is in the signal path. This is the result of the all-pass filter network, and is anormal side effect of passive symmetry correction. The Equalizer will easily correct this

effect. It may be desirable to disable Symmetry Correction when the Model 500 PH is used

with a lapel microphone. See SYMMETRY CORRECTION, ENABLING/DISABLING forinstructions.

The interactive Compressor/Expander has a fixed compression ratio, fixed expander slope,and fixed, program-dependent attack time for both sections. The compressor and expanderrelease times are program-dependent and complementary to eliminate undesirableprocessing artifacts such as noise rush-up and "pumping" of the signal level. The range ofexpander attenuation, or maximum amount of gain reduction in the absence of spoken word,is adjustable. (Internal controls for compression ratio and release time are factory adjustedand sealed. Field adjustment is not recommended.)

The De-Esser (sibilance control) circuitry is part of the compressor control circuit. The

Model 500 PH De-Esser does not affect the high-frequency content of the processed signal,but rather causes more compressor gain reduction in the presence of high-frequency energy

in the signal. The De-Esser circuitry may be left active under normal conditions.

The Send Switch controls an insert point for an Effects Loop which facilitates the use of anoutboard, line-level device such as a Harmonizer®. This circuit interrupts the normal audiopath, sends the equalized audio signal to the outboard unit, and inserts the audio returningfrom the outboard device into the compressor.

5Model 500 PH 07/08/94 - AMR

FRONT PANEL CONTROLS AND FEATURES(LEFT TO RIGHT)

Please refer to the FRONT, REAR & TOP CHASSIS DIAGRAM for the position of the followingfront panel controls and features.

INPUT Select Switches - Select from four audio level ranges with momentary Up and Downpush-button switches. LED's indicate the selected range: 0 db (+4 dBm nominal), -10 dB,-30 dB, and -50 dB. These ranges satisfy any requirements encountered in today's studioenvironments.

INPUT Adjust Control - Permits approximately ±10 dB of input gain adjustment to theequalizer input.

INPUT CLIP Indicator (Red LED) - Warns of input stage overload.

EQUALIZER Controls - Provide approximately ±20 dB of boost and cut at the followingcenter frequencies:

Low Frequency Approximately 140 Hz

Mid-Range Approximately 2.5 kHz

High Frequency Approximately 5.0 kHz

The shape of the equalizer networks is designed to minimize the buildup of hiss and lowfrequency room noise while maximizing the effect on voices.

EQUALIZER Clip Indicator (Red LED) - Warns of Equalizer overload.

Line Send Switch - Controls an insert point for any line-level device such as a Harmonizer®. The 1/4 inch TRS Line Send Jack on the rear panel sends equalized audio to the outboarddevice, while the 1/4 inch TRS Line Return Jack interrupts the normal audio path and insertsthe output of the outboard device into the compressor. The Send and Return Jacks arebalanced circuits using tip/ring/sleeve (TRS) or "stereo" plugs for external connections. SeeEXTERNAL CONNECTIONS for wiring instructions.

Depressing the Send Switch activates the Line Return switching and inserts the line returnsignal into the audio path.

The "In" (Green) LED above the Send Switch indicates that the Line Send circuit has beenactivated.

COMPRESSOR Gain Control - Allows approximately ±20 dB of level adjustment at thecompressor input thus increasing or decreasing the amount of compression.

DS Switch (De-Esser On/Off) - Activates the de-esser (sibilance control) circuit which is inthe compressor side chain. The de-esser only functions when the "sss" component reachesa pre-set threshold. This circuit contributes no high-end deterioration for normal material.

The "In" (Green) LED above the DS Switch indicates activation of the De-Esser circuit.

6Model 500 PH 07/08/94 - AMR

GAIN REDUCTION Meter Array - Dynamically indicates the amount of gain reduction(compression or downward expansion) being directed to the Voltage Controlled Amplifier(VCA). In addition, it shows the amount of expansion occurring in absence of signal.

The "< Comp." and the "Exp. >" LED's indicate whether the compressor or expander isperforming the gain reduction at any given moment to facilitate adjustment.

EXPANDER Range Control - Adjusts the amount of downward expansion thus controllingambient room noise and reducing circuit noise. No more than 20 dB of expansion isrecommended for normal applications. Adjustment of the expander range control for morethan 30 dB automatically changes the expander into a gate for use in special applications.

vu Meter Array - Displays either Input or Output Level as selected. Input reads the level atthe input of the compressor -- following the Send Circuit. Output reads the level at theoutput of the compressor -- prior to the line driver stage. A meter indication of "0" isequivalent to a +4 dBm (600 ohm) line output. The microphone level output is -50 dB belowthe line level output.

vu Select Switch - Toggles the function of the vu Meter between Input and Output. This

switch is located above the vu Meter Array. The green "< Input" and "Output >" LED's belowthe meter indicate the current function of the vu Meter Array.

OUTPUT Gain Control - Adjusts the operating gain of the VCA (Voltage Controlled Amplifier).

This allows the Model 500 PH output level to be trimmed to match the requirement of thefollowing unit in the audio chain. The Output Gain Control simultaneously adjusts mic., line,and headphone output levels.

Headphones Jack - Provides a buffered output for use with stereo headphones. This

allows adjustment of the Model 500 PH by monitoring the processed signal just beforethe output line-driver stage. This is a 1/4 inch TRS (stereo) headphone jack wired to providea mono signal to stereo headphones.

7Model 500 PH 07/08/94 - AMR

REAR PANEL CONTROLS AND FEATURES(LEFT TO RIGHT)

Please refer to the FRONT, REAR & TOP CHASSIS DIAGRAM for the position of the followingrear panel controls and features.

Power On/Off Switch - Connects the ac mains to the power transformer primary.

Power Entry Module consisting of:

Mains Select Switch - Configures the primary windings of the power transformer foreither 110-120 Vac or 220-240 Vac operation.

Fuse Holder - Accepts 3 AG type 5 X 20 mm fuses. See SPECIFICATIONS,ELECTRICAL for recommended fuse ratings.

Mains Input Connector - Provides the unit with ac power through internationalelectrical appliance cords.

Mic. Out (Microphone Level Output XLR) - Provides 150 ohm balanced output at -50 dBrelative to the line output level as indicated on the vu Meter Array. See EXTERNALCONNECTIONS for pin-out information.

Line Out (Line Level Output XLR) - Provides a low-impedance, servo-balanced, line-driveroutput at the level indicated on the vu Meter Array. See EXTERNAL CONNECTIONS for pin-outs.

Line Return 1/4 inch TRS Jack - Returns audio from the output of an outboard device. SeeEXTERNAL CONNECTIONS for pin-out information.

Line Send 1/4 inch TRS Jack - Sends audio to the input of an outboard device. SeeEXTERNAL CONNECTIONS for pin-outs.

Remote Control Connector - Provides control inputs and indicator outputs via a DB-25F

connector for all of the on-board logic functions of the Model 500 PH, such as Input LevelSelect, Send On/Off, DS On/Off, and vu Meter Input/Output. See EXTERNALCONNECTIONS for pin-out information.

Phantom Power (+48 Vdc) Switch - Applies voltage from the internal +48 Vdc supply to themicrophone input connector for parallel powering of condenser microphones.

Input (Microphone In XLR) - Accepts balanced or unbalanced inputs from microphone levelto line level. See EXTERNAL CONNECTIONS for pin-out information.

8Model 500 PH 07/08/94 - AMR

OPERATING INSTRUCTIONS

Operation of the Model 500 PH is quite simple; and, although the functions of the controlsare mostly self-evident, a quick run-through of each of the adjustable dynamic parameters

and its audible effect is appropriate.

EQUALIZER ADJUSTMENTS

The Model 500 PH equalizer filter characteristics are designed to: permit matching of thelive voice with other program material; give voices a unique sound; and give voices thepower and "edge" required to talk over music. Through proper use of equalization,intelligibility can be improved and a pleasing yet substantial sound can be achieved.

LOW FREQUENCY SECTION The low frequency control, when boosting, has theeffect of adding more richness and bass to a thin or weak vocal announcement. Overuse of the low frequency boost tends to muddle the speech and lowersintelligibility, particularly if the signal is somewhat lacking in high frequencies, as is

the case when the microphone is severely off-axis. When cutting, the low frequencycontrol reduces the muffled sound of some microphones.

MID-RANGE FREQUENCY SECTION The mid-range frequency control, when

boosting, may add some apparent loudness to the voice, but at the expense of

fidelity. Mid-range frequency cutting is necessary with some microphones which areoverly bright in the mid-range.

HIGH FREQUENCY SECTION The high frequency control, when boosting, restores

intelligibility to the performer's voice. When cutting, the high frequency attenuation ishelpful in removing "tinny" sounds. Overuse of high frequency boost results in anobnoxiously bright and thin quality in the voice. Moderate use of a combination ofhigh frequency boost and low frequency boost, however, can add significantly to the"presence" of an announcer's voice.

COMPRESSOR GAIN CONTROL

After proper setup, use of large amounts of compressor gain results in a denser, louder

voice signal. Use of more than 7 to 10 dB of indicated gain reduction during compressionwill create a very "loud" output. Additionally, with larger amounts of compressor gain, theexpander should be used to reduce noise rush-up during compressor release.

EXPANDER RANGE CONTROL

The Expander attenuates noise occurring between utterances of spoken word. TheExpander Range Control interacts with the Compressor to "isolate" the processed signal.

This has the effect of audibly moving the processed voice nearer the listener and

attenuating room noise and reverberations as more range (attenuation occurring betweenutterances) is added. With large amounts of compressor gain, the primary use of theexpander is to avoid noise rush-up during compressor release. In most cases, the ExpanderRange Control should be adjusted to produce the same amount of gain reduction in theExpander Mode as is produced in the Compression Mode.

9Model 500 PH 07/08/94 - AMR

TYPICAL SET-UP AND OPERATION PROCEDURE

After connecting the Model 500 PH to its appropriate source and destination, perform the

following set-up procedure using the on-air talent in a normal announce situation:

Choose the correct INPUT Level Range with the INPUT Select Switches. For mostmicrophones, the -30 dB input range is correct. If the INPUT CLIP Indicator lights at peakaudio levels, then switch up-range (-10, 0, etc.).

Trim the INPUT Level Adjust for a reliable, -15 dB indication on the vu Meter Array whenassigned to INPUT. If you are unable to obtain a nominal -15 dB indication, you may wish toswitch the INPUT Select downrange (-30, -50, etc.).

Set Low, Mid, and High EQUALIZER controls to 0 (12 o'clock position);

Adjust the COMPRESSOR Gain control for 5 to 7 dB of gain reduction on peaks. Later addmore or less gain (compression) to suit. Make sure the "< Comp." LED is illuminated whilemaking this adjustment.

Select DS (De-Esser) if required. The De-Esser (sibilance control) may be left onpermanently without causing problems in most circumstances.

Adjust the OUTPUT Gain as required.

Adjust the Low Frequency EQUALIZER control to eliminate "muffling", or to add bass textureto the voice as required.

Adjust the High Frequency EQUALIZER control to restore normal brightness to theprocessed voice.

Adjust the Mid-Range EQUALIZER control to restore a normal vocal tone. This will help theannouncer talk over music.

Set the EXPANDER Range control with only a "room noise" input (no signal from the on-airtalent) to produce 5 to 7 dB of gain reduction. Make sure the "> Exp." LED is illuminatedwhen making this adjustment. Increasing Expander Range (counter-clockwise rotation ofthe pot) has the effect of moving the on-air personality audibly closer to the listener and/or

attenuating room noise. NOTE: Range settings greater than approximately 20 dB maybecome noticeable and objectionable to the on-air personality, and adjustment of theexpander range control for more than 30 dB automatically changes the expander into a gatefor use in special applications.

While Monitoring the Processed Signal, reset the INPUT Level Adjust, if required, toeliminate choppiness or pumping of the spoken word by the expander.

Guidelines:

* Don't over equalize.

* Avoid over processing.

Microphones act differently when processed. Tonal quality may change drastically whencompression (power) is added.

10Model 500 PH 07/08/94 - AMR

POWER-ON DEFAULTS, SETTING SW 101

The Power-On Default Switches program the flip-flops in the digital control section to

configure the Model 500 PH's logic upon power-up. These DIP switches set the defaultvalues for Audio Input Level, Line Send, De-Esser, and vu Meter function. This feature re-establishes the desired default settings in the event of a momentary power interruption.

To gain access to the Power-On Default Switches, Switch Bank SW 101, remove the topcover by loosening the capture screws and pushing the top cover toward the rear of the unit. This exposes the top of the printed circuit board. SW 101, is the 14-pin DIP package directlybehind the front panel Low and Mid-Frequency Equalizer Controls (pots).

SELECTION SWITCH POSITION X = EITHER POSITION

* FACTORY SETTING 1 2 3 4 5 6 7

0 Input Level ON OFF ON OFF X X X

-10 Input Level OFF ON ON OFF X X X

-30 Input Level * ON OFF OFF ON X X X

-50 Input Level OFF ON OFF ON X X X

Line Send - On X X X X ON X X

Line Send - Off * X X X X OFF X X

De-Esser - On * X X X X X ON X

De-Esser - Off X X X X X OFF X

vu Meter - Input X X X X X X ON

vu Meter - Output * X X X X X X OFF

MULTIPLE MICROPHONES / MULTIPLE PROCESSORS

USING DYNAMIC CONTROL COUPLING

The Model 500 provides the best close-coupled, downward expander performance in theaudio industry - with maximum microphone isolation and minimum unwanted room noise. Occasionally, studio "room geometry" creates very high standing waves and a "comb filtereffect" best characterized as the "hollow room effect". To deal with this condition, AIR corp

provides the Dynamic Control Coupler, a simple, inexpensive technique to virtually eliminatemulti-microphone problems. This can be especially important for news-talk, TV, interviewand morning shows that use multiple microphones.

Implementation: AIR corp recommends use of identical microphones and centrally located

Model 500 processors. Best performance can be expected when all Model 500 units areplugged into a common power strip. Simply add jumpers from unit to unit. (See EXTERNALCONNECTIONS, Dynamic Control Coupling and Remote Control Connector DB-25F Pin-Outs.) This couples the Dynamic Control side-chains thus permitting all units to communicate witheach other.

11Model 500 PH 07/08/94 - AMR

Interconnected Model 500 processors should be identically adjusted with particular attentionto the amount of dynamic compression as indicated on the compression meter. The unit thathas the loudest announcer, thus the greatest amount of compression, will dominate thesystem. This feature, for example, can be used to allow the host to "shout down"participants. If all units are set in this manner, there will be no perceptible side effectsexcept that the "comb filter" effect will be gone.

SYMMETRY CORRECTION, ENABLING/DISABLING

See THEORY OF OPERATION for an explanation of the Symmetry Correction (All-PassFilter) Network. To gain access to the On/Off jumpers, remove the top cover by looseningthe capture screws and pushing the top cover toward the rear of the unit. This exposes thetop of the printed circuit board.

Jumper Blocks, J106 and J107, are located directly behind the front-panel, Low-FrequencyControl (pot). Symmetry Correction is Enabled (In) when the jumper is on J107. The

Factory Setting for the Model 500 PH is Enabled. Symmetry Correction is Disabled (Out)when the jumper is on J106. A Jumper Table is located on the front edge of the mainprinted circuit board.

EXTERNAL CONNECTIONS

AUDIO CONNECTOR XLR PIN-OUTS

All 3-pin XLR connectors on the AIR corp Model 500 are in accordance with the ANSIStandard S4.48-1992. Mating XLR connectors should be wired as follows:

PIN CONNECTION

1 Screen or Shield (0 Vdc)

2 Positive Polarity

3 Negative Polarity

LINE SEND & RETURN 1/4 INCH TRS JACKS

The Line Send and Return Jacks on the Model 500 PH are balanced circuits using 1/4 inchTRS (Tip/Ring/Sleeve) or "stereo" plugs for external connections.

If a balanced outboard device is to be used, the external TRS phone plugs should be wiredas follows:

PIN CONNECTION

Tip Positive Polarity

Ring Negative Polarity

Sleeve Screen or Shield (0 Vdc)

If an unbalanced outboard device is to be used, wire the TRS plugs in such a manner as to

12Model 500 PH 07/08/94 - AMR

unbalance the audio signal at its source using a two conductor cable with a shield. Pleaseobserve the following detailed instructions:

If feeding the unbalanced input of an outboard device from the Model 500 PH LineSend Output (source), connect the 1/4 inch TRS plug so that the tip carries the audio

signal (positive polarity). Unbalance the audio signal at the Model 500 PH Line SendOutput (source) by shorting the ring to the sleeve and connecting both the secondconductor and the shield to the sleeve connection in the source plug. You may wishto leave the shield disconnected (floating) at the input of the outboard device.

When feeding the Model 500 PH Line Return from an unbalanced outboard device(source), connect the audio signal (positive polarity) to the tip of the 1/4 inch TRS

plug used to connect the Model 500 PH. Unbalance the audio signal at the output ofthe outboard device (source) by connecting both the second conductor and shield tothe common ground point at the outboard device. Connect the second conductor(wire coming from the source's common ground point) to the ring of the 1/4 inch TRS

plug used to connect the Model 500 PH. You wish to float the shield by not

connecting the shield to the sleeve in the 1/4 inch TRS plug used to feed the Model

500 PH Line Return from an unbalanced source.

INPUT & OUTPUT CONNECTORS FOR UNBALANCED APPLICATIONS

We recommend connecting the microphone directly to the Model 500 and feeding themicrophone level output to the console microphone input. Should you choose to connect the

microphone to the console and insert the Model 500 into the console unbalanced patchpoints, the following should be observed carefully.

Typical Unbalanced Source Model 500 Mic Input (Console Patch Point) (XLR Input Connector)

Hi Pin 2

Lo Pin 3

These unbalanced connections are best performed in close proximity to the unbalancedsources when the devices share the same 115/230 Vac Phase and Common Ground.

Typical Unbalanced Input Model 500 Line Output(Console Patch Point Return) (XLR Output Connector)

Hi Pin 2

Lo Pin 3

Note: In the Model 500, the Output Pin 3 may be grounded to accomplish this task with nofear of damaging components.

13Model 500 PH 07/08/94 - AMR

DYNAMIC CONTROL COUPLING

Both the Dynamic Control Coupling terminal (pin 25) and Logic Ground terminal (pin 12, 13,

or 14) must be interconnected with the corresponding terminals on all AIR corp Model 500

units that are to be control coupled. See EXTERNAL CONNECTIONS, Remote ControlConnector DB-25F Pin-Outs.

REMOTE CONTROL CONNECTOR DB-25F PIN-OUTS

The remote connector on the Model 500 PH features comparator outputs and Schmitt triggerinputs. All functions are stated relative to Logic Ground at pins 12, 13, and 14.

PIN FUNCTION ACTION

1 0 Input Level LED Sink Goes to -14 V when "on"

2 -10 Input Level LED Sink Goes to -14 V when "on"

3 -30 Input Level LED Sink Goes to -14 V when "on"

4 -50 Input Level LED Sink Goes to -14 V when "on"

5 Line Send "On" LED Sink Goes to -14 V when "on"

6 De-Esser "On" LED Sink Goes to -14 V when "on"

7 Input Level - Toggle Up Take momentarily to Logic Ground

8 Input Level - Toggle Down Take momentarily to Logic Ground

9 Line Send - Toggle On/Off Take momentarily to Logic Ground

10 De-Esser - Toggle On/Off Take momentarily to Logic Ground

11 vu Meter - Toggle Input/Output Take momentarily to Logic Ground

12, 13, 14 Logic Ground * Logic Ground

15 Logic +14 Vdc Powers Remote LED Indicators

16 Logic -14 Vdc Available for external relays, etc.

25 Dynamic Control Coupling * Interconnects units for multi-microphone

applications. *

* Both the Dynamic Control Coupling terminal and the Logic Ground terminal must be

interconnected with the corresponding terminals on the various Model 500 PH Pro

Announcers.

14Model 500 PH 07/20/92 - AMR

WARRANTY INFORMATION

AIR corp warrants its products to be free from defects in workmanship for a period of oneyear after purchase.

Should an AIR corp product fail during the warranty period, return the unit to the dealer from

which it was originally purchased, or ship the unit, along with proof of purchase date, to AIR

corp.

AIR corp will repair or replace the unit at its sole discretion.

AIR corp's warranty will not be voided if the user modifies an AIR corp product using

generally accepted technical procedures, however, broken wire, broken PC board circuit

traces, burned areas and broken components resulting from improper procedures are not

covered under warranty. Charges for non-warranty repairs or customer-requested

modifications will be billed at the current hourly bench rate. Contact the factory for details.

AIR corp's liability is limited to repair or replacement of its product. AIR corp is not

responsible for damages resulting from the use of its product, from incorrect or unsafe

installation, or for damages to equipment caused by war, fire, flood or other man-made or

natural calamities.

15Model 500 PH 02/09/95 - JCF

SPECIFICATIONS, MODEL 500 PH

INPUT

Input type Differentially Balanced, Transfomerless Low-Noise

Amplifier

Input connector 3-pin XLR female

Input impedance 13.6 kOhm with Phantom Power "On"20 kOhm with Phantom Power "Off"

Input CMRR >40 dB (50 Hz-20 kHz)

EIN @ 50 dB gain -127 dB typical with 150 Ohm source

Input level range Nominally, -50 to +4 dB, selectable in four steps

Input adjustment range ±10 dB from indicated input level

Maximum input level +26 dB Ref .775 Vrms (15.5 Vrms)

OUTPUTS

Output type Servo-Balanced, Transformerless Line-Driver Output

plus a Resistive Balanced Attenuator for Microphone

Level Output

Output connectors 3-pin XLR male

Microphone output impedance 150 Ohm ± 10%

Microphone output level -50 dB referenced to 0 vu, nominal-30 dB, maximum

Line output impedance 100 Ohm balanced, 50 Ohm unbalanced

Line output level +4 dBm into 600 Ohms, nominal+26 dBm into 600 Ohms, maximum

Line output residual noise and hum -80 dB Ref .775 Vrms typical (20 Hz to 20 kHz)

Usable dynamic range >100 dB

Quiescent distortion .02% THD @ 1 kHz, typical @ unity gain .05% SMPTE IMD, typical

SPECIFICATIONS, MODEL 500 PH, CONTINUED

16Model 500 PH 02/09/95 - JCF

LINE SEND/RETURN EFFECTS LOOP

Output Type Servo-Balanced, Transformerless Line Driver

Output Connector 1/4 inch TRS (Tip/Ring/Sleeve) Jack

Output Source Impedance 100 Ohm Balanced, 50 Ohm Unbalanced

Maximum Output Level +24 dBm into 600 ohms

Input Type Balanced, Differential, Ground-Sensing Op-Amp

Input Connector 1/4 inch TRS (Tip/Ring/Sleeve) Jack

Input Impedance 100 kOhm Balanced, 50 kOhm Unbalanced

Maximum Input Level +24 dB Ref .775 Vrms (12.2 Vrms)

DYNAMIC RANGE PROCESSOR

Processor Type Feedforward Compressor with interactive expander

and side-chain equalized de-esser

Compressor attack time 10 ms typical, program dependent

Compression ratio Nominally 4:1

Compressor release time 20 dB/second typical, program dependent

Compressor threshold -10 vu, nominally -6 dB Ref .775 Vrms

Expander attack time 10 ms typical, program dependent

Expander slope 1:2 at Range Setting greater than 30 dB2:3 at Range Setting less than 30 dB

Expander release time 20 dB/second typical, program dependent (trackscompressor release)

De-esser side-chain breakpoint Typically 2 kHz (75 :s)

SPECIFICATIONS, MODEL 500 PH, CONTINUED

17Model 500 PH 02/09/95 - JCF

EQUALIZER

Equalizer type First-Order Variable Boost and Cut Series

Bandpass Sections with a two-pole, all-pass

follower for reducing waveform asymmetry

Range of boost or cut ±20 dB, typical

Low Frequency Equalizer fc Nominally 140 Hz

Mid-Range Equalizer fc Nominally 2.5 kHz

High Frequency Equalizer fc Nominally 5.0 kHz

ELECTRICAL

Mains input 115/230 Vac 50/60 Hz ±10%

Mains connector IEC appliance input connector per IEC 320RFI protected with printed circuit board LC network

Power consumption 15 VA maximum

Fuse rating Use a 5 X 20 mm fuse of the type specified below:

115 Vac 50 & 60 Hz - GDA 1/4 Amp Fast-Acting

230 Vac 50 & 60 Hz - GDC 1/16 Amp Time-Lag

- WARNING - Replace Fuse with Same TYPE and RATING Only.

Power Transformer Designed and certified to meet VDE & IEC safetyrequirements

Phantom (parallel) micro- phone power supply output Nominally +48 Vdc @ 6 mA dc characteristics

MECHANICAL

The Model 500 PH is housed in a steel enclosure. A rack mounting kit is included forinstallation into standard, 19" equipment racks.

Dimensions 1.75 Inches High, 16.75 Inches Wide, 8.25 Inches Deep(4.45 cm High x 42.55 cm Wide x 20.95 cm Deep)

Shipping Weight Approximately 9 Pounds (4.08 kg)

SPECIFICATIONS, MODEL 500 PH, CONTINUED

18Model 500 PH 07/08/94 - AMR

SPECIFICATION NOTES

0 dB and 0 dB Ref .775 Vrms refers to O vu at 0.775 Volts rms.

0 dBm refers to 0 vu at a power level of 1 mW into 600 Ohms.

Noise measurements are made using an rms-responding meter in a 20 kHz corrected noisebandwidth.

CMRR = Common Mode Rejection Ratio

EIN = Equivalent Input Noise

Specifications are subject to change without notice.

© Copyright 1994

Advanced Instrument Research

Corporation

All Rights Reserved