Johnson Controls PA0688 Bedienungsanleitung

LT0371 Issue 1.10 7 February 2018 Page 1 of 6

PA0688

Microphone Pre-Amplifier Module

Installation and Operating Instructions

Description

The PA0688 Microphone Pre-amplifier board is intended to provide emergency and non-emergency

microphone pre-amplification to “line” level with or without PTT function.

Overview

The PA0688 Microphone Pre-amplifier Module is designed for use with Vigilant EWIS systems; T-Gen2,

T-GEN 50 and QE90. It contains a microphone pre-amplifier with automatic level control, and two relays

which are operated by the PTT switch on the microphone. Refer to Figure 1.

The first relay switches the line level output between (a) line level input terminals (SPEECH IN) and (b) the

output of the pre-amplifier, and can be used to allow several PA0688 pre-amps to be connected in series to

the same panel input. The second relay is a two-pole changeover relay which can, for example, be used to

disconnect speakers in close proximity to the microphone when the microphone is in use to prevent audio

feedback. It can also be used for various other functions, e.g. to provide a switch input to a QE90 to indicate

that Paging is required.

Audio transformers should be used in conjunction with the PA0688:

for isolation, e.g. where the module is to feed multiple T-GEN units

for balancing, in order to reduce noise pickup in situations where long lines are to be used to feed

unbalanced inputs.

Refer to Figures 2, 6 and 7 for details.

SPEECH OUT

SPEECH IN

Relay Coils

+24V

PTT Switch

PTT Out

MIC IN

SPARE

SPEAKER OUT

SPEAKER IN

Figure 1 - PA0688 Pre-amp Block Diagram

Connection and Operation

QE90

The PA0688 microphone pre-amplifier can be connected to the QE90 in many ways. One example is to

provide local paging to several QE90 amplifiers, using the QE90 amplifier local inputs. Refer to Figure 2.

In Figure 2 there are two pre-amps connected in a daisy chain so that either may be used. In the event of

PTT being pressed on both at the same time, the one closest to the QE90 will have priority. The connection

to the QE90 amplifier local inputs has been isolated by a transformer as these inputs are unbalanced and the

use of the transformer will provide a reduction in hum and noise. The SPKR IN+ and SPARE+ terminals on

the PA0688 have been used to obtain clean contacts which close when PTT is operated, and these have

been wired to a GP or FIP input on the QE90 that has been programmed by the manufacturer to disable

background music to the relevant amplifiers when the local paging is in use.

LT0371 Issue 1.10 7 February 2018 Page 2 of 6

All audio cables should be shielded and the shields connected to ground at the QE90.

MIC

PTT

QE90

Amplifier local input

SPEECH OUT

GP or FIP

Input

PA0688 SPKR IN +

SPARE +

SPEECH IN

0V+24V

SUPPLY

600 Ohm Line

Isolating

Transformer

Possible second

amplifier local input

PA0688

0V+24V

SPEECH OUT

SPEECH IN

SPKR IN +

SPARE +

SUPPLY

MIC

PTT

Figure 2 - Using PA0688 Pre-amp with QE90 Local Inputs

Note - An ALIM9706 could be used for the 600 Ohm Isolating Transformer. Refer to Figure 5.

Another example is shown in Figure 3. In this case the output of the pre-amp is connected to the QE90

MUSIC input, with the zones requiring paging field-programmed into the QE90. This example also shows

how the PA0688 can be used to disconnect speakers near the microphone to prevent feedback.

MIC

PTT

QE90

SPEECH OUT

PA0688

+24V

SUPPLY

MUSIC IN

SPEECH IN

SPEAKER

OUTPUT

Speaker

Matching

Transformer

SPKR IN

Speaker Near

Microphone

Other Speakers

SPKR

OUT

Figure 3 - Using PA0688 Pre-amp with QE90 Music Input

NON-EMERGENCY MICROPHONE ON T-Gen2

T-Gen2 EWS has two audio inputs for connecting non-emergency background music sources or paging

facilities. The PA0688 microphone Pre-Amp can be used to boost a remote microphone voltage to feed into

the T-Gen2 Audio Input for remote paging.

The Pre-Amp needs to be located with the microphone and is supplied with 24Vdc power. Figure 4 shows

the wiring arrangement.

LT0371 Issue 1.10 7 February 2018 Page 3 of 6

Note: Screened cable should be used for the audio connections between pre-amp modules and the T-

Gen2, with the screen connected to the 0V input at the T-Gen2. The paging microphone closest to

the T-Gen will have priority if both microphone PTT buttons are pressed at the same time.

The 24V feed for the Pre-Amps should be separately fused so a fault does not remove power to

the T-Gen2.

SPEECH OUT+

SPEECH OUT-

PA0688 MICROPHONE PRE-AMP

SPEECH IN+

SPEECH IN-

SPEAKER OUT+

SPARE+

24V+

PTT-

MIC

SPEECH OUT+

SPEECH OUT-

PA0688 MICROPHONE PRE-AMP

SPEECH IN+

SPEECH IN-

SPEAKER OUT+

SPARE+

24V+

PTT-

MIC

AUD IN+

AUD IN-

T-Gen2

GP IN

+24V

Figure 4 –Microphone Pre-Amp to T-Gen2

T-GEN 50

Output Level

The PA0688 can be used for paging facilities to boost the voltage from a microphone to the T-GEN's music

input.

In standard form, the PA0688’s output does not provide the 2.5-3V RMS signal level required by the Music

Input of T-GEN 50. To solve this, resistor R28 on the PA0688 Microphone Pre-amp should be changed to

10k.

Wiring - Non-Emergency Microphone

One or more PA0688 Microphone Pre-amps can be wired to the T-GEN as in Figure 5.

Screened cable should be used for the audio connections between pre-amp modules and the T-GEN, with

the screen connected to the 0V input (Pin 2) of J9 at the T-GEN. The paging microphone closest to the T-

GEN will have priority if both PTT buttons are pressed at the same time.

PA0688 MICROPHONE PREAMP

MIC

OUT+

IN+

SPEECH OUT+

SPEECH IN +

R28=10k

PA0688 MICROPHONE PREAMP

MIC

OUT+

IN+

PTT-

SPEECH OUT+

SPEECH IN+

R28=10k

MUSIC

+24V

24V POWER

T-GEN

OPTIONAL

(REPEAT FOR FURTHER

MICROPHONES)

+24V

PTT-

Figure 5 - Unbalanced Configuration, PA0688 to T-GEN 50, Non-emergency Microphone

LT0371 Issue 1.10 7 February 2018 Page 4 of 6

If the T-GEN and pre-amp(s) are not mounted close together then to increase immunity to any ambient

electrical noise, it is recommended that screened cable should be used and an ALIM9706 should be located

at the T-GEN input. This is shown in Figure 6.

Note that the segments of screened cable connecting the pre-amp modules to the T-GEN must have their

shields wired together and connected to the 0V input of J9 (Pin 2) or J1 at the T-GEN. Again the paging

microphone closest to the T-GEN will have priority if both PTT buttons are pressed at the same time.

Note that there are volume controls on both the ALIM and pre-amps(s), we recommend setting the ALIM

volume to maximum and adjusting each microphone separately at its pre-amp.

Figure 6 - Balanced Configuration, PA0688 to T-GEN 50, Non-emergency Microphone

Emergency Microphone For T-GEN

In the above arrangements, the remote microphone will not override tones, digitised speech, or PA

messages generated by the emergency microphone plugged into connector J1.

For an emergency microphone located at the T-GEN a suitable pre-wired handheld microphone with PTT

switch and plug is available (ME0290).

For remotely located emergency microphone(s) we suggest the arrangement shown in Figure 7.

Note that the segments of screened cable connecting the pre-amp modules to the T-GEN must have their

shields wired together and must be connected to the 0V input of J9 (Pin 2) or J1 at the T-GEN. Again, the

microphone closest to the T-GEN will have priority if both PTT buttons are pressed at the same time.

Note that there are volume controls on both the ALIM and pre-amps(s). We recommend setting the ALIM

volume to maximum and adjusting each microphone separately at its pre-amp.

PA0688 MICROPHONE PRE-AMP

SPEECH OUT+

SPEAKER IN +

SPEECH OUT

SPARE

MIC SPEECH IN +

SPEECH IN -

+24V

PTT-

PA0688 MICROPHONE PRE-AMP

SPEECH OUT+

SPEECH OUT -

MIC

+24V

PTT-

PA0846/646 ALIM

A+

A-A-

A+

INPUT OUTPUT

+24V

T-GEN

24V Power

SHIELD

OPTIONAL

(Repeat for further microphones)

SPEAKER IN +

SPARE+

47k

47k MIC+

MIC-

PTT-

LK1A, LK2A NOT FITTED, LK3A FITTED 2-3

Figure 7 - Remote Emergency Microphone(s) for T-GEN 50

LT0371 Issue 1.10 7 February 2018 Page 5 of 6

PA0688 Specifications

Board Dimensions:

157 x 93 x 25mm (lwh)

Shipping Weight:

0.25kg

Temperature:

Operating 0ºC –45ºC

Storage 0ºC –70ºC.

Humidity:

<95% relative humidity (non-condensing)

Operating Voltage:

24V (17-28V) from panel.

Operating Current:

35mA (55mA PTT operated)

Output: (1 khz test tone)

500-700 mV RMS for 1mV in @<10% distortion

600-800 mV RMS for 10mV in @<1% distortion

600-1000 mV RMS for 40mV in @<1% distortion

Nominal Output Impedance:

600 Ohm

Inputs:

MIC+, MIC-, PTT-, +24V (supply)

Microphone Input:

Suitable for dynamic microphone, 600 Ohm

nominal @ 1kHz

Accessories included with PA0688

None.

ME0290 is a suitable PTT microphone (ordered separately).

LT0371 Issue 1.10 7 February 2018 Page 6 of 6

Manufactured

Johnson Controls

Distributed

by:

17 Mary Muller Drive, PO Box 19-545

by:

Christchurch, New Zealand

Tel +64-3-389 5096

Fax +64-3-389-5938

date and are subject to change without notice.

Inhaltsverzeichnis

Andere Johnson Controls Verstärker Handbücher

Johnson Controls

Johnson Controls Metasys AA-30 Bedienungsanleitung

Beliebte Verstärker Handbücher anderer Marken

ASTRO

ASTRO HVO V40 P Bedienungsanleitung

Marantz

Marantz SUPERSCOPE BLA-545 Montageanleitung

NAD

NAD CI980 Bedienungsanleitung

Technics

Technics SE-CH770 Bedienungsanleitung

Harman Kardon

Harman Kardon HK6300 Bedienungsanleitung

NAD

NAD T975 Bedienungsanleitung

McIntosh

McIntosh MA6850 Bedienungsanleitung

Electro-Harmonix

Electro-Harmonix ENGLISH MUFF’N Bedienungsanleitung

Viatron

Viatron Autrix Bedienungsanleitung

GME

GME GA9800 Bedienungsanleitung

Atlas

Atlas CP700 Bedienungsanleitung

Roland

Roland KC-1000 Bedienungsanleitung

Pyle

Pyle PFMRA350BW Bedienungsanleitung

Advantage

Advantage S-250 Bedienungsanleitung

IRT Electronics

IRT Electronics DVA-3007 Bedienungsanleitung

Dimavery

Dimavery BA-100 Series Bedienungsanleitung

Sony

Sony XM-S400D Bedienungsanleitung

Schertler

Schertler ROY X Bedienungsanleitung