background image

General Installation 

DO NOT 

run unbalanced high impedance 

microphone cables near mains, data, 
telephone or 70/100V line cables.

DO NOT 

run 70/100V line cable near data, 

telephone or other low voltage cables.

DO NOT 

exceed 90% of the amplifiers output 

power when using 70/100V line (speech only).

DO NOT 

exceed 70% of the amplifiers output 

power when using 70/100V line (high level 
background music).

DO NOT 

use voice paging horn loudspeakers 

for background music unless the loudspeaker 
has been specifically designed for this 
purpose.

AVOID 

jointing the microphone cable, 

when this is unavoidable make sure a good 
screened connector is used. 

ALWAYS 

use balanced low impedance 

microphone cable terminating to balanced 
inputs on long cable runs.

ALWAYS 

use a mains grade double insulated 

cable for the loudspeaker cable runs when 
run in conduit together with power cables. 

ENSURE 

that all loudspeakers are in-phase.

ENSURE 

that there are no short circuits on 

the loudspeaker line before connecting to the 
amplifier. It is also advisable to check the final 
impedance to the amplifier with a dedicated 
impedance meter to determine power draw is 
within the amplifiers limits.

IMPORTANT

The wires in the mains lead are coloured In 
accordance with the following code:

Green and Yellow:

    Earth (E)

Blue:   

            

Neutral (N)

Brown:     

      

Live  (L)

As the colours of the wires in the mains lead 
of this apparatus may not correspond with the 
coloured markings identifying the terminals in 
your plug proceed as follows:

The wire which is coloured green and yellow 
must be connected to the terminal which is 
marked with the letter N or coloured black.  
The wire which is marked with the letter L or 
coloured red. 

If a 13 Amp (B.S.1363) plug or any other type 
of plug is used, a 5 Amp fuse must be fitted 
either in the plug or at the distribution board.

WARNING  

THIS APPLIANCE MUST BE EARTHED

Summary of Contents for QTA 2120P

Page 1: ...Q Tech Q Tech Commercial Series QTA 2120P 2240P 2 Channel Power Amplifiers User Manual ...

Page 2: ...run in conduit together with power cables ENSURE that all loudspeakers are in phase ENSURE that there are no short circuits on the loudspeaker line before connecting to the amplifier It is also advisable to check the final impedance to the amplifier with a dedicated impedance meter to determine power draw is within the amplifiers limits IMPORTANT The wires in the mains lead are coloured In accorda...

Page 3: ...Tech Commercial Series QTA 2120P 2240P 1 Contents Introduction 2 Description 2 Front Panel Layout 3 Rear Panel Layout 3 Power Source 4 Main Connections 4 Installation Practice 4 Operation 5 Trouble Shooting 5 Specifications 6 Technical Notes 6 ...

Page 4: ...llation is completed with the same attention to detail your amplifier will deliver its best results Please read the section Constant Voltage Distributed Speaker Systems Demystified Unpacking Please inspect the amplifier carefully immediately after unpacking If you find any damage notify your supplier dealer immediately Only the shipper may file a damage claim with the carrier for damage incurred d...

Page 5: ... Terminal 8 Channel 2 XLR Input 3 Channel 2 Speaker Terminal 9 Channel 1 Link Output 4 Channel 1 Speaker Terminal 10 Channel 1 Phone Jack Input 5 24v DC Power Input 11 Channel 1 XLR Input 6 Channel 2 Link Output 1 Power On Off Switch 4 Signal Indicators 2 Power On Indicator LED 5 Peak Indicators 3 Channel Volume Controls 6 Protection Indicators 7 6 5 8 9 10 11 1 2 3 4 1 2 4 5 6 3 ...

Page 6: ...ce Step 1 Take a piece of figure 8 cable connect the stripe coloured wire to the 100V terminal and the uncoloured wire to the COM on the amplifier terminal strip Step 2 Connect the other end of the wire uncoloured to the Com EARTH connection on the ceiling speaker transformer and the other strip wire to the required voltage taping Step 3 Take a second piece of figure 8 cable and connect the plain ...

Page 7: ...in the course of installation This can be common with building sites with multiple trades people installing equipment into the same ceiling cavities as the audio system Operation After all connections are completed turn on the power If necessary turn the gain control on the rear panel to what you desire We suggest turning the gain level to maximum always Trouble Shooting If the amplifier fails to ...

Page 8: ...ut can be quite involved but there is a simple technique for not overloading the amplifier As for the amplifiers there are two common standards 100 Volt line in Europe and Asia and 70 Volt line on the American continent For the purpose of simple calculations we will use the European standard for this exercise On the rear of a 70 100V amplifier you will find an output terminal strip This terminal s...

Page 9: ...heating of the amplifier and generally poor performance The problem is not really too many speakers it is more a problem of too much wattage draw exceeding the output capability of an amplifier A similar problem would be trying to draw 2 000 watts from a 1 000 watt generator Sooner or later Expect a system failure Let us take a 100 watt amplifier If you have 20 speakers and you set them at the 5 w...

Page 10: ...KΩ 10W 1KΩ 40W 250Ω 0 5W 20KΩ 15W 667Ω 50W 200Ω 1W 10KΩ 20W 500Ω 75W 133Ω 2W 5KΩ 25W 400Ω 100W 100Ω 3W 3 33KΩ 30W 333Ω 150W 66 7Ω 5W 2KΩ 35W 286Ω 200W 50Ω 100V plan P E x E Z 100x100 Z 10 000 Z P Power W Z Impedance Ω E 100V Designed voltage of a general use amplifier High impedance of speakers and output calculation table for 100Volt systems ...

Page 11: ......

Page 12: ...www questaudio net Quest Engineering Pty Ltd 86 Derby St Pascoe Vale VIC 3055 Ph 613 9354 9133 Fax 613 9354 9233 ...

Reviews: