Qtx 103.120UK User manual

KAD-2
DIGITAL STEREO AMPLIFIER
Item ref: 103.120UK
User Manual
Specifications:
Power Supply 230Vac, 50Hz (IEC)
Output Impedance 4 - 8Ω
Output Power (8Ω) 2 x 25W rms / 2 x 40W max. (EIAJ Standard @ 1kHz 10% THD)
Output Power (4Ω) 2 x 35W rms / 2 x 55W max. (EIAJ Standard @ 1kHz 10% THD)
Input sensitivity : line 380mV
Input sensitivity : mic 15mV
Dimensions 200 x 200 x 65mm
Weight 1.6kg
Version 1.0

103.120UK Manual
Introduction
Thank you for choosing the QTX KAD-2 stereo amplifier. This compact class D digital amplifier is capable
of delivering a powerful 55W max output per channel. With 4 selectable inputs, 2 mic inputs and various
controls, this is a great multipurpose amplifier for both domestic and commercial use.
Product layout:
1. Power switch
2. Volume control
3. Aux input, 3.5mm jack socket
4. Input selection
5. Input bass level control
6. Input treble level control
7. Microphone input echo effect
8. Microphone input tone control
9. Microphone input level control
10. Microphone inputs, 6.3mm jack
11. RCA stereo line inputs
12. Spring clip for FM antenna
13. Spring clip speaker output
14. IEC mains input
Impedance Matching:
KAD-2 is capable of 4-16Ω impedance output if more than one speaker is to be connected to the amplifier
per channel. Please ensure the total impedance of the speakers are within the range.
Speakers can be wired in two different ways, in parallel or in series. The total impedance can be worked
out by the following formulas for the two different ways of wiring:
Parallel Connection - 1/Rtotal = 1/R1+ 1/R2+ 1/R3…….

103.120UK Manual
Series Connection - Rtotal = R1+ R2+ R3…….
Installation:
Before installation, please ensure power is switched off and mains unpluged from the wall to avoid
damage to equipment and installer.
Wire speakers to the amplifier as shown above, ensure the positive and negative terminals are wired
correctly. Audio input on the back is through 3 pairs of RCA connectors, ensure left and right signals are
correct for stereo output. Finally insert the IEC plug and connect the unit to the mains. Before switching
on, always ensure the master volume is set at the lowest point to avoid power surge damage to the unit
or speakers. Adjust the volume accordingly to an appropriate listening level.

103.120UK Manual
Troubleshooting
No Power
Check mains is switched on and power lead is in good condition and fully
inserted into the wall socket.
Check IEC plug is fully inserted into the amplifier on the back.
Check power switch is switched on on the amplifier.
Check if the fuse is faulty. If the fuse blows too frequently, stop use of device
immediately and refer to qualified personnel for repair.
No Music output
Check the input connection lead is fully inserted on both amplifier and source.
Check the correct input is selected.
Check the audio source is playing.
Check volume is turn up on both amplifier and audio source
Check speaker cable is not damaged, end striped and connected properly on
both amplifier and speakers.
Check for any loose strands on speaker cable that is touching the positive and
negative terminal, this will trigger the short circuit protection.
No Mic output
Check Mic is switched on.
Check Mic volume is turned up on the amplifier.
Check if Mic requires phantom power.
Check if Mic is working properly on other device.
Diminishing output
Check speaker polarity is connected correctly.
Check audio source volume is turned up.
Check impedance of the speaker/s is within the range.
Disrupted output
Check output volume is not too high on both audio source and amplifier.
Check for damage on speaker cable and connection leads.
Check amplifier, audio device, speaker and connection cables are not near any
mains power cable or large inductive appliances such as a fridge.
Check location of the bluetooth device is within the reception range of the
amplifier. Range may be significantly reduced in areas where a large number
of electronic / wireless devices are present.
Disposal: The “Crossed Wheelie Bin” symbol on the product means that the product is classed as
Electrical or Electronic equipment and should not be disposed with other household or commercial waste
at the end of its useful life. The goods must be disposed of according to your local council guidelines.
Errors and omissions excepted. Copyright© 2022. AVSL Group Ltd.
Unit 2-4 Bridgewater Park, Taylor Rd. Manchester. M41 7JQ
AVSL (EUROPE) Ltd, Unit 3D North Point House, North Point Business Park, New Mallow Road, Cork, Ireland