KAD-2

Digital Stereo Amplifier

103.120UK

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

Power switch
Volume control
Aux input, 3.5mm jack socket
Input selection
Input bass level control
Input treble level control
Microphone input echo effect
Microphone input tone control
Microphone input level control
Microphone inputs, 6.3mm jack
RCA stereo line inputs
Spring clip for FM antenna
Spring clip speaker output
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/R_total = 1/R₁ + 1/R₂ + 1/R₃…….

Series Connection

R_total = 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.

Troubleshooting

Question	Answer
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.

Specification

Specification	Value
Power supply	230Vac, 50Hz (IEC)
Output power : 8 Ohms	2 x 25W rms / 2 x 40W max. (EIAJ Standard @ 1kHz 10% THD)
Output power : 4 Ohms	2 x 35W rms / 2 x 55W max. (EIAJ Standard @ 1kHz 10% THD)
Output impedance	4 - 8 Ohms
Input sensitivity : line	380mV
Input sensitivity : mic (unbalanced)	15mV
Finish	Black
Dimensions	200 x 200 x 65mm
Weight	1.6kg

Precautions

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.