KAD-2 - Hi-Fi System Qtx - Free user manual and instructions

Product Type	Stereo amplifier
Brand	Qtx
Model	KAD-2
Power Supply	230Vac, 50Hz (IEC)
Output Impedance	4 - 8Ω
Output Power (8Ω RMS)	2 x 25W RMS
Output Power (8Ω Max)	2 x 40W max
Output Power (4Ω RMS)	2 x 35W RMS
Output Power (4Ω Max)	2 x 55W max
Input Sensitivity (Line)	380mV
Input Sensitivity (Mic)	15mV
Dimensions	200 x 200 x 65mm
Weight	1.6kg
Inputs	3x RCA stereo (Line, CD, AUX), 1x 3.5mm Aux, 2x 6.3mm Mic
Speaker Outputs	Spring clip speakers (4-16Ω)
Controls	Master Volume, Input Selection, Bass, Treble, Echo, Tone, Mic Volume
Protection	Short circuit protection
Fuse	F5A 250V

Frequently Asked Questions - KAD-2 Qtx

What is the maximum power output per channel?

The maximum output power is 55W per channel at 4Ω (EIAJ Standard @ 1kHz 10% THD).

How many microphone inputs does the KAD-2 have?

It has two 6.3mm jack microphone inputs with independent volume controls.

Can I connect Bluetooth devices?

The manual mentions a Bluetooth antenna terminal (spring clip for FM antenna). However, the KAD-2 does not natively support Bluetooth; external Bluetooth receivers can be connected via AUX or LINE input.

What is the recommended speaker impedance?

The amplifier can handle speakers with an impedance of 4-16Ω. Ensure total impedance per channel is within this range when connecting multiple speakers.

How do I connect speakers in parallel or series?

For parallel connection: 1/R_total = 1/R_1 + 1/R_2 + ... For series: R_total = R_1 + R_2 + ... Check the manual for diagrams.

What should I do if there is no sound output?

Check input connections, ensure correct input is selected, verify audio source is playing, and that volume is turned up. Also check speaker cables are not damaged and properly connected.

Why is the microphone not working?

Ensure the mic is switched on, mic volume is turned up, and the mic does not require phantom power (KAD-2 does not provide phantom power). Test the mic on another device if possible.

How do I clean and maintain the KAD-2?

Disconnect from mains before cleaning. Use a dry cloth or lightly dampened cloth with mild detergent. Avoid solvents. Keep ventilation slots clear.

Where can I find spare parts or repair service?

Contact Qtx or an authorized service center. Only qualified personnel should replace the fuse or perform internal repairs.

What are the dimensions and weight of the unit?

Dimensions: 200 x 200 x 65mm; Weight: 1.6kg.

USER MANUAL KAD-2 Qtx

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

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/R_total = 1/R_1 + 1/R_2 + 1/R_3 .....

Series Connection - R_total = R_1 + R_2 + R_3 .....

Installation:

Before installation, please ensure power is switched off and mains unplugged 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

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.