Cambridge Audio A4 Stereo Amplifier Mods

In this video, Steve disassembles a Cambridge Audio A4 Integrated Amplifier which he rescued before it was thrown away. The amplifier is refurbished with new electrolytic capacitors and a clean inside before performing a modification to make the dials on the front panel glow.

 

Laser Cut Acrylic Rings  - To dissipate the light

Laser Cut Acrylic Rings – To dissipate the light

Testing the acrylic rings with an LED

Testing the acrylic rings with an LED

 

The video of the process is here on YouTube:

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Acoustic Solutions Hi-Fi Amplifier Repair and Teardown – Error U52, U53

In this video, Steve performs a Hi-Fi Amplifier repair and teardown on an Acoustic Solutions SP101 Hi-Fi Amplifier that displays Error U52 or U53 on the display. The amplifier is unable to store tone and balance settings and doesn’t always respond to changing the volume with the rotary encoder.

The video walks through the design of the amplifier, the repair and also the replacement of the rotary encoder.

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LCD Monitor Repair and Teardown – BenQ 19″ LCD Monitor

In the following videos, Steve performs an LCD monitor repair on a faulty BenQ 19″ Monitor that would not power up correctly and regularly displayed the ‘Auto Adjust’ message.

The Peak Atlas ESR70 meter is used to test suspicious electrolytic capacitors in the power supply.

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Designing a Constant Current LED Driver – Part 2

In this video Steve interfaces the DC-DC converter circuit with a Microchip dsPIC33FJ16GS502 microcontroller to create a microcontroller-based constant current LED driver.

The dsPIC33FJ16GS502 microcontroller has four analogue comparators which allow expandability to 4 independent constant current channels.

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Designing a Constant Current LED Driver – Part 1

In the first episode of a complete video series, Steve begins the design of a constant current LED driver. This aim of this project is to create a four channel high power LED driver that can interface with an RS-485 or IEEE 802.15.4 MiWi network. This will allow control of multiple light fixtures or multicolour mood lights from one or more lighting controllers.

This first episode focuses on the design of the DC-DC converter which is optimised for use on a 24V power bus which a high switching frequency for small size. The components can be changed for other applications (different supply voltages or switching frequencies) using the concepts introduced in this video.

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