Building Compact F5 Amplifier (Part 3) PCB & Heatsink Mounting

Every end of the year, I don't know why I am always make a new amplifier. Maybe the hot season already left behind and the chill wind blowing in the morning refreshing my mind. I have more energy to build something like this one, the compact F5 amplifier.

Right now I am using the PCB for the very first time since 12 years ago. This F5 amplifier is pretty simple and point-to-point is not difficult to make. But I already had this PCB on hand, not using it will be a waste. The PCB quality are very good, although I found some mark on the fet is wrong but overall this is the best PCB I can get from my local forum member.

I also check the best possible placement for the final transistor.

I guess this is the final layout.

Then I will put the final Transistor attach to the heat sink. Surface of the heatsink need to be clean before installing the fet on it. By doing this will improve the heat transfer.

I still have a CPU thermal paste from my previous PC project. This thermal paste is better than my any standard thermal paste. It is from Deep Cool Z5. The specification on the datasheet claims that it has more material that transfer heat quickly.

Before apply this paste, the fet pins need to be adjusted.

Using the short cable to extend the leg and attach them to the PBC is not the best idea, but this is the best solution for non universal heat sink like this case.

Still nice isn't it?

Remember to use mica spacer to avoid short circuit between body of the fet and the heat sink grounding.

One cable is attach just like the pig tail. It is for easy ground connection in the process.

The input cable is from Canare. It is a shielded cable to avoid signal noise.

It attach the cable directly on the back of the PCB. The hole is not large enough to fit this cable.

Little amount of thermal paste is enough. In this picture, I add to much.

Attaching the fet to the heat sink and secure it with a bolt.

At the side, you will notice I am using a big washer just like Mr. Nelson did. The thermistor is located near the fet and touch the heat sink.

The final result would be like this. All I have to do now is connecting the power and speaker out cable.

I am stop this project at the moment. I still need few components such as one piece of 2SJ74 which already hard to find here.

The final part can be found here

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