Custom PA300 Amplifier
Custom DIY amplifier
It's a modification of an old and popular design, published in ELEKTOR magazine back in 1995. You can see original design on this link.
The modification is primarily designed to allow operation under more severe heating conditions(read, working in clubs). To accomplish this I changed protective circuit to prevent blowing up in short circuit conditions.
Original schematic is on bellow picture.
Schematic with modified protective circuit is on next picture.
The basic idea is to modify the system by working with active cooling. In original design system is cooled by large passive cooler. My idea was to to move the output transistors from the original PCB and put them on coolers designed to make an air tunnel.
During the development, several versions have been created. First of all, the amplifier PCB was changed and also the power supply PCB board was changed. The cooling system was not changed and proved to be very efficient. The very first prototype is on next picture.
Picture 3 (the picture is blurry, but it has wonderful memories)
Design was really nice as for the working in extreme conditions. But I needed to integrate as much as possible on amplifier PCB. In that time I was working with Eagle, now Autodesk product. this led to the following PCB and housing design.
The last unit I made using the above design never left my workshop and is still standing and waiting for finalization. You can see work in progress on next pictures.
Please note that if you building this, you do it on your on responsibility.
It's a modification of an old and popular design, published in ELEKTOR magazine back in 1995. You can see original design on this link.
The modification is primarily designed to allow operation under more severe heating conditions(read, working in clubs). To accomplish this I changed protective circuit to prevent blowing up in short circuit conditions.
Original schematic is on bellow picture.
Schematic with modified protective circuit is on next picture.
The basic idea is to modify the system by working with active cooling. In original design system is cooled by large passive cooler. My idea was to to move the output transistors from the original PCB and put them on coolers designed to make an air tunnel.
During the development, several versions have been created. First of all, the amplifier PCB was changed and also the power supply PCB board was changed. The cooling system was not changed and proved to be very efficient. The very first prototype is on next picture.
In next version I changed housing. It was 4RU. Pictures from that iteration are below.
Design was really nice as for the working in extreme conditions. But I needed to integrate as much as possible on amplifier PCB. In that time I was working with Eagle, now Autodesk product. this led to the following PCB and housing design.
The last unit I made using the above design never left my workshop and is still standing and waiting for finalization. You can see work in progress on next pictures.
Please note that if you building this, you do it on your on responsibility.
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