Every audio amplifier is made basically of three blocks, each one with different purposes:
- Voltage Amplifier – it receives the input signal with high impedance (tipically 47kohm) and amplifies it so that can drive the driver stage
- Driver Stage – is places between Voltage Amplifier and Output Stage and adapt and sometime “processes” the signal so that can drive the output stage
- Output Stage – is the final block in charge of deliver high currents, so that the amplifier can handle low-resistance loads such as a speaker
The project that I’m about to present is an output power stage, capable to handle more than 500w if mounted on a suitable heatsink.
Gainclone or chipamp is a term commonly used to describe a type of audio amplifier made by do-it-yourselfers, or individuals interested in DIY audio. It is a design based on high-power integrated circuits, particularly the National Semiconductor Overture series. The Gainclone is probably the most commonly built and well-known amplifier project amongst hobbyists. It is simple to build and involves only a few readily accessible, inexpensive parts. As an amplifier it is highly regarded by many in the DIY community. (from wikipedia http://en.wikipedia.org/wiki/Gainclone)
No one can describe the gainclone’s philosophy better than this wikipedia page!
Tha gainclone is an easy-to-built, cheap, hifi quality, simple amplifier made with few components. I’ve decided to create a gainclone version myself, doubling the output power and using the idea from an old application note from National Semiconductor, talking about the parallel amplifier PA100.