Class A amplifiers are at the top of the audio and hi-fi spectrum, none more so than Mr John Linsley Hood's classic circuit from 1969. It is a minimalist triumph and is just as relative today as it was when first published in Wireless World Magazine.

This is JLH's circuit from the 1969 article. On the DIY Audio site the JLH thread has reached page 435 last time I looked.

Class A circuits are by their nature very simple and what you put into them is exactly what you get out, but louder. The output transistors are fully 'on' all the time, unlike others which switch on and off as required. This means that there is a lot of heat that has to be borne away by heatsinks and inevitably the actual power to the loudspeakers is quite low. 

But contrary to the rubbish generally accepted that a lot of Watts are necessary, loudspeakers with a db rating of 85 or more are very suitable for the JLH 1969 at 10 Watts and this is far more power than they will ever need. Please read the 'Watts all this then page" for the explanation. 

The Chinese have taken the original circuit and produced inexpensive kits. A pair of which are the subject of my endeavours to make one myself.

For £10 including shipping I bought a pair of kits. The components are all included and the PCB follows the circuit diagram exactly.

How I made the complete amplifier with a power supply is on the 'My build' page