The aim of this design was to reproduce a Combo amplifier of the type very common in the `sixties and the `seventies of the past century. It is well suited as a guitar amplifier but it will do a good job with any kind of electronic musical instrument or microphone.
5W power output was a common feature of these widespread devices due to the general adoption of a class A single-tube output stage (see the Vox AC-4 model).
Furthermore, nowadays we can do without the old-fashioned Vib-Trem feature frequently included in those designs.
The present circuit can deliver 10W of output power when driving an 8 Ohm load, or about 18W @ 4 Ohm.
It also features a two-FET preamplifier, two inputs with different sensitivity, a treble-cut control and an optional switch allowing overdrive or powerf