Note: The four input jack-sockets with the three rotary controls on the right hand side of the back plate are not original. The single jack-socket in the lower center will be the original input.
The early Fidelity HF 3 utilized a single EL83 preamp valve, a single EL84 power stage valve, and a metal rectifier.
The manufacture date of 27th November 1958 inside the cabinet.
Fidelity Radio Ltd Advert from April 1959, which offers the Fidelity HF3 Guitar Amplifier for sale at the price of 10 Guineas.