28 3/4″ x 9 1/2″ x 9″. All valve (cathode biased). Single channel. A JMI design (Derek Underdown).

VALVES:  normally* ECC83, ECC807 and ECC88 in the preamp, EZ80 rectifier, and 2 x EL84. Around 10-12W output.

CONTROLS: volume, treble, middle, bass; top boost switch; speed and depth (tremolo); reverb.

EFFECTS: tremelo and reverb switched on or off via a footswitch.

SPEAKER CABINET: 28 3/4″ x 19 1/2″ x 11 1/4″. 2 x 10″ – two Celestion 7442s. Provided either with side stands, or a swivel trolley with a top bar for the amp to sit on. Metal loops under the amp and tongues on top of the cab kept the amp in place when side stands were present.

*    “…Later models had  three ECC83s in the preamp, EZ81 rectifier, and 2 x EL84.  The use of the rare ECC807 is important. This is an ultra high gain valve, and really makes a difference to the sound, which is brilliant and very responsive. The pinouts on the ECC807 are also different from the standard ECC82/83 types, so you can’t just plug in one of those without damaging the amp. Unfortunately the ECC807 was a military valve, and production ceased in the mid-60’ies, so if you don’t have a spare, then you have to convert the amp to a more conventional ECC83-based layout.” (Frank Carvalho)

sound files on Frank Carvalho’s site – http://www.etcetera-music.eu/public/instruments/Vox/710/

another one here