Jennings Musical Industries (JMI) 1966 / 1967

For other pre-production amps, see this page. Standard production Defiants, which are very different, can be found here.


Legend for "Distortion" was erased at some point. VOX logo now gone, marks of the glue remain.

BOX - no. 15 in chalk on the back panel.

Back panel signed "DH". "Ko" in large letters inside the box on one side. On the opposite side "K" scratched in. Front grille signed "MAY".

Thinner sides and bottom than production boxes. Staples and preamp standoffs are brass. Front panel attaches differently. Corners are reinforced with triangular inserts. There is a runner, front bottom, to support the preamp section.

Tolerances are extremely tight. An 1/8" here or there and the preamp section would not fit.

PREAMP - no. 16 (on blue dymo tape).

Again, substantially different from production amps. Some later changes. The DIN socket has been replaced by a jack.

POWER AMP - no. 18 (on red dymo tape).

Transformer central on chassis. Large diodes on central underside tagboard. Large mains inlet. Voltage selector in centre (corresponding to position of mains transformer). Twin output jacks. Legends substantially different.