The JA80 is a power amplifier working in pure class A. It is the first amplifier created by the JADIS in 1983; it has been upgraded several times but remains the flagship of the brand.

It works in a "push-pull" configuration with triple load and autobias. It can work with various types of penthodes: KT120, KT90, KT88, 6550, 6CA7 or EL34. The MkII version brings the compatibility with the KT150 pentodes.