The PrimaLuna Evo 300 is an integrated valve amplifier. I have been meaning to cover one of the Evo family of amps for AVForums for some time now and the circumstances have now come to pass where that is possible. ... 7581A, EL34, EL37, 6550, KT66, KT77, KT88, KT90, KT120 and even the KT150 which is like having four scale models of the Gherkin. The EVO 200 integrated amplifier, the subject of this review, sits within the EVO Series, along with three other integrated amplifier models: the EVO 100, 300 and 400. Moving up from the 100 to 200 and then on to the 300 model, the key difference is larger output and toroidal power transformers. The EVO 300 also adds higher quality.