Articolo pubblicato sul numero 420 di maggio-giugno 2020 di Audio Review. 
Si ringrazia il Direttore Mauro Neri per l'attenzione e la disponibilità

BIBLIOGRAFIA:
(1)  S. SEELY, “Electron Tube Circuits”, Chapter 9-Untuned Power Amplifier. 9-6 Push Pull Amplifier.
        (Mc Graw-Hill Book Company, Inc. – New York, 1950)
(2)  S. SEELY, “Electron Tube Circuits”,
        Chapter 3 – Vacuum Tube as Circuit Elements. 3-6 Harmonic Generation in a tube.
        (Mc Graw-Hill Book Company, Inc. – New York, 1950)
(3)  F.E. TERMAN, “Radio Engineering” – third edition – Chapter 18 – Sound and Sound
         Equipment. 18-4 Effects of Distorsion in the Reprodution of Sound.
          (Mc Graw-Hill Book Company, Inc. – New York, 1947)
(4)  NOR-SE Srl – via C. Colombo II/I , 26010 Dovera (CR)
        www.nor-se.com
(5)  S. SEELY, “Electron Tube Circuits”,
        Chapter 2 – Characteristics of ElectronTubes. 2-5 Triode parameters. (Mc Graw-Hill Book Company, Inc. – New York, 1950)
(6)  S. SEELY, “Electron Tube Circuits”, Chapter 9-Untuned Power Amplifier. 9-2 Output Circuits.
        (Mc Graw-Hill Book Company, Inc. – New York, 1950)
(7)  F.E. TERMAN & T.M PETTIT, “Electronic Measurements” – second edition – Chapter 6 –
        Waveform, Phase and Time interval Measurements.
        (Mc Graw-Hill Book Company, Inc. New York, 1952)