Because the production of high-quality semiconductor materials was still decades away, Lilienfeld's solid-state amplifier ideas would not have found practical use in the 1920s and 1930s, even if such a device had been built.
Debido a que a produción de materiais semicondutores de alta calidade non estaba dispoñible por entón, as ideas de Lilienfeld sobre amplificadores de estado sólido non atoparon un uso práctico nos anos 1920 e 1930, aínda que un dispositivo deste tipo xa se construíra.