03-01-2018, 12:25 PM
(This post was last modified: 03-01-2018, 12:26 PM by Geordie McBoyne.)
(03-01-2018, 11:45 AM)ppppenguin Wrote: I think the EL509 colour LOP valve is rather liked by audiophools for transformerless amps.
And also in single ended audio output stages. It was found when the audio signal is supplied to the screen grid of the EL509 a linear transfer characteristic is possible. The screen grid does however require the signal drive from a cathode follower which uses a high power valve such as an ECL82. Actually, the EL509 isn't a true pentode and is in fact a beam valve designed around the Philips "cavitrap" principle. Likewise the PL500/504.
Geordie McBoyne.
