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Triode curves for EL/PL519

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Adolf Corkscrew

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Joined 2010
#1
Hey,

I was looking for triode curves on the EL/PL519, but found nothing on the goode olde google. I was thinking of making a push-pull amp in Class A triode mode with some of the PL519's I happen to have around. But the Philips datasheet only gives a single pentode curve set... So, if any of you have any idea where to find a decent triode curve set, please share the info with me.
 
#2
Sorry - don't have triode curves for the '519 but I have successfully used triode strapped/ UL line output valves with great results in the past. The thing to watch is that the screen voltage ratings limit HT in your amp to this rating. I have used a supply of +300V for 6CM5/EL36 which is 50V higher than the databook screen rating - wouldn't like to go much higher! The '519 has the same 250V max screen rating.
 
#3
It is not screen voltage rating that you should worry about, it is screen power dissipation that depends on screen current and voltage. In pentode mode when anode voltage goes below screen grid voltage screen grid current goes sharply up. In triode mode it does not happen.
 
#5
jane said:
Here are triode curves for EL509/6KG6:
Audiofil - feel the sound - forum: PL504 + Visaton TR84
Click to expand...

Thank you for this. The PL519 and 509 should be electrically quite similar, the former only having slightly higher ratings, if I remember right?

So, in triode the plate resistance seems to be ridiculously low, but also µ is very low, so driving this will take some grunt... Then again, with low rp, the winding ratio will be smaller than with the likes of KT88 and such, so maybe the low µ won't be such a problem.
 
#7
Wavebourn said:
It is not screen voltage rating that you should worry about, it is screen power dissipation that depends on screen current and voltage. In pentode mode when anode voltage goes below screen grid voltage screen grid current goes sharply up. In triode mode it does not happen.
Click to expand...

i believe that a resistor from screen tied to plate is used to make sure that plate voltage stays on top of screen voltage....said another way, the resistor ensures that screen voltage stays lower than plate voltage....😀
 
#9
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