• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

PFL200, what can I use them to?

Hi friends

I have some PFL200 (16Y9). They are just lying around. :eek:

Are there some who have tried them in audio use. I can not find anything on Google.

Key figures would be:
Va = Vg2 = 170V
Vg1 =-2.6v
Ia = 30 mA
Ig2 = 6.5 mA
Raa = 5 or 8 k since I have both. Which is best?
Wout = 4 to 6 Watt

The small pentoder be triode connected and used as input stage and phase splitter.

Are there some who have ideas?




2009-02-02 9:41 am
Are there some who have ideas?



Your biggest enemy is the uncommon socket. Where do you plan to plug these in ? If you have sockets ready, you can move on to more technical aspects.

PFL200 is a signal pentode and an output pentode. Output pentode is rated for 5.1W anode dissipation. The only use I see for it outside TV service (assuming you managed to procure the odball sockets) would be a single-ended headphone amplifier, or low-wattage amplifier (1-2W audio output power or thereabouts). There's far too much gain for any other use (you might as well use solid state if you're content with loads of gain and NFB and triode connection of either section) which just makes a poor use of what is already a rather unwieldy tube.
If you want to try something extraordinary, I believe it would be possible to make a murray amplifier with 2 of those tubes..

Advantages are, it would need around 350V B+ instead of the very low 170V (so you can use a more common power transformer)
You will not be able to use the output transformers you already have, but a cheap toroid will do very nicely here!

(schematic of murray amp is here )

Just an idea!

PS: thanks about the tip for the sockets guys