Here is the scematic I used.
I used a mosfet to drive the grid. However I suspect this paticulair device (Buz80) is not suited to the job. I suspect is has high gate capacitance.
The potentiometer feeding the mosfet gate sets the voltage on G2, and hence the current through the tube. I have stabilized this supply whit a 100volt Zener diode. whit this resistor 47K and 100K potentiometer , the zener diode conducts about 4mA .
I also left the Triode cathode resistor and anode resistor value blank. the Philips datasheets for Ecc8X tubes will tell you the appropriate values for the voltage swing required.
V4lve
I used a mosfet to drive the grid. However I suspect this paticulair device (Buz80) is not suited to the job. I suspect is has high gate capacitance.
The potentiometer feeding the mosfet gate sets the voltage on G2, and hence the current through the tube. I have stabilized this supply whit a 100volt Zener diode. whit this resistor 47K and 100K potentiometer , the zener diode conducts about 4mA .
I also left the Triode cathode resistor and anode resistor value blank. the Philips datasheets for Ecc8X tubes will tell you the appropriate values for the voltage swing required.
V4lve
hello ,
Well, j have 2 series of tubes loan has to work, put into series EL 508 and the series 6P41C, but the brocading is different.
J have the complete brocading for the series EL 508 but not for the series 6P41C, I thus look for correspondence?
J have to test the series EL 508, I would want to make compatible, 2 series without too much modification!
tks 😉
Well, j have 2 series of tubes loan has to work, put into series EL 508 and the series 6P41C, but the brocading is different.
J have the complete brocading for the series EL 508 but not for the series 6P41C, I thus look for correspondence?
J have to test the series EL 508, I would want to make compatible, 2 series without too much modification!
tks 😉
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hello V4lve Lover ,
The tube 6P 41 C has t he them even technical values which EL 508 in service ?
If yes, I would make of the custom-made product.
The tube 6P 41 C has t he them even technical values which EL 508 in service ?
If yes, I would make of the custom-made product.
I'm not certain if they are the same.
You could certainly try the tube in the schematic I posted. It will likely work.
You could certainly try the tube in the schematic I posted. It will likely work.
hello ,
the end build ...😀
the build is SE UL EL 508 and ...2 x 3.5 W 🙄 , nice performance
listing valve : 1 EZ81 hybride / 1 N4007 - 1 12AU7WA - 2 x EL 508 .
listing Transfo : 1 for BT ( 6.0 V ) / HT ( 230 V ) and 2 OPT 5K UL / 8 Ohms for EL 84 .
the end build ...😀
the build is SE UL EL 508 and ...2 x 3.5 W 🙄 , nice performance
listing valve : 1 EZ81 hybride / 1 N4007 - 1 12AU7WA - 2 x EL 508 .
listing Transfo : 1 for BT ( 6.0 V ) / HT ( 230 V ) and 2 OPT 5K UL / 8 Ohms for EL 84 .
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That´s a neat build Jean Michel, it seems the pl508 have no problems with the 2nd screen voltage, but you could also run the tube like a pentode making a regulated supply for the screens.
Because those tubes were meant to run for lowish voltages in switching aplications, for tv's
Because those tubes were meant to run for lowish voltages in switching aplications, for tv's
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I also have a PL508 amp in mind
Attachments
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