Elevated 6.3V AC supply with 6.3V DC regulated supply?

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Jana
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Location: Minnesota

Re: Elevated 6.3V AC supply with 6.3V DC regulated supply?

Post by Jana »

"but then you'd need another winding somewhere just for that elevation voltage."

Or you can use a voltage divider on the B+ and use that to elevate the heaters.
diagrammatiks
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Re: Elevated 6.3V AC supply with 6.3V DC regulated supply?

Post by diagrammatiks »

jgrg1 wrote:After all that, having checked the power transformer, it looks like I won't have enough juice to power the 2xEL34s + 4xECC83 (and relays) anyway, so I'm going to install a second power transformer to get 12.6v DC for the preamp tubes.

I planned to DC elevate the 6.3v heaters anyway, but just out of curiousity, could I power this from a completely dedicated rectified DC source instead of from the tail end of the HT line? What would be the current draw on that DC source - assuming that the DC was fed into two 100R resistors connected across the 6.3V lines?
diagrammatiks wrote:ya you could of course.

but then you'd need another winding somewhere just for that elevation voltage.
Jana wrote:"but then you'd need another winding somewhere just for that elevation voltage."

Or you can use a voltage divider on the B+ and use that to elevate the heaters.
:?:
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M Fowler
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Location: Walcott ND

Re: Elevated 6.3V AC supply with 6.3V DC regulated supply?

Post by M Fowler »

Just use a voltage divider off the B+5 to get between 50 to 70 volts wired to the CT or if no CT to the filament string 100 ohm resistors.

Why DC the whole string? If anything you can AC filament the power tubes and then use rectifier after the power amp tubes to run DC for the preamp tubes. This is done in many high gain amps.
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