DC heater help

[joesatch]

PT is delivering 13.7vac @ 2a before the rectifier circuit. I want to power 4 preamp tubes (this is a preamp so no PI). Will this be enough current?  Valve wizard seems to indicate no?

[pdf64]

Presumably you’ll be arranging each valve’s heater in series for 12V 0.15A operation, rather than parallel for 6.3V 0.3A, per valve?
Hence IDC will be 0.6A, and so IAC will be about twice that, eg 1.2A.
I think you’ll definitely need a dropping resistor, as you may have about 18V at the reservoir cap.

[joesatch]

Actually using a Headfirst DC heater board so it's all filtered and regulated delivering 12vdc. So i will wire up the heaters in series which will draw less current?  Are there any examples of this drawn out? Appreciate your help.

HF diagram shows the 12vdc heaters wired like this . This looks like parallel to me,

[joesatch]

i believe i understand. The pic i posted is wired in parallel in relation to the tubes in a pair but actually wired in series on each individual tube. I didnt think tubes could be wired in series in relation to each other (daisy chained)

[sluckey]

HF diagram shows the 12vdc heaters wired like this . This looks like parallel to me,

That's the correct way to wire two tubes. Notice that pin 9 is not being used? There are actually two 6.3v filaments inside a 12AX7 tube. The tube can be powered from 6.3V or 12.6v. We usually connect the two internal filaments in parallel by connection pins 4 and 5 together and connecting the 6.3V supply to pins 4/5 and 9. To operate the tube from a 12.6 supply you would simply connect the 12v source to pins 4 and 5 and ignore pin 9. So, in that sense, the two internal 6.3v filaments are connected in series when operating from a 12v source. If this sounds confusing, look at a pin diagram for a 12AX7.

[joesatch]

HF diagram shows the 12vdc heaters wired like this . This looks like parallel to me,

That's the correct way to wire two tubes. Notice that pin 9 is not being used? There are actually two 6.3v filaments inside a 12AX7 tube. The tube can be powered from 6.3V or 12.6v. We usually connect the two internal filaments in parallel by connection pins 4 and 5 together and connecting the 6.3V supply to pins 4/5 and 9. To operate the tube from a 12.6 supply you would simply connect the 12v source to pins 4 and 5 and ignore pin 9. So, in that sense, the two internal 6.3v filaments are connected in series when operating from a 12v source. If this sounds confusing, look at a pin diagram for a 12AX7.

Totally understand. Going back to my original question. Can i power 4 ecc83's with 12vdc @ 2a ?

[shooter]

re-read reply #1

[sluckey]

Totally understand. Going back to my original question. Can i power 4 ecc83's with 12vdc @ 2a ?

Absolutely. 4 ecc83s will only draw .6a @ 12vdc.

[PRR]

....I didnt think tubes could be wired in series in relation to each other (daisy chained)

For decades most US radios and TVs ran "series string". I bet you don't know series string holiday lights?

Here's a medium-bad example:

[thetragichero]

no power transformer isn't *super* bad when it's inside a nice bakelite container with no hands touching metal parts. can be VERY bad when the chassis is connected the the guitar cable shield, bridge ground, YOU