Wiring a 12au7

[A3rd.Zero]

I am using a 12au7 in a preamp and I have questions about wiring it to the 6.3volt supply. I have heard that you can use a 12au7 on a 6.3volt supply somewhere but I cant figure it out. Unfortunatly I only have one 6.3volt winding on my transformer so I may be out of luck. Can anyone tell me how to do this?

Thanks

Milo

 

[Sch3mat1c]

Tie pins 4 & 5 together, connect 6.3V across pins 4+5 and 9. Just connecting both halves in parallel.

Tim

 

[A3rd.Zero]

Sweet. Thank you very much. I had thought for a moment that I had screwed the pooch big time.

Milo

 

[A3rd.Zero]

Hang on. Isn't that the way you would wire any tube that takes 6.3V to a 6.3V supply (Ie a 6Dj8)? The 12Au7 is a 12.6V tube though.

I am sorry if I'm beting an idiot, Im still getting the hang of this stuff.

Thanks for your help.

Milo

 

[SY]

Milo, no, you hook up a 6DJ8 by running 6.3 v between pins 4 and 5. They're not tied together in that case. Pin 9 in that family isn't a heater center-tap, it's usually a shield.

 

[A3rd.Zero]

So what should I do with the 9pin on a 6DJ8 tube? leave it alone or ground it? Thanks for your help, I really appreciate it.


Milo

 

[SY]

In most cases, just leave it alone.

 

[A3rd.Zero]

Thank you Sch3mat1c

Thank you SY

I think I can build my amp now. mmmmmmmm, tube amp


milo

 

[s2kov]

Tie pins 4 & 5 together, connect 6.3V across pins 4+5 and 9. Just connecting both halves in parallel.

Tim

How about connecting both halves in parallel if you have 6.3V Center Tapped (3.25-0-3.25)? Where do you think i can connect Pin 9?

Thanks....

 

[cogsncogs]

pin 9?

s2Kov,

How about connecting both halves in parallel if you have 6.3V Center Tapped (3.25-0-3.25)? Where do you think i can connect Pin 9?

Like this.

Wayne

 

[s2kov]

How about connecting both halves in parallel if you have 6.3V Center Tapped (3.25-0-3.25)? Where do you think i can connect Pin 9?

Thanks....

Thanks wayne....

 

[s2kov]

Heater Current

Guys,

In addition to my previous question, assuming i use to two (2) 12au7 and both halves connected in parallel. What is the required current for the transformer? Is it 0.6A for two twin triode?


Thanks....

 

[s2kov]

Anyone????

Thanks wayne....

 

[Sch3mat1c]

Each heater half uses 6.3V at .15A. Add it up.

Tim

 

[s2kov]

Thanks Tim.

Appreciate your help....

Anyone????