Bias circuit addition

[navdave]

Hi all I need to add a stable bias supply to a tube amp build. Which transformer would yield more voltage when hooking it to the tube heater voltage supply a 6.3/120 or 12.5/120?

[sluckey]

Hi all I need to add a stable bias supply to a tube amp build. Which transformer would yield more voltage when hooking it to the tube heater voltage supply a 6.3/120 or 12.5/120?

The 6.3v transformer would produce 120vac. The 12.5v transformer would produce 60VAC.

[tubeswell]

I'd go with the 12V one myself

[navdave]

Alright thank you very much I thought the 6.3v would yield 120v I'm a go with the 6.3 my b+ is very high over 500vdc thanks again!

Hi all I need to add a stable bias supply to a tube amp build. Which transformer would yield more voltage when hooking it to the tube heater voltage supply a 6.3/120 or 12.5/120?

The 6.3v transformer would produce 120vac. The 12.5v transformer would produce 60VAC.

[ernie_jr]

the 12.6 tranny will give you 84volts dc (60 x 1.4). i have used this in many sunn builds that have over 500 volts on the plates. 84 volts is plenty. if you use the 6.3 volt tranny to get 120 volts it may be harder to get the voltage down. All sunn amps had a 60 volt tap on there power tranny.
good luck.
Ernie