[sdiy] B+ Current consumption

[Antti Huovilainen]

On Tue, 16 Jan 2007, Michael Ruberto wrote:

> I am hunting for a transformer for my single tube preamp and was wondering 
> how much current I will need for the B+ supply. Any ideas here?

Depends on the tube. 12ax7 will need about 2-4mA, 12au7 maybe 10-20mA.

> Also, if the circuit calls for 150V can I get away with using a 300V 
> transformer with a voltage divider on the output or will this cause loading 
> problems?

If you need to drop voltage you can use several high power zeners in 
series.

Antti

"No boom today. Boom tomorrow. There's always a boom tomorrow"
   -- Lt. Cmdr. Ivanova