single end 5w

[snakepit]

hi there i am george and i'm a newbie in tube amplification but i'm studying a lot!!!!i have a problem and i would like a little help if you can!i'm trying to make a single end with a 12ax7 in preamp and a el84 in power amp!a have bought from my fault a toroidal power trans that has output on secondary 240V without center tap so with full wave rectifier bridge this could be about 350V(am i right?)but i have a schematic that the power trans is the hammond 369EX(190-0-190)so i would like to help with the power circuit.the photo is the original schematic with the hammond!!!could i have the same stage voltages with my transformer???and if someone could help me...what resistors and caps values i would use to have the same voltages?plz help

[Satamax]

240x1.4 =336vdc. That's theory.

See what PSUD has to say.

PSUD2

[snakepit]

yeah i know this theory!do you believe that i can reduce that voltage to approach about 250-260V???i also have this software but i can't make it have an output of the stages that the schematic shows!!thnx for you reply!!!

[Satamax]

Best advice i can give, make a temporary power supply. You rig up your trany, bridge recto, big cap, and see what you get out of that. Remember that under load, voltage might drop 15 to 20v. But with 240, you will never get 260vdc. May be you'd drop to 315. IIRC the zener trick is useable on a bridge recto. The - leg of teh bridge recto being pretty much like a centertap. If ever you have a 5V tap on your trany, rig up a tube type rectifier for the two + legs of teh bridge recto, that would drop some voltage.

[snakepit]

thnx a lot satamax....i'll begin with 4 220uf 450V and i will see!!!with about 315 as you say under load and the "zener trick" i think it'll be ok!!!thnx and i'll keep you informed!!thnx again!!!