I'm going to get a jcm800 2203 from nik at ceriatone with PPIMV mod in the pack2+JJ El34 tubes+ head cab package deal. I am fairly confident with the soldering and building of the amp and my father is trained in using a soldering iron as part of his job teaching welding and fitting ect... But the only thing I am unsure of is biasing and setting the new amp up.
If i was retubing say a second hand amp with the exact same tubes or doing a bias check on an old amp i would be probably right. It's just setting up and testing a new amp isn't as easy as retubing.

Could someone explain this in simple idiots form. Lol... I understand how to work out what Ma to set poweramp tubes at you need to divide tube dissipation by the plate voltage and that give you 100% and as tubes run best at about 70% you divide by .7
So say that plate voltage was 470 and the EL34's tube dissipation is 25watts it would be 25 devide by 470 = 53Ma then times by .7 which = 37Ma.
My questions are:

how do you work out/measure plate voltage?

dose nik's ceriatone jcm 800 2203 have a bias trim pot that ajust all vavles and if so were is it located using nik's jcm800 diagrahm?

Are pre-amp tubes self biasing if not how do you bias these?

many thanks in advance!!!!!!!!

P.s. this will be my first build
 

Thanks, i will do that (go ask what Ma they have there el34's at)
Before posting my last question i read heaps and heaps on biasing buy not one information said how to work out plate voltage.
the power in our county is 240volts would that have a differences as to what Ma i set the valves at?

thanks