EL34/12AX7 PP Amplifier Board build.

[Ken-Mutzabaugh]

I am starting this board with a lot of thanks to this site. I will post my progress and of course will be asking questions along the way! I love this group and how informative it is.
My first question is the wiring for 6.3v on schematic it shows it gets run from tube to tube with wire. But no one else seems to have done that in their builds? See picture.

[cool]

Hi Ken, welcome. I see you placed 2 resistors at the fuse places. Later they will be replaced i believe? The filament wire is ok, only you should better twist those wires preventing hum radiation. Good luck with the project!

[Ken-Mutzabaugh]

Hello thanks for allowing me to post and the greetings!
What two resistors do you mean? I so far been going off data sheet and pictures of other builds?
And with the wires going to 6.3v on top side of board is ok?
Only asking because I have not seen it on any other build using same board?
Waiting on parts will update as I go along. Any input on type of power transformer and out put transformer as well as inducter? Thanks!

[cool]

I dont have the schematic but normally F stands for Fuse on a pcb. The 2 places i saw have names F10.
But maybe i see it wrong.

[Ken-Mutzabaugh]

Well I seen two types of resistors used in those positions on two separate boards. See attached photo.
I wished I had a manual for putting this together. Just as a go to if I run into trouble.

[Henkjan]

Hi Ken, welcome to the forum

[Barry2001]

Welcome here Ken. We have an introduction place on this forum, if you want you can do a short introduction of yourself there.

Maybe the filament wiring is done deliberately external from the board so you can make it DC if you want.

If you keep it AC directly from the transformer the advise is to keep the wires away from the signal path, and twist them tightly like Cool already mentioned. Or just try it, to see if it produces hum that way.

[douwebakker]

Ook welkom Ken.

[Ken-Mutzabaugh]

Thankyou audio friends. This is a great forum and I love the info that is related here. I hope I am able to provide insight as well and provide updates as I go along with this build. I will go in an introduce my self. I’m still figuring this forum out.
For an update on build I received some resistors etc. today and filled the board up, Still waiting on a few other things as well as have to order some things yet.
It seems like there is A LOT of difference between diagram and what’s on the board. I am hoping that my best guesses are correct as I have been going off paperwork instead of what is on board for the most part. I attached some images as well. Thanks everyone!

[Ken-Mutzabaugh]

This is the diagram I have been going off instead of the board. As well as the BOM list. Many differences in resistor values between board and diagram. Fingers crossed diagram and BOM list is correct, I also ordered (4) 20k Trimmer pots instead of 22K and installed them. I got confused because board said 20k and directions had 22k. I don’t think it would make a big difference? Any input? Thanks everyone for greetings!

[peterl]

Hi Ken, welcome, the 4x 20K trimmer pot that doesn't make a difference.

[reinaard]

Hi Ken here the schematics and foto’s from the same amp.