• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Twist dc filament wire?


2007-12-17 2:03 am
twist dc filament wire?

I am using a 12V regulator for my filaments and was wondering if there is any advantage to twisting these wires together? For neatness reasons I would like to twist them and if there is no advantage, the next question is: Is there any harm in twisting them?

I also have a 10" inch run from my fuse to switch, and a 10 inch run back from the switch to where I will be connecting my primaries ( bad layout I know, but I have so much invested at this point I do not want to change it ) should these two wires be twisted?




Paid Member
2007-07-17 2:35 am
Central Berlin, Germany
General rules:

DC lines: not important, but it does not harm, so go ahead.

AC lines: twist with the corresponding return wire (which carries the same current in the opposite direction), even if you get longer runs in total. The loop area is the important thing, should be as small as possible. And keep it away from the signal electronics (run it along the chassis' edges).

- Klaus
Running cables close to the metal shell/chassi/box gives a certain amount of shielding. Running cables along corners in the metal housing helps yet more.
Try to run cables in an XY-fashion where cables carrying "delicate" signals "meet" dirty cables at perfect 90 degrees - not run them parallell.

When layouting the chassi, it's advisable to keep the two channels at one end and the PSU in the other, even it may be more aesthical to have the PSU in the middle flanked by the two channels.