Heater wires through shielded cable

[fossilshark]

Would it be better to run your filament wires through shielded cable than to just twist them? Does anybody do this?

[FranciscoPerez]

It's been done before, but not worth the hassle imo...
Elevating the heater supply and using dc heaters in the first preamp stages is a better refinement, i believe.
Never had an issue  when twisting filament wires in this way, even in very high gain designs:

[hesamadman]

I wouldn't say "better" but maybe you like the install better. With the twisted pair, the two phases kind of cancel each other out. High current can induce noise into other wires. So with the twisted pair, you are reducing the amount of possible induction. With two conductor shielded, nothing is reduced, it is only hoped that the grounded shield will be what takes all of that induction. And it should. But it doesn't mean it will. I think the best thing to do is to lower the amount of possible induction rather than shield the induction. If any of that makes sense.


I have not done dual conductor shielded but have heard from others that it is not worth the trouble and not any more positive with results.

[kagliostro]

My opinion is ......... + 1 for FranciscoPerez

not that I don't agree with hesamadman, but I was thinking exactly what FranciscoPerez said

Franco

[dennyg]

+2 on DC for the pre-amp heaters - a bridge and 10mf cap is less than $5 and you'll get negligible pre-amp hum.  I did this on my latest  build and worked so well I added to previous builds.  They all use a CF so I connect the neg side to an elevated DC reference.  Not sure if it helps with hum tho.  I do twist the wires anyway - not sure if it helps but it's neater.  I also tried regulating and while it creates a flat-line voltage source, there was little noticeable audible hum benefit vs simply DC (which does retain about 200mv ripple on the positive side) - but i do sleep better having such a pure heater source :)