signal wire lengths?

[Enzo]

If I have a filament supply line and a sensitive signal wire, I want them to be at right angles where they cross, so as to reduce any coupling of the 60Hz heater supply into the signal line.

So I doubt I would twist them together.

 

[Speedskater]

Twist the filament supply line conductors together. Route the sensitive signal conductor some distance from the supply line and cross at right angles.

 

[scottjoplin]

If I have a filament supply line and a sensitive signal wire, I want them to be at right angles where they cross, so as to reduce any coupling of the 60Hz heater supply into the signal line.

So I doubt I would twist them together.

Absolutely definitely not

 

[schiirrn]

You don't twist the filament and signal wires together. You twist the filament wires (supply and return) as to reduce the loop area by keeping them close so they don't act as antennas and the twisting helps cancel the stray fields emitted by the filament wiring. The "signal line" should be close to it's return path (small loop area) as to be as little of an antenna as possible.

 

[myleftear]

I once started a thread admiring some oldschool building method (no pub/breadboard), which developed wonderfully. There, a true master was mentioned with a pic of some really clunky piece of gear—dozens of wires wildly through the air, it was said to be a masterpiece for not acting as antennae...
OTOH, somewhere a tube-amp was de-hummed just by untangling twisted wires that shouldn‘t have been twisted together. Lesson=twist what belong together...

 

[lcsaszar]

I often see wonderful builds with best-of-parts (that is, the builders didn't spare anything) but the signal-wires, mostly twisted pairs, going all the way back-to-front from the RCA-plug to the selector-switch (elma 04, seiden, etc.), over to a luscious volume-control of sorts, and from there all the way back to the board.

You don't need to run signal wires back and forth. Place selector switches, volume controls, etc. close to the input/output connectors, and extend the shaft of the controls from the rear of the equipment to the front plate.

 

[myleftear]

You don't need to ... extend the shaft of the controls from the rear of the equipment to the front plate.

Yes, except that sometimes the Lay-out and chassis-size makes it very difficult if not impossible.
And, I was questioning the good of keeping the wires as short as feasible ... (while I agree that the theory is clearly in favor of short circuits (ahem [emoji4], short cables)