Question: shielded wire in stompboxes

[moritz]

I'm just in the middle of building a fuzz face and i'm wondering about using shielded wire on the inside of the stompbox.

Does this have any use in terms of building a quiet unit, or is it just useless over-engineering? I mean, there's so many bare wires showing on the perfboard itself, and the input/output jacks are bare -would it really make a difference if the wire used for all the inter-connections (between pots, jacks, PCB, etc) was shielded or not (mind you, i'm making these connections as short as possible)?

Also, in terms of twisting/bunching up groups of wires with cable ties for neatness sake, are there certain groups of wires which i should avoid bunching together (say, those carrying input power and those carrying audio signals) or does it not make a difference whatsoever?

cheers.

[Arn C.]

Morebeer,
    I personally use shielded wire in every effect I build.  I buy those cheap rca to rca cables and cut off the ends.   I put one wire from each jack to my stomp switch.  I use the shield and ground it to the jack ground ad the other end don't use the shielding at all.  Just the center lead.   My pedals are rarely noisy.

But, as some have said here, that if its in a metal box, there is no need for the shielded wire, since the metal box is the shielding.

I guess it is up to you!

Peace!
Arn C.

[audioguy]

are there certain groups of wires which i should avoid bunching together (say, those carrying input power and those carrying audio signals) or does it not make a difference whatsoever?

This is something I've been wondering myself

[Ansil]

when i was doing switching systems for pro rack gear we were always talk to keep audio and voltage signals at 90 degrees from each other even if it was ridiculously shielded.  thats how i try to keep my pedals if they cross they do so at right angles  only had two things that had hum i couldn't figure out why. and they both cleared up with replacement transformers.  so if its hyped up mumbo jumbo i will continue to do it so i can sleep at night. if its really effective outside the theorized world i will have been doing it anyway is my philosophy :wink:

[audioguy]

I can see it on big rack rigs with alot of voltage and signal running, but in these boxes with their power draw its really hard to imagine.
I keep my lines so short I physically cant run them any other way than a straight line to their connect point.
I just rebuilt a Muff Fuzz- outside of a box it was nasty noisy (computer monitor and the like) - put into an enclosure and it quieted right up.

[Lonestarjohnny]

To Each his own on this subject, what ever work's best, I use shielded on my pedal's, not on every wire, but just off board run's, and yes, and I do attach only 1 end of the shield, normally at the pot and jack's,
Johnny

[Peter Snowberg]

For low level/high impedance runs in the proximity of high level/low impedance runs, it's hard to argue against using coax. In most pedals it won't matter, but I always use RG-174 in high impedance situations. Most of the time this means the input lead only on a high gain boost or effect.

[Paul Marossy]

The only place where I use shielded cable is in tube based pedals, mainly because there is AC running around inside of them for the tube heaters...

[LinuxMan]

Heh,

I just happened to pull this one out while doing a search on another subject: click

Talking about coincidence ....

Cheers
LM

[Paul Perry (Frostwave)]

The only place where I use shielded cable is in tube based pedals, mainly because there is AC running around inside of them for the tube heaters...

..you prob know this, but in case anyone doesn't, you can cut down interference radiation froim heater wiring by twisting the two wires together along its run. This cancels out the radiated field pretty well, when you look in old tube gear & see twisted heater wiring, it isn't just some neatness fetish.

[moritz]

Thanks everyone for your input... this forum is such a well of wisdom.  :wink:

Anyway, i've come up with an idea... Now i'm not too experienced with electronics, so this may be somewhat ridiculous, but in terms of isolating power and audio signal flows, would it be useful to use normal wire for all the audio signal runs and only use shielded for power runs (this would make wiring the thing a lot easier, as the chunky shielded wire is kinda difficult to work with)?

Is this a viable solution or not?  :?

[Paul Marossy]

Yeah, I always twist my heater wiring for that very reason. And it also looks neater, too. In the case of my McTube, though, there are two back to back transformers inside of the enclosure, so how that is laid out can matter. Shielded cable, IMO, isn't really necessary most of the time, but it certainly can't hurt anything. This is just based on my on experience. With the exception of the Shaka Tube, I haven't had any high gain distortion pedals give me the sorts of problems that would require shielded cables. YMMV.