Quick Shielded Cable Question

[jacobyjd]

Hey, the search button didn't really lend me a definitive answer--sorry if this is a repeat due to weak search-fu:

I'm building a BSIAB2 combined with a TS and some sort of booster in a 1790 enclosure, meaning I'll be dealing with wire runs of up to 5 inches (from the stomp switch to the jacks). I know the BS can be a bit of a troublemaker when it comes to noise, so I was wondering if I will be alright running shielded cable from the jacks to the switch, then from the switch to the effect in/out, or if I should use shielded cable for all the pot leads as well...or...can I get away with no shielded cable?

I'm using a grounded bypass as well, just fyi.

*EDIT* Just realized I forgot to mention that with the offboard component layout scheme i'll be using, there'll be no need for the input/output wires to cross--the closest they'll ever get is at the footswitch.

Thanks,

-Josh

[John Lyons]

I'd use shielded wire on anything over a couple inches long.
Mainly the input to the switch and the switch to the input of the board.
The output as well but not as important as the input.
You have to figure that the input will pick up and noise and amplifiy the poop out of it
with the BSIAB. 

john

[jacobyjd]

Ok, thanks John--that's what I was thinking, but I've never build a BSIAB before, so I couldn't be sure. Now I just have to wait for my enclosure to get here...

[96ecss]

FWIW, I've built 4 BSIAB2's without shielded cable and never had a noise problem. But having said that, shielded wire is probably a good idea since you're running longer lengths than I did.

Dave

[earthtonesaudio]

Also if you can locate the boards close to the input jack and switch, that's better.  High gain, long leads, and high impedance are all working against you on this one.

[jacobyjd]

Also if you can locate the boards close to the input jack and switch, that's better.  High gain, long leads, and high impedance are all working against you on this one.

Absolutely--like I mentioned, it's going into a large enclosure with some other goodies (all working independently of each other), so the board will go between the switch and the jacks, but I'll try to cheat the board as close to the switch as possible--the distance from the jacks to the switch is something I can't really shorten.

I was taking some stock of what I've got lying around, and I think I'll have enough shielded cable to use on all the input/output leads, just to be safe.

Thx for the suggestions!

[Paul Perry (Frostwave)]

Whether shielding will help depends on what the source of noise is.
If it is an amplified hiss caused by inherent transistor noise being amplified, then shielding won't help.
If it is noise from external interference, then shielding might help.
If there are oscillations and instability due to accidental feedback via coupling via random wiring to the switch and inputs and output, then yes, shielding is essential.