Shielded input cable

[Rob11966]

Hi all,

I have designed my amp so that the input jack is at the back of the chassis but I need to run the input to the front of the amp (internally). Should I use shielded cable or does it not matter?

As an aside, for anyone who has been following my very slow progress, my chassis arrived from the metal shop a couple of days ago. I must admit the fabricators (although terminally slow) have done a very good job and copied my plans exactly. It is extremely robust. I now know that 3mm aluminum is actually quite solid, it is perhaps a little over engineered! I will post a couple of photo's in the next day or two.

Cheers,

Rob

[HollowState]

Hi Rob,
I would tend to use good quality shielded cable just because it is correct and proper design. Sometimes I make my own with a length of teflon/silver wire inside a piece of braid.

You could also try twisting two pieces of hook-up wire together, using one as a ground, and run it along close to the chassis keeping it away from AC power/filament lines. In either case, if you must cross an AC line, keep the wire intersection at 90º to minimize hum pick up.

Both of these procedures will add a tiny bit of capacitance to the input, but should not cause noticable rolloff if kept as short as possible.

Looking forward to any pictures.

Victor

[Rob11966]

Tanks Victor,
Shielded it is.
Cheers,
Rob