Humming Looper

[Jack Collins]

I'm trying to build a 4 loop looper based on Aron's diagram:

http://www.diystompboxes.com/tbbox/tbbox.jpg

daisy chaining 4 of these together.  I connected the grounds on all the input and output jacks together.  The signal comes in through the input jack, connects to the input of the first switch, goes out the output of the same switch then on to the input of the next switch etc.  Finally to the
output jack.

I plan to wire up indicator lights but haven't done so yet.

I tore the guts out of a broken reverb pan and used the case to house it all.

It switches and passes signal but hums like a mother.  I though that the
metal of the pan would do a good job of shielding it.  

I'm thinking that the answer is to use shielded cable for all the signal carrying wire.  Grounding the shield at one end to the pan.  Is there something simpler that I am missing?

Thanks in advance for any help.

[jasonober]

http://www.singlecoil.com/tb-strip/tbstrip.html

[jasonober]

http://www.singlecoil.com/tb-strip/tbstrip.html

I used this design have had no humming or noise 12 loop in a hammond #? box