Shielding, was: Constant buzzing - can it be killed!

[William Walker <billwalker@baymoon.com>]

I have been trouble shooting a noise problem of my own recently that  
has finally been identified, after much consternation that I thought  
I'd share even though it may not be directly applicable to Krispen's  
recent issues. For the past several months I have had an intermittent   
high frequency noise issue that only manifested when I was recording  
1/2 speed loops on the looperlative. I'd record content and get this  
High frequency whine, embedded in my loops that would go away when I  
toggled back to normal speed. My initial thought was it was the LP-1,  
but like I said this wasn't happening all the time and only at home,  
which made wonder if it was something else instead. Today after I got  
home from rehearsal I set my rig back up and started playing and  
looping at half speed and low and behold the whine was back. I first  
tried turning off the computer that wasn't in use thinking perhaps its  
wireless might be the culprit. Nope, The i realized my wife was in the  
other room, nursing a cold and watching TV. last October we switched  
to Direct TV. I asked her to turn off the TV and DTV router, and then  
recorded another loop. The noise did not re-appear!!  Something in the  
router or dish was adding interference, and its at the opposite corner  
of our house. I tried the test twice to make sure.  This has gotten me  
thinking about two things,  Dish TV and microwaves in general might be  
causing others to have noise and interference issues., and that so  
much of the electric gear we use requires wall wart style power  
supplies which are not particularly well shielded and may be potential  
conduits for this type of interference. I've had other interference  
from time to time from neighbors with high speed power tools and a  
sculpture neighbor with an arc welder.  So what to do?, I'm seriously  
considering an isolation transformer and I'm wondering if anyone might  
know if bunching wall warts together might perhaps increase noise  
issues? I've though about building a shielded box to put them all in  
or find some steel army surplus box to stick them in.  I don't know if  
I'm barking up the wrong tree with that idea. I have no electronics  
education to speak of other than knowing not to stick a fork in to a  
wall socket.  I also wonder if its possible to adequately shield wall  
warts?  I'm also investigating which of the new crop of multiple power  
supplies from Voodoo labs Dunlop and T rex might be able to handle the  
higher voltage and milli amps of my rack gear that requires power  
supplies. I have an older pedal power plus from Voodoo that works  
great with my regular pedals. I'd just as soon jettison as many wall  
warts as I can if possible.
  Any suggestions would be much appreciated.
Bill