How do I EM shield my electronics?

This can be a very difficult problem.

The usual issue with AM radio "ingress" (as it's called) is that your cables (speaker wires with the Logitech, instrument cord with the Marshall) are picking up the radio waves.

Sometimes just putting ferrite cores (beads, "donuts") on the cables is enough. You have to get the right ones - there are different types of ferrite for different frequencies.

If that's not enough then you need to replace the cables with better-shielded ones. Speaker wires are usually not shielded at all - replace these with shielded twisted pair. Ground the shield at the amplifier end.

The instrument cord is a pain because guitars (for some unfathomable reason) don't use balanced connections. If they did I'd recommend star quad cable. As it is... try using an instrument cord with double shielding (one braid, one foil).

The guitar itself can be the ingress point as well.

For all equipment, be sure the equipment itself is well grounded. i.e. do not use three-prong to two-prong adapters on your power cords.

The logitech speakers probably run through a "wall wart" with only two prongs and probably don't have a shielded chassis anyway. A better speaker set might be the ony cure here.

If you know any ham radio operators they can usually help with these issues. They will be happy to hear from someone who isn't complaining about *their* transmissions. :) Also, check with other guitar players in your area.

Many of the miltary installations are shielded. Most nukes generate an EMP thats pretty powerful. Why not just use a big *** neutron bomb? You could kill everyone and still have all the stuff to enjoy. Would suck without your nintendo.