unwanted buzz......

I recently wired some new pickups into a guitar but am finding there is a lot of (a lot more than with my non-project guitar) unwanted buzz when i'm not touching the strings or bridge/tuners etc.

Is this just the amp (crate combo) making things seem worse? as its better in my mates fender deville, or is it more likely to be a problem with my grounding/wires used. It noticably worse on the neck pickup too....

Whilst i'm here,
1. my pots crackle - does this indicate that they're porbably old? - if it does i'll have a bone to pick with an ebayer.....
2. My tone pot is extremely uresponsive for 9/10ths of its motion, and cuts all highs out after that. Do i need to consider a different capacitor? its got a pretty standard 223 in at the moment.....

Cheers for any advice you have.

1. Pots crackle. Bad pots. You could try cleaning them with some Radio Shack tuner cleaner but it would be better to replace them.
2. Could be the cap but more likely either the pot has gone bad (missing carbon on the pad until it hits a good spot) or someone has put the wrong kind of pot (log vs audio or something like that) in it.

Are these humbucker pickups or single/double coil rails?

Both pickups are humbuckers
Bridge is dimarzio dual sound
Neck is an Evans Eliminator 2

I bought the pots on ebay from someone saying they were brand new emg pots, seems i may have been had.....

You want to bin the pots, check out :

http://www.stewmac.com they are fantastic !

Unwanted buzzing could be a few different things.
1. You could have a bad ground.
2. You could have it wired wrong. (Very easy to do)

You see, basically in order to get the noise out of the pickups, they sould be wired out of phase with each other. That meaning one should basically be north, and the other south.
If you did this, check your grounds EVERYWHERE... One ground wire off will give you noise from hell...

Shoot the pot with tuner cleaner. The pot could be brand new, just sitting around collecting dust. Dust makes it scratchy...