Fender Twin Reverb (1971) Reverb noise/Power tube recommedations?

[wthiessen]

Hi,

1.) I'm having a problem with the reverb on my 71 Fender Twin Reverb.
When it's on I hear a lot of noise, it almost sounds like there's an electrical storm going on in my amp. It's not really loud, but loud enough to cause concern and be annoying.
I tinker with this amp a lot, and wonder if I may have done something to cause this.
I tried changed the reverb driver tube (AT7), but it still does it.
Can someone help me out with this?

2.) Does it matter if I have Sovtek 6L6WXT's on side, and 5881WXT's on the other side?

3.) Can anyone recommend the best tubes for this amp? I read that JJ tubes are the best, but that was from the reseller.

Thanks!
Will