Death metal/hardcorey band i recorded.

The guitars are a little grainy and lacking high end shimmer... It has this fizzy character that I'm not digging.

Is it a Dual Rectifier?

Its isnt, its a 6505, the chain was simply tubescreamer, surpresser 6505 marshall 1960's cab, sm57. I know exactly what you mean though, its doing my nut in!

Tryed to ease off the low pass filter and i keep getting horrendous fizz!

Not much i can do as these were just miced takes, no clean tracks for re amps.

Hmmmmmm.