I have 3 Strats that have the old "loss of treble" problem when you roll down the volume control. What is an effective way to remedy this? They all have "standard" Strat wiring. 2 of them have 2 Texas Specials and a Dimarzio PAF at the bridge and the other has 2 American Standard singles and a Dimarzio PAF at the bridge, they all have 250k pots also.