(50K trimmers are used instead of fixed 33K resistors to adjust the correct Drain voltages of each FET or for your own tuning.)

What affect does this due to the circuit? and how does it change the sound of the pre-amp? more gain?

I have an old rg100es and looking to do a few simple mods with it.I am wondering if changing the fixed resistors to trim pots will help me get different tones/gain.

thank you!