The preamp is responsible for taking the relatively puny signal from an electric guitar, adding muscle to it, determining how clean, crunchy, or highly overdriven it is before it hits the power amp stage, and also shaping its basic tonality using the Treble, Middle, and Bass controls.
https://www.sweetwater.com/insync/guitarists-guide-electric-guitar-amps-part-2/
I know I go on (and on and on) about preamps and gain staging.
If you have tone "issues" and you havn't yet spent some time on either of these interrelated topics, you really will be doing yourself a huge favour by investing some reading/youtubing time ?
Evern if you use VST plugins, cheap-o multi-fx or high end stuff - this topic and some experimentation will help your tone...I promise ?
