I recently converted a Bright 18 Watt TMB Amp to a Darker Bassier Amp that I now can not stop playing on by simple modifications I learned on pedals. Ie Generally Larger Caps = Bassier Tone. I changed the .002uF , .01uf and .0047uf Caps and Bass Pot 1M From This Schematic:-
http://ceriatone.com/images/layoutPic/marshallLayout/18wattTMBceriatone.jpgTo .022 uF Caps and Bass Pot 250K on the Jersey Aaron's Schematic :-
http://www.emailtom.org/schematics/ja_layout_2_0.jpgAnd now Am extremely Happy with the Tone of this Amp. Love Playing it now. Confidence gained from first working and learning on Pedals I have now transfered and used on Amps. Thanks.