I am brand new here. Just picked up a nice old '79 2204. It has had some type of seemingly simple gain mod done and the OT replaced. Sounds awesome but for curiosity sake wondering if anyone can give me an idea of the mod, the modder (signature/initials on the board) and what the OT is (labels removed - only info is what's in the pic). I have my suspicions on the OT but am clueless as to mod/modder. Any thoughts much appreciated - thanks!