First posting in 12 years

Hi all, I`ve been reading posts , buying and selling on Audiogon for 12 years and this is my first posting because I really need help. I bought a Forte model 40 pre a little while back and the seller told me the person he bought it from replaced the capacitors. Using it in rotation with 3 sets of speakers I`m noticing it`s very bass heavy. Perhaps he used oversized caps? I don`t know. I looked everywhere for a schematic with no luck. I hear Jon Soderberg doesn`t do repairs anymore. Any thoughts? Thanks, tominredbank