I bought a tube amp mono block,and I can't find any info on it on the web.I would like to get my hands on a copy of the schematic to work on it,Its a B/A HI/FI model BA-20-4,tubes are 2-12AX7,2-6BQ5,1-Z80.Controls are Contour,Loudness,Bass,Treble"on/off",5 way input selector.I know its not worth much,but I always wanted to restore a 6BQ5 push/pull,I am tired of playing with 6V6's.