Reassembling this amplifier and looking at the schematic I'm questioning the lack of large aluminum electrolytic in the output (quasi-complementary?)? I've seen pictures of amps and some have a 1000uF/50V in series with the output terminals. Also this amp has an extra large hole in the back panel for an isolating fiber washer(s) for the output jack but NOT for the extension speaker jack?? Doesn't this defeat the isolation?