Hello I have a Beocord 2000 de luxe K model and it plays really well however when I try to record onto tape through the mic channel the playback is really quiet and muffled. I think the capacitors may need replacing on the recording pre amp board but I don't have the schematic diagram (it's not inside the unit) or a service manual Am I right in thinking that the heads are from left to right: erase head, playback head playback head record head. Would anybody be able to tell me which of the 8 circuit boards is the recording board where I might need to replace the capacitors? I used a multimeter to test resistance on the heads and got readings on all 4 so I am assuming the Bogen recording head hasn't failed. Thanks Jeremy