I have gotten an imense help from input gathered at litening meets. Both my own observations and from other participants. Discussion face to face with a shared listening experience is not available anywhere else.

Actually seeing how another circuit sounds is another bit of input. Seperating the small details from gross circuit changes is difficult. If it were easy, everybody would be doing it.

On large coupling caps, how big are they to cause you 'problems'? I like to use big ones in between stages. Moror-run Oilers of 1-2 uF. The current fav is a 1.5 uF MKV rated at 660vac. I got them on ebay for 30 cents each, delivered.
regards,
Douglas