todo:
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 - update slider/buttons when entering (in inactive mode)
 - new "mybutton" style
 - correct slider restricting (pre_handler).
 - very small & very big buttons
 - Menues ?
 - curses interface ?
 - correct THE bug

 _ *** 'turn off' with rec buttons -> no recording !
  
ideas:
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 - support for special Mixer settings
    (Example: AGC for SB)
 - grouping of Channels
 - set stereo channels permanent to mono
 - "FLAT" button (Bass/Treble)
 - save/load button with file selector
