I had predrilled enclosure for an old project and booster board ready, so I was forced to build 3 knob version with led and dc jack
Except range control and boost volume, you have bias - full clockwise is "standard" voltage, that you can lower. The difference is sublte, but changes the feel indeed - from open to more compressed/fatter signal.
No corners cut, including NOS black glass OC43.
$olded