i have a ge 5751 black plate, which i use in an audionote cd player. it's my favorite tube, for reasons opposite to those stated above, namely it significantly rolls off the treble, adds a touch of veiling and takes the edge off most poorly recorded discs.
another great tube is a ge 5814 black plate. i have often substituted this tube for a 12ax7 in preamps or cd players.
you might also consider a 12ay7 as well.
another great tube is a ge 5814 black plate. i have often substituted this tube for a 12ax7 in preamps or cd players.
you might also consider a 12ay7 as well.