Tube Pre Amp or Tube Phono stage

Hello FriendsI have put this question, to this site before??, But did not received, the answers??I have, a solid phono stage , a JLTI , what I like about it is I can inset RCA Cartridge loading plugs, that is a good option??Howe ever, the Pre amp, and phono stage, are all solid state, I wish I can retain the bass, but shave a bit of the top, which sounds a bit edgy!!For best results, should I replace the phono stage, with Tubes, or keep the solid state Pre amp??I want a deep bass?? with sweet highs??My Phono amp is a JLTI, solid stage, with cartridge loading via RCA plug's at the rear, I'm running a Zu/Dennon 103 cartridge, It has a cartridge loading at 300 ohms, I have both RCA plug's at that loading, but it sounds bright!!I have replaced one RCA plug, rated  at 250 ohms, to try and tame things down, if I wan't more bass, Should I inserted, the 300 ohm in the red out put, or the other way around??Which comes back to my original question, for better bass, and nice highs!!Tube phono stage, or Tube pramp??Friends, I live on the far south coast of Australia, the nearest hi Fi shop, is three hours drive away!!Can some one put me on the right pathMany ThanksDavidAustralia