@ditusa and Jason have nailed it. Nothing to do with cart or phono stage. Or acoustic feedback. Or TT isolation!!
15w of Cary fleapower won't drive the the 87dB grossly inefficient Totems. So it sounds fine when underdriven but is probably bleeding out 5% distortion when you up the volume.
Only three solutions:
1. If you like the sound, don't up the volume.
2. Ditch the fleapower Cary if you like the Totems and get an amp giving 200w or so with a decent power supply section.
3. If you like the Cary, get speakers with around 100dB sensitivity. You'll be limited to horns, just like all the other fleapower users.