Re: Keilwerth tone rings
The soldered on tone rings are supposed to mimic the rolled tone holes that the earlier Conn horns had and give a similar sound. there are advantages and disadvantages to the rolled tone holes. Theoretically, the pads should last longer on a horn with tone rings or rolled tone holes because the rings/rolled tone holes provide a thicker lip and seating surface around the tone holes, and the tone holes are less apt to cut into the pads. The general concensous with the tone rings though is that the disadvantages out-way the advantages; there isn't a big difference in the sound, and getting the pads to seat properly can be difficult. My recommendation would be the SX-90. They're a GREAT horn! I'm sure you would be very satisfied with it.