TubeNet

pauvog1 wrote:Or you could compare the pt 15 and 45slz as they might be more common

A while ago I tried both of these side by side and found the 45slz quite a bit darker sounding - in fact darker than the 2040/5 Eb I had at the time. For me the PT-15 has a more characteristic F tone, but that is just my personal preference.

BTW I tried using a PT-65 mouthpiece in each

Sorry, I did not check the intonation of the 45slz, so really cannot comment. Obviously I have since bought a PT-15 and find that has excellent intonation.