The DL-103 is a very, very good cartridge. The DL-103R is a great catrridge, IMHO. I have heard the Zu version, and I would say that you should probably plan to upgrade your deck and arm if you want to notice any significant upgrade from the Zu.
If it were me and I wanted a bit more performance from the 103, I would consider a wood body modification from Uwe or one of the other sources. Again, my guess is that you will receive more benefit from the upgrade with a deck/arm combo capable of resolving a bit more detail than your PL-50; which is a good TT but not the final word on detail.
If it were me and I wanted a bit more performance from the 103, I would consider a wood body modification from Uwe or one of the other sources. Again, my guess is that you will receive more benefit from the upgrade with a deck/arm combo capable of resolving a bit more detail than your PL-50; which is a good TT but not the final word on detail.