Ron -

I had the same concern about the ZP3 voltage.  However, Steve clarified the issue by saying that the cartridge voltage was the main item to consider.  I was looking at the Ortofon 2M Blue MM cartridge.  The voltage specs are > than the 1.0 v or 2.5 v required for the MT or SE34I.

Ortofon 2M Blue Phono Cartridge Specifications
- Output voltage @ 1kHz: 5.5mV