Any line level input should work fine.

dbt1969 wrote:

Even though this amp has a phono output could I use one of the other outputs to run a separate phono preamp?

You saying "output" when you mean INPUT! The OUTPUT of the amplifier connects to the speakers.

That amplifier has a pair of PHONO INPUT jacks which allows a phono cartridge to be connected directly to the amplifier.

This is because a phono preamp with an RIAA equalization circuit is included within the amplifier for that purpose.

If you want to use an outboard Phono Preamp/RIAA equalizer, then its output would connect to any available line-level input of the amplifier.

Please look up "RIAA EQUALIZATION" ON Wikipedia to understand why the output of a vinyl record requires equalization as well as additional gain to be listenable.