The best loading for an MC cartridge is system dependent, and somewhat taste dependent also. It will do no harm to try any load from 100 ohms up to 47Kohms. Use familiar recordings with a full range of frequencies, like full orchestra or a classical piano piece that's dynamic and uses the entire keyboard. (Beethoven, not Debussy.) As you move to higher impedances you'll hear more weight behind the HF's and less weight behind the LF's. Lower impedances have the opposite effect. Find the setting where all frequencies seem equally weighted.
BTW, make sure your VTF and especially VTA are spot on for the record you're listening too before messing with different loads. Until you know a system really well it's easy to confuse wrong VTA with wrong loading.
The good news is, changing loads when running directly into a gain stage makes relatively subtle differences compared to load changes when using steput trannies. Pcosta's comment about loads of 4-7 or 30-40 ohms with the Dynavector stepup is not directly relevant to your question. Loading for an MC when running through a stepup is always different (lower) than when running directly into a gain stage.
BTW, make sure your VTF and especially VTA are spot on for the record you're listening too before messing with different loads. Until you know a system really well it's easy to confuse wrong VTA with wrong loading.
The good news is, changing loads when running directly into a gain stage makes relatively subtle differences compared to load changes when using steput trannies. Pcosta's comment about loads of 4-7 or 30-40 ohms with the Dynavector stepup is not directly relevant to your question. Loading for an MC when running through a stepup is always different (lower) than when running directly into a gain stage.