Play it where it sounds the best.
Well - most likely a cartridge that is designed for a 47KOhm load and 40dB gain cannot sound good into a 20 Ohm load and 66dB gain.
The Shindo MC input really only works well with a handful of cartridges (Shindo SPU and Miyabi).
Good catch, Restock. The review says that "it CAN be used with MM..." My interpretation is that one does not have MC, he can use MM. But let me try it with MM and I will let you know how it does.
That usually means you could use it into a MC input with a gain of say 55dB and a loading in the several KOhm range. In this case the 20 Ohm load of the Shindo could almost damage the cartridge as this is way below the internal impedance of the Blackbird (which is 180 Ohm). It should sound worlds better with the MM input.

