If you open it up - all those little screws - towards the rear of the amplifier, kind of right-center, there is a very small, white dip switch that is labeled MM/MC. There are two switches on it, both of which have to be moved to MC.
I had one that I used with an Audio Technica OC-9, and it did not have enough gain to match the CD input, and I ultimately wound up using an outboard phono pre, which also sounded better regardless of gain or volume. Nice amplifier otherwise.
