Details will help here. How much gain does the phono stage have? What is the output of your MC (not clear if it is HOMC or LOMC from your post)? Do you have this gain problem with any non-phono input?
You could also buy an external phono stage that can provide the gain you need if you don't want to cahnge carts or get into SUTs.
You could also buy an external phono stage that can provide the gain you need if you don't want to cahnge carts or get into SUTs.