After your 70 db phono gain you will be down about .12 volts. It just means you will have to turn the volume up a bit more. Usually, in a pre amp, noise floor is what you will be dealing with as you turn it up a little more. I suggest you turn it up to your normal "max" level without any music playing and then see how much the noise increases as you turn it up. I'm going to guess that you will be about 3 o'clock to get the same "max" volume.
BTW IME you need to more concerned with the recommended load impedence of the new cartridge, not the output voltage. Can you change the input impedence of your MC inputs. My Dynavector's sound stage is dramatically better when I got the "load" down to 30 ohms.
BTW IME you need to more concerned with the recommended load impedence of the new cartridge, not the output voltage. Can you change the input impedence of your MC inputs. My Dynavector's sound stage is dramatically better when I got the "load" down to 30 ohms.