How many hours is on the cart? They need anywhere from 50-100 hours to break in, and the sound changes a lot while break in is occurring.
As far as the hum goes, I know the A5 has a built in phono stage, but does it give you any type of adjustments at all? If you do have them, there's a good chance they're inside and you'll have to take the cover off the amp to access them. If you have them, lower the gain and that should reduce or eliminate the noise. If not, you may have to try a different cart.
As far as the hum goes, I know the A5 has a built in phono stage, but does it give you any type of adjustments at all? If you do have them, there's a good chance they're inside and you'll have to take the cover off the amp to access them. If you have them, lower the gain and that should reduce or eliminate the noise. If not, you may have to try a different cart.