I have a NAD 533 with a Goldring Elektra cartridge & stylus. Sound in the left channel is very low, sound in the right channel is normal. It's not the amp, I have swapped the turntable over and that one works as normal. What would cause this, and what should I be looking at? If I record the sound onto my computer I can normalise both channels independently and they sound more or less OK if a bit distorted in the left channel, but then obviously the vinyl noise is also amplified on that side.