Hi all, just bought a new Cambridge Audio 640p phono preamp today to sit between my Nad C352 amp and Aiwa PX-E800 turntable. When all assembled correctly, I get a horrendous noise coming out of the speakers, extremely loud and distorted. There is some noise there even when the turntable is not operating. I've been using the turntable up to now just plugged into one of the spare channels on the amp and though not as loud as the other channels, has been fine sound-wise. I've read something about the need to ground the turntable, but there's no grounding lead apparent and if this was the problem, why had it not surfaced before? Any suggestions gratefully received! Cheers, Tom