I've noticed some sound quality issues with my Beogram 3000 when connected to my Beosound 4.  Because the BS4 does not have a phono input, it is connected via a phono stage.  I have two phono stages, one was quite cheap (but useful as it has DIN input) and one more expensive Pro-Ject one.  I've tried both, but I'm getting some poor quality.  I'm no audiophile but it's just not right - it's not separating well and there is some distortion at the top and bottom. I was worried it might be the turntable or the MMC4 (which I recently had re-tipped at some expense), so to test it, I connected it to my Beocenter 8500 instead (which I usually use with a Beogram 8500, in a different room), and connected my Beolab 6000 speakers to that too, so I could do a real comparison.  It sounded so much better - at least I know from this that it is unlikely to be the turntable or cartridge that has the issue - it's got to be the phono stage, the BS4, or the cabling. However, to perform a true test with the Pro-Ject phono stage, I need to ground it.  Can anyone tell me, on the DIN plug, is it the ring that provides the ground?  Or, could I just ground the BG3000 by connecting a wire to one of the two screws on the back (there is one either side, at the back of the lid), leading to the ground on the phono stage?  It may be that the cheaper of my two phono stages is the problem, I'm hoping so anyway!  It does cause a lot of interference and the quality varies if you move the phono stage at all while in use, so I'm guessing it might just be quite poorly built. The Pro-Ject one is already in use on another (non B&O) HiFi in the house but if I can get it connected and grounded via that one, and it sounds good, I'll just buy another the same.