Help with Sony 777 SACD


I have a Sony 777 and am wondering what the switch on the back of the unit that allows the user to unscrew a plate on the back and swich from standard to a custom setting. Is this a benefit to the sound quality and is there any danger of harming your system?
rivercitylad
The consensus says it sounds better on custom. I have tried both and can not notice any difference but, keep it on custom anyway. "Standard" is supposed to roll off the very high frequencies, "Custom" does not. No reports of any damage have been experienced by anyone using custom.
I find "custom" lets too much garbage into your system, makes the sound less firmed-up. Highs are better, but bass is thinner. I'd try it both ways, no harm is likely, but I think the standard position is best in most systems.
The Custom setting is better in my system. Better space/dimensionality, microdetail and imaging.