[sdiy] should I connect the plug ground to the transformer ground?

[media at mail1.nai.net]

>> Last couple of Power supply's I build I just attached the plug ground to
>>>> the transformer chassis, but the one I have now doesn't have one,

It doesn't have a chassis??

>> so do I leave it floating or should I connect it to the 0V output of the
>> secondary?

Since no one else answered this, I would not connect the "plug ground" to
the common of the secondary -- I can't imagine how it could help anything,
and it may cause a ground loop or other problems.

>this thread could get big.... i know every time i get a new [used] synth,
>if it hums, i open it up, and cut the green wire, of the AC.

The reason why your new synths are humming, and you end up cutting the
earth every time, is because you did it the first time.  While the key to
avoiding ground loops is consistency, floating the mains is a foolish
consistency.  It is a last resort that should only be done in the heat of
battle.  You should reconnect the green wires, and find a less dangerous
solution to your problem.  By eliminating the earth grounds you are raising
your noise floor and tempting fate.