Bipolar power supply ground

[riggler]

Hi,

http://www.generalguitargadgets.com/pdf/ggg_bipolar_ps.pdf

I built this bipolar power supply. On the schematic it shows a ground symbol on the 0v output connection. I am not sure if that means circuit ground only, or chassis ground. The transformer physically hums a little bit, and the reverb it is used for has a hum.

So I wanted to know if I should ground the output 0V connection to the chassis. Thanks!

 

[riggler]

Friendly bump...

 

[PRR]

http://www.radioshack.com/product/index.jsp?productId=2062622

 

[Blue Jinn]

OT slightly but does the reverb hum with battery power? Is it a spring type?. Only reason I'm asking is I built a spring reverb a few years ago before I knew better and didn't shield some of the I/O's.

It has a slight hum as well, and I  assumed ground loop or psu, but using an Ebtech hum eliminator, and running it on batteries didn't help the hum.

 

[riggler]

Ha! It is a spring reverb. It's a Multi-Track Dual Equalized spring reverb. I have the external PSU about 3 feet from the unit. Last night I grounded the 0V output to the chassis, with the IEC power ground, no difference. I am going to get a scope so I can learn about what is happening. Is ripple the problem? Is my power transformer too close?

For what it's worth, the unit is unbalanced in / out, the noise floats at about -60dBFS (referenced to -18dBFS at +4, 0VU). Maybe it's fine and this is normal? (Although Orban 111 is nice and queit...)

The one thing I don't like is that the PSU is vibrating, not a lot, but you feel it when you put your hand on it. Ever so slightly warm to the touch.
Reading about stability and things, and I am wondering if I should have built the PSU with a center-tapped transformer.

I tried to build this PSU cleanly:

I also tried shielded cable from the PSU to the unit, didn't change a thing. I have not tried battery power, but good idea! My audio wiring is shielded.

The original power supply for this unit was submerged underwater for about 5 years and is utterly destroyed!