De-Lite grounding

[Puffin]

I have built a De-Lite using the IXYS 20N Dep fets. I have made a sort of star grd on the module where the Power grd, speaker and input grd are connected together. Should I be getting hum? It sounds like 50/60Hz.

 

[Zen Mod]

more info , please

pics

 

[Puffin]

More info about what?

All grds are tied together in one place.

 

[underwurlde]

Tried connecting the mains earth connection to your GND?

 

[Puffin]

I was just tryong to edit my post to say that at present the mains safety earth is not connected. I was under the impression that connencting mains earth to 0v might cause more problems?

 

[underwurlde]

try it...

 

[Puffin]

I will

 

[cochleus]

Ground lines coming from a star can pick up xformer buzz. Try moving the wires to a different location if you can.

 

[Puffin]

try it...

Tried that - no difference

 

[Puffin]

Ground lines coming from a star can pick up xformer buzz. Try moving the wires to a different location if you can.

Space is tight. Where should they be moved to?

 

[underwurlde]

Hmmm, intriguing!

Can you post up a piccy of what you've come up with so far?

Also, is your circuit in a metal box (and is this earthed)?

Andy

 

[cochleus]

Just as long as the wire isn't passing too close to the xformer magnetic field. In my case it was only a matter of about one inch farther away from xformer. I have an F2J clone.

 

[Puffin]

I am posting a pic as I might have had that "illuminating" moment as you do when you think hard.

I originally had the tx at the rear of the case. The bridges are attached to the rear panel. To free up more space I moved it to the front (see pic). The tx secondary wirings are running back to the bridges along the side of the case, under the power amp modules. Could this be causing the problem?

An externally hosted image should be here but it was not working when we last tested it.

 

[cochleus]

My guess is that it is the tx by induction into the input ground.

 

[Puffin]

My guess is that it is the tx by induction into the input ground.

Any suggestions as to how to cure it?

 

[cochleus]

I remember one guy inserting a metal (steel?) plate between the tx and circuits that solved same problem.

 

[underwurlde]

^ second that. Also, are your audio input cables not screened? Looks like 2 individual wires, but I could be wrong...

 

[AudioSan]

it sounds like a ground loop. is it humming with and without a source connected?

 

[underwurlde]

...or does it still hum if both the L & R channel input connections are shorted to their GND connections at the input connection?

 

[underwurlde]

http://www.diyaudio.com/forums/diya...udio-component-grounding-interconnection.html