I added output and Input jack plates to my cornish board and got NOISE! help!

[sjaltenb]

Ok so I have had my cornish board hooked up for a long time now and have had some minor noise problems mostly with high gain pedals only. For a long time I simply had my output and input jacks hanging off the back of the board onto the carpet literally. the tip was connected to the signal chain and the sleeve (ground) was simply soldered to the enclosure. So, FINALLY i made some plates to install the jacks onto and  BAM...NOISE!! Lots of it!!

The only explanation I can figure is that now that the jack is physically touching the enclosure, it is creating ground loops. So what type of jacks do I need to order so that I can send all the ground directly to the Star ground so it cannot travel elsewhere?? Im guessing this is the prob...


this is before, the jacks were just laying out....no noise

and now they are just mounted on metal plates like the rest of the pots, etc on my board...shown here for those of you who havent seen it..***note..this is not an updated picture with the jack plates, just a way or explaining how i am mounting my pots/jacks on the board.

[bioroids]

If the problem is the sleeve of the jack touching the enlcosure ground, you should use those plastic jacks. I think Smallbear also sells some plastic isolating mounting washers that could be of use too.

But I'm not sure about that, as you said previously the sleeve of the jacks was soldered to the enclosure... it is no different than touching the enclosure with the jack sleeve.

Regards

Miguel

[sjaltenb]

maybe since it touches over such a large suface area it creates more ground loops?? anyone else? Wouldnt i need to use all plastic jacks since the physical tube of the jack will still touch the mounting plate, even though the washers will protect the nuts?

[slacker]

Using plastic Marshall style jacks would be the easiest way to solve it, if it is a ground loop problem. Or if you want to use metal jacks you could isolate the plate from the enclosure in some way. It looks like you've used foil to shield the enclosure so you could remove it from around the plates so they aren't touching it. Then wire the ground wires from the jacks to your star ground point, the plates themselves will still be grounded though the metal jack so it should work fine.