Skip to main content

Annoying Shocks, Ground Loops and Monitors..etc

Ok here we go.. I've had this issue for awhile now and I'm finally getting super annoyed with it.

I have a desk with a built in rack. The only pieces I use are my Furman power conditioner, PreSonus fire studio project and an Alesis RA-150 Amplifier for my monitors. Almost anytime i want to plugin my headphones I have to touch the connector to something metal first (i can hear an audible shock) before i plug it in to the headphone jack of the PreSonus. If I don't do this.. the PreSonus will get a shock or something and the LED clip lights will all go off. I then have to turn off the unit and restart it.

How can I avoid this. Is having a rug causing this?

There is also a slight hum if i crank the gain knobs of the headphones or monitor output of the PreSonus.

Do I have a ground loop somewhere?

Comments

Boswell Fri, 01/23/2015 - 11:10

It's you that's getting charged up and not the equipment. My guess is that your chair seat cover is made of a material that when you rub over it wearing trousers, you generate a static potential. This potential causes a discharge whenever something metallic you are in contact with (the headphones in this case) touches earthed metal. The solution is to take your trousers off before mixing.

Unfortunately, I don't have an equally simple solution for the hum problem. Do you get hum if you detatch all the input connections to the Presonus box (except mains) and just have the headphones plugged into it? If so, it indicates a problem inside the box. If not, then a ground loop is more likely.

paulears Fri, 01/23/2015 - 15:08

I have a habit of sitting in the office chair and wheeling myself around, and the static pop when I touch ground is very annoying - in my case it's my chair is insulated from ground, but my feet on the carpet charge me up - often to many thousands of volts!

The low level hum could be a ground loop, or it could simply be poor screening somewhere and maybe you have some poor shielding somewhere.

Curing ground loops is a case of disconnecting everything and re-connecting in sequence. So connect the power amp to the speakers, and hopefully all is quiet, then connect the mixer, then all the other bits, and at some stage the hum will start - that's where you then need to investigate.

John Alexander Sun, 03/08/2015 - 07:53

edaub1, post: 424136, member: 37285 wrote: Ok here we go.. I've had this issue for awhile now and I'm finally getting super annoyed with it.

I have a desk with a built in rack. The only pieces I use are my Furman power conditioner, presonus fire studio project and an Alesis RA-150 Amplifier for my monitors. Almost anytime i want to plug in my headphones I have to touch the connector to something metal first (i can hear an audible shock) before i plug it in to the headphone jack of the Presonus. If I don't do this.. the Presonus will get a shock or something and the LED clip lights will all go off. I then have to turn off the unit and restart it.

How can I avoid this. Is having a rug causing this?

There is also a slight hum if i crank the gain knobs of the headphones or monitor output of the Presonus.

Do I have a ground loop somewhere?

For the shocks, use an antistatic wristband. Follow the directions exactly. If you have to move across a room a lot, it can be a pain, but it cuts down on the swearing from getting a nasty static shock. Also, wearing 100% cotton helps as well. Ground loops, as the last poster pointed out, require you to be a detective. Good luck on both.

x

Register