Ground Problem

[Roger Heroux]

I have an active Carvin LB75. When I installed the pre-amp I grounded to the shielding. Now when I remove my fingers from the strings I get a hum/buzz sound. Should I have gounded to the jack input? Also I grounded in two spots on the shielding. Any ideas?
Rog

[rablack]

Originally posted by Roger Heroux
I have an active Carvin LB75. When I installed the pre-amp I grounded to the shielding. Now when I remove my fingers from the strings I get a hum/buzz sound. Should I have gounded to the jack input? Also I grounded in two spots on the shielding. Any ideas?
Rog

One idea would be to re-post on the electric bass side of the board. You will get better feedback there. P.S. you should ground to the bridge.

[Roger Heroux]

Thanks rablack. I'm not sure which board you are talking about. I may bring it to a tech to check out for me.

[rablack]

Originally posted by Roger Heroux
Thanks rablack. I'm not sure which board you are talking about. I may bring it to a tech to check out for me.

There are two separate discussion boards on this website. One for electric bass [BG] and another for double bass [DB](acoustic, upright, string bass, doghouse, that big thing jazz and symphony guys play, sometimes with a bow). You happened to post your question on the double bass side of the site. Not too many folks over here have to worry about shielding hum or grounding issues. We spend all our time searching for the perfect string or bow and trying to figure out if that bass we want is really worth a second mortgage on our house.

[Christopher]

I don't mean to encourage too much BG content here, but you should solder the preamp ground to the ground terminal of the output jack rather than the shielding. Keeping the signal ground and shield ground separate should help with your noise problem. Of course, if you're using single coils, be prepared to cope with some noise, regardless of how you ground.

[Roger Heroux]

Sorry everyone! My mistake.