Ground Lifts - Dangerous to Use?

[TheTaylorplayer]

I've read about ground lifts... to help reduce single coil hum, amp buzzing, etc. Aren't they dangerous? If I understand the concept, you are basically removing the "grounded conductor" -- third prong on the male plug end by use of an adapter -- and leaving just a hot & neutral. Is that correct?

Or is there circuitry involved here that I'm not aware of (like an electronic version of same)? Please advise -- I've always been curious about that issue.

Thanks in advance.

[drgonzoguitar]

If you are wanting a "cleaner" ground to prevent hum, do not remove the ground. A difference of ground potential between a PA and a guitar could kill you. I saw someone in the USAF get lit up pretty good when I was in tech school (test equpment vs. wideband transmitter). You want something that filters the noise out. I would recommend this

http://www.ebtechaudio.com/humxinfo.pdf

It leaves the ground in place while preventing hum!

[JanD]

When using tha ground lift option you are disconnecting your gear from ground.
This can be done when your gear is connected to a PA system for example.
Your grounding will then go trough the xlr cable from your gear to the PA mixer.
This can reduce/eliminate ground loops....

I prefer to pull another power cable (Incl ground) from the same powersource as where the PA mixer is getting it's power from.
This will also eliminate the ground loop, and you are no longer exposing your delicate electronics to a voltage difference.... so you save "your" equipment..

Hope it's a bit clear...


Regards,


Jan

[Mark Robinson]

It's a hell of a lot safer to attack ground loops at the other end of the signal chain, the input. When you daisy chain amps for instance, get a Lehle or Framptone switcher which includes ground lifting of the input as an option. These are just two that I know have it and I know work great, there are certainly others, Radial etc. I just have not used them.

If you use a cheater, then your are at a big risk if something happens and breaks the neutral path of either of your amps. With tube amps, this sort of failure is a real possibility and there are so many great old amps out there still running that can deliver 120v right to your hands, it aint worth it. Get the old dogs grounded, and be smart about chaining together amps.

It's not that hard to do it right. Isolated voltage sources for the pedalboard are a good idea too. Just as a noise reduction strategy, if your rig is put together intelligently, your hum yeild goes way down. No need to even think about ground lifting.