[LAU] Shielded electrical wiring for studio (or not)

[Dale Kazakore Powell]

On 04/06/15 05:21, David Christensen wrote:
> On 06/02/2015 06:32 AM, Glen MacArthur wrote:
>> ... I've received a few mic
>> shocks to the lips over the years when I used to run a vintage amp 
>> without
>> a ground (it only had a ground lift toggle switch)... It didn't take me
>> long to upgrade the wiring to a fully grounded cord.. :)..
>
> I'm curious -- if an electric guitar amplifier has a two-conductor 
> power supply cord (with hot and neutral conductors only) and a "ground 
> lift" switch, what does the switch do?
>
>

I would expect exactly the same thing as ground lift should do on every 
other piece of equipment. Remove the connection to the shield on the 
balanced output. Sure this wont help with eliminating ground loop/hum 
when the kit only has two pin mains but maybe the same amplifier module 
has been used in multiple cabinets etc, some of which are earthed. Or 
maybe it's to prevent a floating ground emanating from another piece of 
equipment downstream from being able to put a voltage onto your guitar 
strings through the signal ground.

Regards, Dale.