I'm also wondering if an addition of a
diode to the wiring of the device might not eliminate so possible issues with
feedback, < electronic not audio> back into the outputs of the sound card.
I agree that using some external, possibly USB, device might not also help, Getting a clean signal in the first place is an issue.
Quote "
Eboy87I highly reccomend that you do NOT lift the AC ground, people are killed that way.
I've never heard of anyone being killed by lifting the
ground on Audio equipment, but I guess it could happen.
Van although you haven't heard of it doesn't mean it hasn't happened. Unless you can get hold of a detailed coroners report that states the earth was lifted it would normaly be put down to faulty wiring.
Musicans have been killed on
stage when their microphones have gone live. This may have been because the earth
wire came loose or was deliberately disconnected. Most of the time the
shield on connectors land up being connected to the metal chassis. The electrical earth is also connected to the chassis. If you
disconnect the electrical earth and the live
wire comes into contact with the chassis it is now live. Because you have disconnected the electrical earth the fault won't be detected by the blowing of a
fuse or
circuit breaker. So now someone touchs the chassis and or the
shield on a connected lead and they can become the path to earth and death.
So as you can see lifting the AC earth (
ground) can be deadly and should not be done.
The safest way to isolate sound equipment from a mains earth hum is to use a
safety isolating
transformer. This is if using DI boxes haven't being able to remove it at the signal
ground level. Theorecticaly you could still get a
shock but your equipment would have to have two electrical faults on the mains wiring at the same time. In which case it is quite unlikely that the equipment will actually work.
Please don't confuse
ground lift at the signal
level with lifting the electrical AC earth.
Ground lift generaly refers to disconnecting the signal
ground between two pieces of equipment. When using balanced systems the
ground is not required to provide a signal path for the audio. In fact when it is connected it may become path for hum. That is why a lot of DI boxes have
ground lift switches.
Just a cautionary note to us older members, including myself. I believe when it comes to
safety we should always err on the side of caution in any post we make on this board. With experience we may be able to judge the
level of risk involved. But this doesn't mean we should. What is the old fighter pilot saying " there are old pilots and bold pilots but no old bold pilots". However less experienced members may not and take it that if he says it works then ok.
I can remeber hearing years ago about airplane crashes that it normally is not one thing but a chain that leads to disaster.
For a recent example the Rhode Island tragedy. For example if the proper flame proof
insulation had been used then maybe the pyrotechnics might not have started such a big fire so quickly. What if lower
level pyro's had been used.
There is a discussion about fire
safety " fire marsall" going on at the moment. In it people have mentioned wedging doors open to move stuff or because they haven't proper cable runs installed. This maybe fine 99% of the time but it just needs something to go wrong that this compounds the problem. The same with empty fire extinguishers, hose reels blocked. It all adds up.
Sorry for the rant but there have been a few
safety issues raised on this board in the last few days.