Submitted 15 hours ago by a_non_monotonic_function@lemmy.world to askelectronics@discuss.tchncs.de
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Got a new (to me) older audio stack. Not used to some of the earlier electronics conventions.
The system has two pronged cords, and has external grounding. How much danger am I looking at here? I’m not 100% certain how to use it properly.
Zero danger as long as you don’t connect something other than a ground or shield to these.
I’d see if you can find a circuit diagram for the equipment, then compare it against what you actually have.
It might be that there was a genuine issue with the equipment that was fixed, or it might be that the fix was actually something else entirely.
There’s no way for us to know what you’re dealing with.
I have the manuals and I can check those. I can also easily get the model numbers off the units. Are diagrams something that you can find for old hardware online?
And I appreciate the assistance. My background is in computer science, so my electrical engineering abilities are slim.
Fellow computer geek here … also a radio amateur.
No idea what the availability of circuit diagrams is for your gear. In amateur radio equipment the user manual regularly has them, sometimes as big foldout sheets. I’d be surprised if they didn’t exist.
The dangers are limited unless you hit an edge case which you’ll want to avoid. In other words, you’d have to be really unlucky. Surges can happen with audio equipment easily though.
The principle of grounding is actually simple enough: when something goes wrong with the current, for instance if it can’t move through the wires it should move through, it’ll try to escape. Grounding makes sure that it moves through a dedicated wire to somewhere it can no longer do harm. Cars, for instance, use their frame as a ground, which will conduct the current into the tires and into the ground (ie Earth) if necessary.
This is probably 25% accurate so I’ll invite any electrician to correct me but I am fairly confident this will do as a basic answer.
You hook up the GND contacts to anything that is not connected to anything electrical, preferably something non-conductive at the end of it, you’ll be fine.
Thank you for the first response. I look forward to possible second opinions as you suggest.
And this makes a bit of sense to me. If the medium doesn’t matter I could probably just stick a bolt in the wood next to the units. That’ll keep any wires fairly short.
Basically I was showing the system on the audio forum and asking some questions regarding the unusual number of AC plugs. One of them asked about the age and grounding, and suggested there might be a serious danger.
I have only a very basic knowledge of electricity and an even smaller knowledge of amps but I have heard about certain amps that would be susceptible to immense power surges which would short out some circuits and that power needs to go somewhere. If it’s not grounded properly it might release its current into the air where it’ll find you, or maybe catch fire.
The specifics of this and why or how this happens should be findable online.
Most likely it’ll also have something to do with the higher voltage direct current being transformed into a lower voltage alternating current. But why and how you’d need to be properly grounded for that is beyond me.
socsa@piefed.social 10 hours ago
The ground straps are for a turntable, not a power ground. The audio signal from a record player is incredibly tiny, which means it needs more amplification stages (usually if you have a phono input, it has another pre amp stage). Because of this it is important that the turntable and pre-amp have a common ground reference to eliminate things like a DC offset or ground loop which would otherwise be amplified more than other audio artifacts from other sources.
a_non_monotonic_function@lemmy.world 10 hours ago
Sounds like you’re confirming what I’ve been hearing from other people, that neither of these grounds contains any real danger?
And as for grounding the turntable, that makes a bit of sense, however I have a fairly modern one and I’ll have to check it. I don’t know that it actually has an external ground beyond the three prong plug.
Is grounding of the turntable still relevant in that case?
socsa@piefed.social 10 hours ago
I think most modern turntables have a built in pre-amp so it’s less of an issue. If it doesn’t have a ground lug itself then it’s probably not an issue.