relics
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Post by relics on Dec 12, 2007 20:58:45 GMT -5
What would happen if the ground wires for the guitar were not connected at all?
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Post by ashcatlt on Dec 13, 2007 0:00:56 GMT -5
Welcome...
...and wow
The semantic answer: If wire is not connected to ground, it's not a ground wire.
But that just leads us in circles.
There are several points where the guitar circuit hits ground. Removing any one of these will have different effects on the signal.
First the biggy - If a pickup is not connected on one end to the ground side of the amplifier input then we've got an open circuit in the guitar, and it is just a big antenna with strings. Theoretically you would likely hear a lot of static, perhaps some radio broadcasts, but no actual transduction of the string signal. I wouldn't be surprised if, in practice, you did hear some of the strings. It certainly won't be anything much useful unless you're into the extreme experimental thing. If you are, PM me...
Then you know, there's the ground connections on the pots.
The "ground wire" on the volume pot is generally one tab bent back and soldered to the case, with a wire from there to ground. If there is no connection to ground from that lug, the pot acts as a reostat - rather than a voltage divider - and has a much diminshed effect on the overall output volume. Among other things, you'd never get the volume to go all the way off.
The tone pot is usually connected to ground through a capacitor. If that cap doesn't connect to ground, the entire tone control becomes vestigal. It won't do a farging thing.
The connections from the body/housing/casing of the various controls (and you can include the pickups in this as well) don't really have to connect to ground in order for the circuit to function. This is more of a shielding convention. Omitting these ground points could cause some noise.
Then there's the "string ground," usually a wire from the bridge. It is not either particularly useful to the circuit. As I understand it from somebody around here, this connection is meant to ground out the closest, and one of the largest noise sources: you. In my experience, for some guitars this wire is kind of optional.
Did I miss anything important?
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Post by sumgai on Dec 13, 2007 14:36:08 GMT -5
ash, Nope! Earns a +1 from me! ;D relics, Hi, and welcome to the Nutzhouse! Where are you going with this question? Do you have a specific goal in mind, or were you just wondering for the sake of learning something? sumgai
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relics
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Post by relics on Dec 13, 2007 17:27:44 GMT -5
just wondering of my ground wires through the capacitor were connected....
it'd be a shame if I died. Really.
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Post by ChrisK on Dec 13, 2007 18:47:53 GMT -5
Do you mean "if the tone cap is grounded"? I agree, however, is this related to the question at hand?
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Post by sumgai on Dec 14, 2007 0:30:44 GMT -5
relics, For spiritualistic discussions, the proper forum is at the end of the hallway, turn right, second door on the right. Tell 'em Jimi sent ya. Otherwise, unlike Chris, I'm assuming that you're speaking to the isolation/shock prevention capacitor in the QtB article found on the Original GuitarNuts website, is that correct? sumgai
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Post by ashcatlt on Dec 14, 2007 14:11:35 GMT -5
Sory to break it to you, but you will die. Considering the issues this world is having with over-population at the moment, I'd have to say it'd be a shame if you didn't. Course it would be great if you could hang out and make some music for a while beforehand. That capacitor which I think you're talking about is meant to go between as many as possible of the metal parts of the guitar (most noteably the strings/bridge) and the ground side of the amplifier's input. It's meant to save you in the case of an extremely rare and very dangerous situation involving old tube amps in poor repair. It's far more likely, given historical statistics, that you will die from mixing barbituates with alcohol and drowning in your own vomit. ('Course, my friend says he was on the phone with Jimi when he was murdered, but that's another story...) A much more likely cause of electrical stress to your body will be what I've always heard called "leakage" which happens when your amp has a different AC ground potential than something else that you touch at the same time. This could be a concrete basement floor (even through carpet and socks!), your bass player's amp, the FOH PA that your mic is connected to. This is more often just annoying, but it can bite you pretty bad from time to time, and CAN BE LIFE THREATENING in some cases. The cool part about that is that isolation cap won't really help at all for this problem. You may recall that I mentioned that none of these metal parts (pot shafts, pickup covers, switch bodies, even string ground) really have anything to do with the functioning of the circuit. If you want to be absolutely sure you won't get this leakage shock, just don't connect any of those wires. May cause some noise, but... Truthfully, the best bet to avoid either of these problems is to make sure that your amplifiers are in good repair and properly grounded. Then, read this. Get yourself the proper test equipment (really pretty inexpensive) and follow the instructions in that article to test the wiring in every venue where you intend to plug in. And by venue I mean not only the club (or stadium, as the case may be) but also your bedroom, your friend's basement, your uncle's barn, or whatever.
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Post by sumgai on Dec 14, 2007 14:27:55 GMT -5
Or you could just use an RF "cable"........ sumgai
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dressner
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Post by dressner on Dec 17, 2007 3:23:45 GMT -5
I believe I'm going to like this forum.
ashcatlt gave me repeated laughs out loud in this thread, and along with sumgai and others is full of great useful information
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Post by wolf on Dec 17, 2007 15:33:16 GMT -5
I have never eliminated the string grounding on any of my guitars and I consider it essential. Sure you could eliminate it by cutting the wire that connects the strings to the guitar circuit which eventually goes to your amp but then you will get more hum and interference. Yes, it's a little more dangerous but hey, the improvement in sound is worth the risk. A long time ago (way back in the 1960's) I played at a pool party. That was back in the days of 2 prong plugs and no home wiring safety features such as GFCI's. Anyway, I didn't get knocked into the pool but all the water on the ground made things very painful when touching another amp, guitar, microphone, etc. Heck, it hurt just touching the power switch. There have been many fatalities attributed to electric guitars so always be careful with your setup. Then again, I never disconnect the string grounding.
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relics
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Post by relics on Dec 29, 2007 22:58:11 GMT -5
What about the tremolo ground wire. Does it need to be connected?
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Post by sumgai on Dec 30, 2007 2:42:14 GMT -5
relics, By definition, they're one and the same. It'd be kinda pointless to have a TremoLeo device that didn't operate on the strings, no? Contact between the two is pretty much unavoidable, or so I strongly believe. So to answer your question..... Yes, according to our doctrine, the TremoLeo portion of the guitar needs to be grounded, and it will be so, if the strings are grounded. (In all Strat-type guitars I've ever seen, the string ground contact was made via a wire being soldered directly to the TremoLeo device.) HTH And BTW, a belated welcome to the NutzHouse! ;D sumgai
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relics
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Post by relics on Dec 31, 2007 20:01:04 GMT -5
If the tremolo ground isn't there, will the amp still receive a signal from the strings?
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Post by sumgai on Dec 31, 2007 21:48:07 GMT -5
relics Yes, but much buzzing and humming will ensue, whenever you pickup and strap on your guitar. Touching the strings won't make it go away like it would normally, and that's a bad thing. HTH sumgai
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