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Post by mr_sooty on Mar 12, 2012 18:40:25 GMT -5
I stumbled across this while reading peoples posts on the pros and cons of the whole 'star gounding' idea. I've done the sheilding and star grounding found at GuitarNuts.com before, and while I found it helped a little, I figured it was probably more due to the sheilding than the star grounding. I was searching other peoples experience with this, and stumbled accross this post:
There is a new method of thinking within the idea of "star grounding" that has proven very beneificial to noise issues in guitars.
years ago Some engineer decided that "Ground" should be "everywhere" in a circuit thereby making it easy to wire only the "hot" signal.
but, by looking at the "ground" as another completely seperate signal and trying to "force" it to travel a specific path within the layout of the circuit, you can make any shielding in the circuit become more "active" so to speak. this is not an easy concept to explain without showing it . so I will leave you with an example to ponder.
Imagine a strat with full shielding. connect all the pickup grounds to the back of the vol, pot as per "normal" . now, without altering anything else in the circuit, move the output jacks ground wire from the pot back, to the sheilding on the floor of the cavity, and make sure that the guitar will only work when the guard is fully screwed in it's normal position... your "forceing" the ground signal to flow through the sheilding to even get to the output jack. this mod alone can drop another 6Db in noise if done correctly.
and if you want a Strat to be completely silent. lift all the pickup grounds with a .005 Cap. this will give a notch filtering effect in the low mids. but it will leave your highs alone. and there wil be NO hum at all.
This sounds rather interesting. I'd be perfectly willing to give it a go just for experimentation's sake, but of course I've now got noiseless pickups in my Strat again and I've just sold my old ones. Anybody willing to give this a try and report their findings? I'm dying to know if it works. Or has anybody here already tried it?
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Post by reTrEaD on Mar 12, 2012 19:25:33 GMT -5
This sounds rather interesting. I'd be perfectly willing to give it a go just for experimentation's sake, but of course I've now got noiseless pickups in my Strat again and I've just sold my old ones. Lucky for you, or you would have wasted your time. Anybody willing to give this a try and report their findings? Lucky for "anybody" I'm posting to save them from wasting their time. I'm dying to know if it works. It doesn't Or has anybody here already tried it? I haven't. But I don't need to. It's as baseless as the magical "urthman" shiz I read a few days ago. Lifting your pickup grounds is pointless and actually counter productive. Forcing your "ground signal" to travel though the shielding to get to the output jack will cause MORE noise, not less. Hint: Ground is not a "signal". 6dB! Sounds impressive. One might think this hack actually tested and MEASURED his results. I assure you he did not. For best results, signal commons and shielding should be kept SEPARATE, then joined together at the latest possible point. Unless you're willing to run a 2 wire + shield cable to your amp (I'm not), this means at the output jack if practical, or at the back of one of your pots, if necessary.
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Post by darkavenger on Mar 12, 2012 20:18:12 GMT -5
+1
That sounds like a bad idea.
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Post by mr_sooty on Mar 12, 2012 20:31:53 GMT -5
Good to know. So do you guys reckon that there's much point in 'star grounding' a Strat as per the Guitarnuts instructions? Or is proper sheilding enough in it's own? Does a normal Strat circuit really have ground loops?
I don't know much about electrical theory, I'm just good at following instructions.
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Post by reTrEaD on Mar 12, 2012 21:09:27 GMT -5
I don't know much about electrical theory, I'm just good at following instructions. Not a bad place to be, really. Especially if the instructions are good ones. Good to know. So do you guys reckon that there's much point in 'star grounding' a Strat as per the Guitarnuts instructions? Or is proper sheilding enough in it's own? Does a normal Strat circuit really have ground loops? Yes. Mostly. Yes, but... Ground loops can have a profound effect if the currents are high. But the currents in a guitar are in the microamp range. So the effects caused by ground loops are quite small. Shielding a Strat is HUGE. If the pickups were hum-canceling and all the wiring was done in shielded cable, you would STILL get a small benefit from cavity shielding. But in a Strat, they aren't. So the benefits from cavity shielding are sorely needed and the effort pays off big. Keeping the signal commons separate from the shielding until the two systems are finally joined together is best, but I'm not convinced the difference would be noticeable. In the QTB schemes, it's necessary to keep the two systems separate to allow direct connection of the signal common to the sleeve of the output jack and capacitive coupling of the shielding to that same point. But the "safety" afforded by coupling the shielding via a capacitor is marginal, at best. And the cap WILL reduce the shielding effectiveness. I don't use a "safety" cap on any of my guitars.
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Post by mr_sooty on Mar 12, 2012 22:15:00 GMT -5
It's interesting because on my old 57 reissue Strat I did the whole shebang, sheilding and star grounding, and it definitely seemed to be alot quiter. On my newer American Standard I did the sheilding, but didn't bother with the star grounding because I read somewhere it was fairly pointless. I don't think it was as effective, the American Standard doesn't seem to be as quiet as the 57 was. However the 57 is long gone now so I can't compare properly, could just be my imagination. As I said my Am Std has noiseless pups in it now, so nit much point trying the star grounding at this stage. It didn't actually occur to me to give it a go before I bought the new pups.
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Post by reTrEaD on Mar 12, 2012 22:27:30 GMT -5
I just finished some google searching. Interesting. I found this: www.nzguitars.com/forum/viewtopic.php?f=8&p=498261 (quite a raucous bunch, eh?) But more importantly, I found this: searcystringworks.blogspot.com/2009/04/buzz-kill-star-grounding-myth.htmlIt appears the quote in your OP came not from a blog, but from a wannabe poser who COMMENTED on the blog. Seriously, friend. Consider the source. I read the blog itself. It's not half bad. I think he is missed some of the finer points, but for the most part, he got things close to being right. As far as the comments, you already know my opinion about one of them. Edit: It's interesting because on my old 57 reissue Strat I did the whole shebang, sheilding and star grounding, and it definitely seemed to be alot quiter. On my newer American Standard I did the sheilding, but didn't bother with the star grounding because I read somewhere it was fairly pointless. I don't think it was as effective, the American Standard doesn't seem to be as quiet as the 57 was. However the 57 is long gone now so I can't compare properly, could just be my imagination. As I said my Am Std has noiseless pups in it now, so nit much point trying the star grounding at this stage. It didn't actually occur to me to give it a go before I bought the new pups. Hard to say, really. Unless two things are IDENTICAL to start with, the cause of two different results will remain unclear.
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Post by newey on Mar 12, 2012 22:34:37 GMT -5
Mr Sooty- Good to hear from you again! Welcome back! ReTrEaD has got you on the right track, I don't have much to add to what he's already said. Star grounding was never meant to have anything to do with noise reduction - and it doesn't. It is necessary to do if you are going to use the "blocking capacitor" so as to isolate the user-touchable components (in part, the jack plate remains unprotected). It's also one of those "best practices" things that's a good idea for lots of reasons. As RT notes, John Atchley overstates the issues with ground loops on the original G-Nutz site. ChrisK's post on the blocking capacitor lays out the skinny on the ground loops "issue". I don't use a "blocking capacitor" in my guitars either. If you don't use a tube amp and don't plug your amp into unknown/untested wiring, the odds of anything untoward happening are miniscule. If you play through a tube amp with the old style two-prong power cord, your risk rises appreciably. Your first step, if this is the case, should be to rewire the power cord to modern standards, or have it done by a tech if you don't know what you're doing inside the amp. The blocking cap provides some minimal increment of safety, but the cord is a much bigger issue. As far as "elevating the grounds with a cap" and/or using the shielding as a part of the signal return, the fact that the writer speaks about "grounds" as if this were a DC circuit is a telling point. For example, the statement that: is meaningless. What in the wide, wide world of sports is a "ground signal"? And, by what conceivable mechanism would this reduce noise? Remember that your guitar signal is AC, and that the signal will be flowing in both directions, oscillating many times per second (depending on the rate of string vibrations)- and the unwisdom of putting a cap in there or running the signal through the shielding should be immediately apparent.
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Post by darkavenger on Mar 12, 2012 22:44:15 GMT -5
Well when your touching the strings, aren't you acting as a ground too No but seriously, the biggest change you'll notice by star grounding would probably be from the added wire and metal mass.
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Post by reTrEaD on Mar 12, 2012 23:14:19 GMT -5
Well when your touching the strings, aren't you acting as a ground too Big ole bucket o' noise, much?
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Post by mr_sooty on Mar 13, 2012 0:09:57 GMT -5
Mr Sooty- Good to hear from you again! Welcome back! Thanks. I always come here when I have technical questions as this forum has been extremely helpful for me in the past. I've learned stacks of stuff here. As you've noticed reTrEaD, other forums aren't always so helpful!
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Post by reTrEaD on Mar 13, 2012 9:19:31 GMT -5
As you've noticed reTrEaD, other forums aren't always so helpful! hahaha. It's like they want to tee off on anything but the actual topic, if they aren't able to offer a useful answer.
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