Every once in a while I get an email from someone asking me about the wonders of the Star Grounding wiring system featured on the GuitarNuts website. Now I like the Guitar Nuts site and there are loads of great information there but this one article is starting to drive me GuitarNuts. The original claim was that by adding shielding and removing ground loops from a guitar or bass equipped with single coil pickups you can drastically reduce hum and noise. But like any good myth the claim has been embellished by time and repetition. Now I'm getting emails from folks claiming that Star Grounding can totally remove all noise from single coil guitars and even help guitars with humbucking pickups. On the other side of the fence there are those who now claim that Shielding and Star Grounding your guitar is a "tone suck" that will harm your carefully crafted tone.
So, is this Shielding and Star Grounding practice worth while or is it just a lot of B.S. ?
Well, just like any good myth it has elements of truth and exaggeration. Let's start with shielding the guitar. Shielding is a conductive enclosure around one or more signal conductors ( pickups, pots, switches ect...), used to keep out electrostatic fields that can cause hum, buzz, or other noise. Shielding is often a good idea on many single coil guitars. Particularly Strat copies that often didn't come with much shielding to start with. A good practice for shielding a Strat type guitar is to use either copper foil tape or conductive paint to shield the pickup cavities and the control cavity including the back of the pick guard. Then this "Shield" is connected to the guitars ground. It's pretty simple and very effective at getting rid of noise. But it will never make your single coil pickups hum free. When folks tell me they have fallowed the Shielding and Star Grounding instructions on the web and noticed dramatic improvements, well, this is why. Shielding helps!
On the other hand trying to reduce noise by hunting down and removing "Ground Loops" inside the guitar via the Star Grounding method is a waste of time. Why? Well let's start by looking at what a ground loop really is. Ground loops are real and they can be noisy little buggers that occur when you can trace a loop in the ground connections between separate pieces of AC powered equipment in your signal chain. Hank Wallace wrote a great article about this over at Atlantic Quality Design. So why can't a guitar have a ground loop? To put it simply it's because a guitar only has one ground path. That being the cord. Because every component in a guitar or bass is grounded at the output jack it was already "Star Grounded" when you bought it. No matter how you wire the guitar all the grounds must converge at the output jack. So basically there is no way to wire it that isn't "Star Grounded". In fact the only way you can get a ground loop inside a guitar is to wire it up with two separate outputs that run to two separate amps and star grounding the wiring inside the guitar won't fix that either.
Some like to argue that the neck pickup lead might be longer then the bridge pickup lead causing a voltage drop that could create a ground loops. But there simply isn't enough wire or voltage inside a guitar to make this a reality. Want to test that assertion? Find a stock Fender Jazz Bass that has RWRP single coil pickups and is noise free with the volume on both pickups all the way up. Now open it up and measure the pickup leads. See? The neck pickup leads are much longer.
So, will shielding your single coil guitar or bass help reduce noise? Possibly. Will it kill the tone of your instrument? Not unless you wrapped your pickup coils in cooper foil. That can cause you to lose some of the high end.
Will Star Grounding your single coil guitar help reduce noise? Absolutely not! No way. It's a total waste of time and should be avoided. Am I being unclear? The problem is that most of the folks who attempt the Star Grounding system on a guitar or bass are electrical novices that might not be too skilled at avoiding cold solder joints or over heating pots or capacitors.So why trip them up by giving them a pointless project to fallow that just adds to the confusion?
Well, I guess that's it for now. Next time we'll tackle the "Aged Magnets" myth.