Hoffman Amplifiers Tube Amplifier Forum
Other Stuff => Guitars => Topic started by: 12bz7 on May 06, 2013, 02:13:25 am
-
I have a strat which needs to be shielded so that i can gig with it.
Would this be a better grounding system for a strat or tele with single coil pickups or am I over thinking it? The basic idea is to keep shielding ground
seperated from pickup ground until they meet at the amp input jack.
1. Shield body with copper tape.
2. Replace standard jack socket with stereo socket.
3. Connect shielding to ground of the socket.
4. Connect pickup circuit ground to 'ring' connection of socket.
5. Connect output wire to 'active' connection of socket.
Use a microphone cable for a guitar cable (twin core and outer shield) wired as stereo jack guitar end to mono jack the amp end.
Has anyone tried this sort of setup?
-
Also rewire the switch so that inactive( unused) pickups are switched completely out of the circuit when not in use to help eliminate external noise.
-
I use the www.guitarnuts.com (http://www.guitarnuts.com) shielding/grounding scheme + series resistors. I don't use a stereo jack. I do: use shielding paint & thicker hook-up wires; eliminate ground loops; and keep signal ground separate from chassis ground. I also place series resistors in line with each PU connection to the SW. Using the Rule of Tens, and assuming 250K pots, you can use up to about 22K resistors. This helps isolate the PU's from ea other; and probably attenuates some noise.
-
I have a strat which needs to be shielded so that i can gig with it.
I use the www.guitarnuts.com (http://www.guitarnuts.com) shielding/grounding scheme ...
I did the GuitarNuts shielding thing when it was first announced back in the late-90's. You can quiet down a Strat, but you can't avoid the fact that the single-coil pickups still catch hum out of the air.
What I mean is you will notice that if you face the pickups towards a noise source, you will hear noise through the amp even with extensive shielding in place. If you move the guitar's position or get further from the noise source, the noise will be reduced.
The problem is, the exact same thing happens with a non-shielded Strat. If you truly have to get rid of allnoise, it will take more than shielding.
-
The radar paint will go a long way. You mentioned that this will (hopefully) be a gig guitar. Have you thought about maybe replacing the pups with some Lace Golds and call it a day? They come pretty darn close to stock and you can eliminate the hummmm. Sometimes it's just not worth the effort - especially when the audience will not be able to tell the dif. Or keep it stock for the studio and buy a dedicated gig guitar.
Good luck!
Jim
ps I've been trying to shield everyone from Tele's for years and Tubenit keeps foiling my plans!!!
-
Thanks for all replies, it's much appreciated.
Yes I will check out the GuitarNuts site and study the options over the next week. The guitar needs shielding anyway so it could be a good experiment trying different methods and see just how quite i can get this beast. I will report back with my findings.
Thanks again
-
Seconding other points made: in a gig situation, normal hiss or hum from your rig will be drowned-out by the rhythm section; and, unless you're playing a concert to a quiet crowd, by the ambient noise in the venue.
-
All you really need is some 3M 77 spray adhesive, and some aluminum foil. Though I'll admit the sticky back copper is easier to use. Myself, the only thing I ever use is shielding paint, but then I'm doing a lot more of them than you'll ever do, so it makes a lot of sens for me.
Gabriel
-
Shielding paint works well. Copper foil does too. I don't worry muc about ground loops inside a guitar. GuitarNuts site is great but a bit overboard IMHO. Don't need a star ground in there let alone separate signal ground running to the amp.
Spray adhesive and heavy duty aluminum foil under pick guard.
-
The problem with copper foil is that if you use adhesive strips, and overlay them, there's no electrical connection from strip to strip. The adhesive acts as insulation. So I've heard - I've only used paint.
I agree that ground loop evasion may seem overboard - until you have hum. This can vary from venue to venue. IMHO: better safe than sorry. I must confess I hate ground loops on principal and take pride in separating chassis ground from signal ground. No lugs soldered to pot bodies for me.
-
The problem with copper foil is that if you use adhesive strips, and overlay them, there's no electrical connection from strip to strip. The adhesive acts as insulation. So I've heard - I've only used paint.
Depends on the copper foil. The ones that are designed for shielding (as opposed to decorative uses) have adhesives which are conductive enough for the purpose. Plus, even without that, the adhesive just acts as a dielectric, making the pieces into a low value capacitor that will be completely open to the AC signals you are trying to block.
There is a lot of nonsense on the internet about shielding guitars, and it is just that - nonsense. It really is a very simple thing, and the conditions inside a guitar are really very forgiving. You don't have very minimal amounts of current, and the impedance of everything is relatively low compared to the input of the amplifier. It's a bit different for acoustic pickups/preamps, because the impedance of the pickup is so high, but on an electric guitar any method of shielding it will be just fine. As long as you actually DO shield it, of course. Copper foil, aluminum foil, shielding paint; it just doesn't matter. In the real world, you will never notice a difference. I find shielding paint to be easiest, but as I said earlier that is in large part because we shield a lot of guitars at the shop, and so it make financial sense for us to buy a can of shielding paint. You need to do at least two coats of the stuff, by the way. But we've done them with aluminum foil and spray adhesive, we've done them with sticky back adhesive too. They all do the job just fine.
Gabriel
-
The problem with copper foil is that if you use adhesive strips, and overlay them, there's no electrical connection from strip to strip. The adhesive acts as insulation. So I've heard - I've only used paint.
I agree that ground loop evasion may seem overboard - until you have hum. This can vary from venue to venue. IMHO: better safe than sorry. I must confess I hate ground loops on principal and take pride in separating chassis ground from signal ground. No lugs soldered to pot bodies for me.
Being compulsive, I put a dab of solder connecting each piece of copper foil.
I also make sure there's solid contact in several places between the cavity liner and the shielding under the pick guard.
Cheers,
Chip