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My guitar p/ups have suddenly developed a hum now that i'm employing a DAW to record. Even in humbucking mode there's a noticeable buzz. Not sure which component is the culprit but surely it couldn't be my ANUS! Using a CRT monitor though.

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anonymous Thu, 07/11/2002 - 02:06

The main source is usually the CRT. Try to switch it off and see if it is the culprit. Furthermore, try to move your axe around and find the angle at which the hum is at minimum. Try to keep as far from the PC as is practically possible. Make sure your new setup has not developed any ground loops. A good place to read about shielding:
http://www.guitarnuts.com/wiring/index.html

Hope it helps

ah

Opus2000 Thu, 07/11/2002 - 06:41

Audiohead is absolutely correct...this is a known issue with computers and guitars...with the right combination of pickups and location you can sometimes even pick up radio stations through guitars!
Placement of your body and guitar should definately be as far away from the computer as possible!
Opus

SonOfSmawg Thu, 07/11/2002 - 09:45

If this hum is "new", odds are that it isn't the guitar's fault. It's your crt video monitor throwing fits.
The problem is with the magnetic properties of the cathode ray tube, itself. Most likely, de-gaussing will correct your problem. Try this first, and if it doesn't correct the problem, then have one of your friends bring his crt monitor over and see if it does the same thing. If it does, then you may indeed have a prob with your axe, and I can definately help you with that if need be.

anonymous Thu, 07/11/2002 - 09:52

You can get good results by shielding your guitar. They make this really think coper tape taht you line the guts of your guitar with. You also put this on the back of your pick guard. then you run a wire from the bridge to the a screw that srews in to the body and contacts the tape.

My humbuckers are coil taped and I can run single coil will no hum. ;P

d./

michael c Thu, 07/11/2002 - 19:05

Thanks boys! (if you are all boys...i dunno!)
Anyways, i can say straight off that i can't position myself away from the DAW when tracking. I track alone. I'll look at shielding and the quality of the power supply. However! Unlike tape based recording, i can delete noisy guitar passages with the sweep of a mouse. Such easy editing of tracks is still a novelty to me so these options aren't second nature just yet.

Are any of you going to the Nashville NAMM?

SonOfSmawg Fri, 07/12/2002 - 11:30

Trust me on this...
First ... Degauss your monitor.
Second ... If that doesn't work, try another monitor on YOUR system, in exactly the same place that your monitor is.
Third ... If the other monitor doesn't clear-up the hum prob, then the prob is probably with your guitar.
Fourth ... Just putting-in or upgrading the shielding tape in your axe probably will not clear up this prob. There are many other things that should be done to a guitar with interference probs. If you try the other steps first, and the problem still persists, let me know and I will tell you exactly what needs to be done.

anonymous Thu, 08/01/2002 - 07:26

A couple of other points to make:
If you are plugging directly into a board (as opposed to micing a speaker) then a ground lift on a direct box is the way to go. Even active electronics in acoustics, electrics and basses will have a tendency to have a ground hum when plugged directly into a line input (not even including the mismatched impedance and noise induced by having to crank up the gain).
Also, I just installed and wired a set of noiseless pickups for a friend. Every guitarist has probably encountered the scenario where the guitar is wonderful as long as your body is making contact with the strings or bridge, but when you let off you get a ground noise. This is indicative of a poorly shielded guitar or a detached ground wire from the bridge. The copper foil works great on the pickgaurd but for the cavities it is much easier to use a shielding paint. I believe you can get that through stew-mac.
hope this helps and sorry if it is redundant info.

SonOfSmawg Thu, 08/01/2002 - 09:37

Way back in RO's infancy, I had written a post which described my complete shielding mod. However, somewhere along the way, the first several month's posts from the guitar forum mysteriously disappeared. Since several people have asked to have it back, I'll outline it here for you guys. If anyone wants more complete details or has any questions, just ask. Eventually I will make a complete version of my "Ultimate Guitar Shielding Mod" for the RO Ezine.
Personally, I don't recommend shielding paint. It has been known to chip off when it gets old, then you have electrically conductive pieces inside your guitar! Shielding tape is easy to install, and you don't run the risk of dripping it on your guitar finish. Line ALL cavities of the guitar, and cover the back of the pickgaurd and ALL covers.
The bridge ground wire is a must. Use copper as opposed to aluminum that comes standard on most guitars. I use a piece of oxygen-free speaker cable (split down the middle) for this.
Replace the single wires inside your guitar with shielded cable ... including the pickup leads, the connections between all of your pots and switches, and the lead going to your 1/4" jack. Cutting-up a guitar cable to do this is generally a bad idea, as it is too large in diameter, so go down to Radio Shack and they'll hook you up with shielded cable that is smaller in diameter.
If you have active electronics, and the battery(s) just sits in the cavity, make an enclosed case for it out of 1/4' foam, using electrical tape to hold it together. Leave a flap on top for easy battery replacement. This has nothing to do with shielding, but it keeps the battery from rattling-around, and keeps it from touching electrical components inside your guitar and grounding them out.
Like Leo Fender, I'm a proponent of dipping pickups in beeswax. I even dip humbuckers. It's a rather long procedure, envolving a lot of dipping and scraping. In a nutshell ... you'll need beeswax, a small Pyrex bowl (about 5-6" diameter & 2" deep is perfect) , a microwave, a small knife that you don't mind getting magnetized, and a lot of patience. I don't recommend dipping uncovered pickups, as the yellowish wax is very unattractive. If you have uncovered pickups that you want to dip, you might be able to buy covers for them. If you dip humbuckers, you must remove the covers and put the screws back in the pickup, so that the screw holes don't fill with wax ... but you'll have to clean them up later.
Put the beeswax in the Pyrex bowl, so that the bowl will be about 2/3 full when the wax is melted, then put the bowl in the microwave. I don't recommend heating beeswax on a stove as it burns easily. Set the microwave on High for a few minutes, BUT STAND THERE AND DON'T TAKE YOUR EYES OFF OF IT. The second it is completely melted, take it out. DO NOT OVERCOOK IT!
Now to dip the pickups:
Holding the pickup by the lead, dip the entire pickup in the wax, slowly, and take it back out. Allow it to skin over for a few minutes. You will then have to dip the pickup several more times to get a good build-up, but when you dunk them, do it very quickly, or the heat of the wax will remove what you've already accumulated. Allow it to skin over a little bit between dunks. Basically, this is just like old-fashioned candle-making.
Once you have an adequate amount of wax on the whole pickup, you have to carve off the wax that we don't want on there. Remove all of the wax from the top of the coil(s), paying close attention to the poll pieces, as they will have to fit back into the holes on the pickup cover. If you dipped a humbucker, remove the screws and get all of the wax off of them, being careful not to scratch them. Hot water works good to help clean the screws completely. So, at this point, the top of the pickup is ready.
Now you must carefully shave just enough wax off of the sides so that the pickup cover will fit back on. Do this little by little, checking the fit, so that you remove as little as possible.
VOILA ... put the covers back on and reinstall the pickups.
When you're doing this entire mod, it's a great time to replace any noisy or questionable pots or switches. Also, check all of the components to ensure that they are attatched securely, tightening any screws or nuts as necessary. Remember, never over-tighten screws that go into wood, they are easily stripped. Also, when using screwdrivers, pliers, and wrenches on your guitar, do it slowly and carefully, or you could slip and put a scratch or ding in your finish.
The general rule to working on guitars is to do so slowly and carefully. Never try to rush through it, and never guess. If you're unsure about something, STOP, and find the answer to your problem.
And as always, if you need any help or clarification, feel free to ask me.