Loud hum problem with steel and computer

RB Jones · Post by **RB Jones** » 7 Mar 2003 9:01 pm

I'm trying to record onto my computer with my steel and regular electric guitars. But the 60 hz hum is tremendous when I get even within 10 feet of the computer. Both steel and guitar have single coils pickups, but they don't make near that loud a hum until I get near the computer.

Is it possible that the wiring in my house, which is about 80 years old, isn't polarized and causing the hum? I know computers and monitors put out a lot of RF hum, but this appears to be excessive. Has anybody found a filter or something that can cut down on this?

Until I can figure this out, I'm not going to be able to run the output of the guitars straight into the computer from my processor like I want to. (I don't have the luxury of having a studio where I can mic a live amp.)

Any help is appreciated.

RB

Paul Osbty · Post by **Paul Osbty** » 7 Mar 2003 10:30 pm

I take it you run from the guitars into a processor and then to the computer.

I had a similar problem once. I connected a chassis screw of, in your case, the processor to a chassis screw of the computer and it went away.

Is your house wiring 2 or 3 prongs? If 2, replace the outlet sockets with 3 prong sockets. The 3rd prog just connects to the steel mounting bracket of the socket assembly. See which wires go to which prongs. Usually they are color coded. Make sure they all match.

RB Jones · Post by **RB Jones** » 7 Mar 2003 11:36 pm

Thanks Paul,
I'll check these out. The ground wire makes sense.

RB

Jerry Gleason · Post by **Jerry Gleason** » 7 Mar 2003 11:50 pm

If the problem is RF from your computer monitor, grounding won't make much of a difference. You can easily determine if that's the problem by simply switching the monitor off (leaving the computer on) and see if it goes away. If that's the source of the problem, try turning your guitar 90 degrees from it each direction and see if it diminishes or goes away entirely. I had a similar problem before I changed from a CRT to an LCD flat panel monitor.

Earnest Bovine · Post by **Earnest Bovine** » 8 Mar 2003 9:19 am

Try the easy stuff first, like turning off the computer monitor. Try turning your guitar of course.
If you must leave the monitor on while you play, point it direclty at your pickup. There is much more radiation (noise) from the coming from the side of the monitor than from the front.

Tyler Macy · Post by **Tyler Macy** » 9 Mar 2003 12:06 am

I'd almost guarantee you it's the monitor. Just turn the monitor off and see if the hum stops.

I play single coil guitars and do home recording into a PC. My multitrack software has keyboard shortcuts for transport functions (i.e. "R" for record). Before laying down a track, I turn off the monitor, then hit R, then play away.

RB Jones · Post by **RB Jones** » 9 Mar 2003 6:30 pm

Thanks for all the help. Well I turned off the monitor and it didn't help so I must have interference coming from the computer itself or possibly the wiring in my house. It's much worse in the room where I have my computer. I can turn the guitar and reduce it somewhat but it doesn't eliminate it.

I'm also going to check the polarity of my outlets. The old amps had switches on them to flip the polarity to cut down on hum. This new equipment doesn't have that. I presume they figure that all houses are grounded and polarized properly. My house was built in the teens or 20s.

RB

Jim Palenscar · Post by **Jim Palenscar** » 9 Mar 2003 7:31 pm

I had a very similar problem when the computer and my recording stuff (including the steel, etc) were hooked together and the only way I could solve it was with Radio Shack's Audio System Ground Loop Isolator (Cat.#270-054A)~ mo betta now[This message was edited by Jim Palenscar on 09 March 2003 at 07:31 PM.]

RB Jones · Post by **RB Jones** » 9 Mar 2003 9:05 pm

Thanks Jim. I'll check into it.

RB

David L. Donald · Post by **David L. Donald** » 10 Mar 2003 4:12 pm

The ground loop isolator seems the best choice. if the house was the issue it would do it in any room and though your amp too.

All system components should be on the same grounding source. or lifted from it.

Also it could be the cable or adapter you use to get into the computer.
You could try a small USB audiop interface farther from the monitor and computer itself.

have in a pinch grounded to the recording end a large piece of foil between the instrument and the hum inducing source.... but that's only a little help with particularly old badly grounded instruments. Very Micky Mouse.[This message was edited by David L. Donald on 10 March 2003 at 04:15 PM.]

DroopyPawn · Post by **DroopyPawn** » 10 Mar 2003 9:54 pm

If you can't get rid of the hum, you can always use a parametric eq to remove the irritating frequency from the mix.
gs

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David L. Donald · Post by **David L. Donald** » 11 Mar 2003 1:45 am

Droopy, that's a solution, but much better to get to the root of the hum problem. Otherwise it really messes with your sound. And if you need to buy a parametric EQ that money should solve the problem not mask it and change your recorded sound.