Amp Hum

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Pughbert

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Ive found myself having this problem whilst recording my latest EP, which im aiming to be of very high record quality. I find that on some e.guitar overdubs, when i play part that dies out e.g - stum and chord and leave it to ring out. - as the guitar sound drops, the amps hum slowly becomes noticable in the backgroung. Gating isnt really an option as far i can see because the hum is mixed with the guitar sound before the guitar fully dies away.

So how do i get round this?

Cheers
 
Answer #1 is try to eliminate - or at least minimize - the hum itself. Find out where it's coming from; is it the amp istelf or is it from your pickup?

Try plugging the amp into a different electrical circuit, and make sure your electrical has a good ground. Make sure all neon signs, floruscent lights and anything with an AC motor is turned off.

Try playing your git in different positions and facing different directions in your room to minimize any pickup hum. Make sure your git cable is high quality and in good shape and is not running parallel and close to any electrical lines, etc.

If none of that works and you just have an amp that humms because it doesn't know the tune, borrow another amp. If that's not possible, then record with your amp at a lower volume where the hum is not as noticable.

If all that fails you, you can always use a noise filter in your software that targets 60Hz (or 50Hz if you're right of the Atlantic). This would take learning to use Audition.

HTH,

G.
 
SouthSIDE Glen said:
Try playing your git in different positions and facing different directions in your room to minimize any pickup hum
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Stay as far from your computer's monitor(s) as possible, and turn away from them. CRT monitors are especially prone to cause major problems in magnetic pick-ups.

Check to see if your amp has a ground lift button which may help. Obviously shielded cables (and balanced, if you have balanced connections available) are in order.

You can always pick-up a power conditioner too (Which isn't a bad idea either way, trust me...).

Check to see that both amp and guitar are also in proper condition (i.e. no loose wires, and proper shielding, etc.).

Finally, don't allow any of your cables to loop around themselves, as doing so allows the cable to recieve and amplify certain RF's
 
I cant see that any of the possibilitys is going to be the problem. Ive tried all these thing before with no luck. The hum is the simple sound that the amp make once its turned on. Its a Line 6 Spider 212, Guitar is a USA Tele Deulux, im using a nice, new fender cable, amps in a seperate room to me, and im not near my monitor.

Its worth saying - this isnt like the hum of a truck, is very quiet and only really noticable through headphones, but not somthing i want to keep.

The turning down option isnt an option - as the hum isnt to do with volume - i turn up, it doesnt, i turn down it doesnt. Therefore I turn up and have no problems most of the time. BUT the problem comes when somthing is left to ring out, then, as the guitar sound drops, this hum become audible.

I really see no way round - but anyone??!

Cheers
 
You missed two suggestions:

Rotate the guitar so that the pickups are at a different angle to the transformer in the amp. If the amp is humming, try rotating the amp.

If you disconnect the guitar cord from the amp and the amp still hums, the problem is a badly regulated power supply in the amp, or a filter capacitor not doing it's job.
 
Can't you fade out the tracks and if push comes to shove, use a sampling of the hum and use something to eliminate the noise, like on Adobe Audition.
 
It seems that if the hum is constant regardless of amp volume setting, you should just record at a high volume, so that your guitar signal is much louder than the hum. If you have a really long guitar note fading out, you may need to also manually fade that track slightly over the top of the nautral fade, so that, at the point the hum becomes noticable, the track volume will be very low. I know this is all obvious, but I think it's about all you can do. Or switch amps.
 
Cheers for the help guys. - The hum is only there when the cord is connected, silence once its removed.

As for turning the amp or guitar around, its doesnt help me. Ive tried all these things before i asked here, but had no luck.

Im sure its just the way of the amp - but that leaves me the problem!

Fading the recording out is how ive been getting around this, but its not ideal as its doesnt compleatly solve it without the fade sounding unnatural, but it seems its how im going to have to carry on getting around it!
 
Pughbert said:
Cheers for the help guys. - The hum is only there when the cord is connected, silence once its removed.
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Troubleshooting 101: if the amp is humming only when you plug something else into it, chances are it's the "something else" that's at fault.

Are your humbuckers actually bucking the hum? ;)

I know you said you had confidence in your cabling, but I'll give you a buck-fifty to one that it's your guitar cable.

(Or on a stomp box/patch cabe that you have between your guitar and your amp.)

Here's a test. Plug someone else's guitar and cable into the sam amp. I fthe hum does not reappear, then you probably know it's not in your amp, but rather in your guitar or cable. Try your cable with his guitar. Does the hum come back now? If so, it's the cable. If not, it could be your guitar picking up the RF.

G.
 
Im with you - i would say it was the cable if i read this post - or the fact that its single coils being used - But its not this!

Ive got a few other guitars - and lots of other cables - all the same.

I study music at collage so take my amp in quite a bit and therfore use it with other peoples cables and guitars too - still the hum rings out.

Again its worth saying - this hum isnt deafening - its just there when the guitar sound drops - or if there no guitar sound playing. So when playing in general the guitar compleatly drowns it out - no probs, but as the guitar sound drops - theres the hum.
 
couple tips...

get a really really clean bass sound a bit hotter than the guitar and fade the guitars just slightly quicker than the bass.

try a foil shielded cable. they're more fragile, but quiter.

seriously, WORK THE ROOM. try every freakin' angle imaginable.
 
Turn the gain down a bit. I have found, with both modelers and real amps that there is a point as you turn up the gain knob, the hum becomes really noticeable. There is usually a very clear and noticeable threshold. If you back your gain off to JUST below that point, it is usually still enough gain, but without 90% of the noise. You really have to search but you can usually find this threshold, it may be something you never noticed playing but becomes very evident when your record.
 
grn said:
use a sampling of the hum and use something to eliminate the noise, like on Adobe Audition.
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While I agree with what everyone's saying about trying to identify the source of the problem and attack it there, it sounds like you've done quite a lot of investigation with no results. Especially if it's a really slight hum like you're saying, maybe there's just no way to eliminate it completely. I think grn's recommendation is a good one though. You could sample the hum by itself and use that sound to create a filter to apply to the track to strip out the hum. I know that Cool Edit, which I believe is now Audition, had that - I used it when transferring old tapes to the digital realm to remove the tape hiss, and it worked really well.

Good luck! :)
-Jeff
 
guttadaj said:
While I agree with what everyone's saying about trying to identify the source of the problem and attack it there, it sounds like you've done quite a lot of investigation with no results. Especially if it's a really slight hum like you're saying, maybe there's just no way to eliminate it completely. I think grn's recommendation is a good one though. You could sample the hum by itself and use that sound to create a filter to apply to the track to strip out the hum. I know that Cool Edit, which I believe is now Audition, had that - I used it when transferring old tapes to the digital realm to remove the tape hiss, and it worked really well.

Good luck! :)
-Jeff
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You can do that? That is sweet....
How 'bout in cubase?
 
amra said:
You can do that? That is sweet....
How 'bout in cubase?
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just record a track's worth of hum onto a separate track, and flip the phase/polarity of it. it should cancel out the hum on the tracks where there's actually guitar.....


cheers,
wade
 
mrface2112 said:
just record a track's worth of hum onto a separate track, and flip the phase/polarity of it. it should cancel out the hum on the tracks where there's actually guitar.....
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Woah! That will only work if the inverted hum and the hum on the recorded tracks are lined up to be 180 degrees out of phase. Put another way, the hum on the recorded tracks has to have identical zero crossing points as the hum on the inverted track. If not, not only will the hum not be cancelled, but even more noise will be introduced.

Plus there's the added complication that if you have multiple recorded tracks of guitar with the hum, chances are far more likely than not that the hum will not be in phase between those tracks. This would mean, using the method described, that you'd have to create one hum track for each seperate guitar track and line each one up accordingly to be exactly 180 degrees out of phase with each other.

Finally, using such a method you'd have to make sure that the amplitude (volume) of the hum on each track pair was identical, otherwise the hum will not totally cancel out.

Much easier and cleaner to just beg, borrow, or steal another amp or use amp modeling. ;)

G.
 
SouthSIDE Glen said:
This would mean, using the method described, that you'd have to create one hum track for each seperate guitar track and line each one up accordingly to be exactly 180 degrees out of phase with each other.
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you're 100% right, glen. it's a MASSIVE pain in the ass. :D

but it's an additional option. :D

FWIW, i've done this with some marginal success in the past. it's ugly, but you *can* make it work.....

SouthSIDE Glen said:
Much easier and cleaner to just beg, borrow, or steal another amp or use amp modeling. ;)
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i would whole-heartedly agree.....but he didn't seem to be receptive to any of them.

and since all of the "simple" solutions had been given.....we all know that when in the middle of desperation, sometimes the absurd seems perfectly reasonable. and since none of the simple solutions seemed to be satisfactory.....why not provide an absurd one? :p


cheers,
wade
 
There are many good suggestions. Harvey and grn have the two techiniques that I use most often. My pickups need to be 90 degrees in relation to my amp...even if I'm 20 feet away. Also, ramping the level down in the mix will help.
 
mrface2112 said:
just record a track's worth of hum onto a separate track, and flip the phase/polarity of it. it should cancel out the hum on the tracks where there's actually guitar.....
Click to expand...
I would second SouthSIDE Glen's warnings here. I don't know how it works, but in Cool Edit, it created a noise profile if you gave it a few seconds of the hum. Then you could select a track or portion of a track and apply a filter using that noise profile. You could also select the strength with which you wanted it applied (higher strength more noise removal but also greater chance of artifacts).
 
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