removing amp hum in a quiet guitar part

Hi all,
 
I recorded a guitarist that had some amp hum (probably a ground loop). Most of his stuff has distortion so it's not noticeable, but he has some parts he plays cleen and more quietly and I would like to remove the hum. I looked in my plugin arsenal and it doesn't appear that I have any noise reduction plugins.
 
Any suggestions? Is there another way to do this, or is there a plug-in I should consider?
 
thanks!
 

Thanks bats - I'll give it a shot tonight!

That's what I suspected. Probably best to use a Linear Phase EQ then...

Audacity has a noise reduction function.  You select a small area that contains just the noise you want to remove and audacity removes it from the entire track.
 
You could pre-process the guitar track with it.
 
 
Bare in mind when reducing mains hum with a filter that the fundamental (50/60hz) is not generally what you hear. It's the distorted noise/buzz being modulated by the 50/60hz hum.

Sonitus EQ has a 60Hz hum reducing preset. An FFT noise reduction tool might produce a better result. This is the type of tool described in Audacity. Another free one is the 32bit version of ReaFir part of ReaPlugs. This one looks interesting but I have not tried it. So does this from the same site, specifically designed for hum removal. For fee an editor such as SoureForge has an FFT noise reduction tool and some of the iZotope RX tools. Then there is the full version of iZotope RX which provides a more comprehensive set of tools.

All good advice so far, to which I'd add:

De-humming guitar (or anything else) is often best achieved by combining several tweaks in moderation rather than a single, powerful one. Broad-band hum is harder to get rid of than a mains-only one, and induced noise caused by a PC or lighting dimmer can be particularly difficult to counter in the mix. It's generally better and easier to tackle the noise at the source than remove it later. Often simply moving the guitar somewhere else in the room, or even the guitarist facing a different way can lower the noise floor. As can a change of guitar lead (and the shorter the better). And make sure the guitar's string earth is working properly.

However, once the noise is tracked it has to be minimised.

So:

High-pass with a steep slope at around 85Hz.
Watch for noise at multiples of the mains frequency, particularly the first couple of octave harmonics around 100/120 and 200/240Hz depending on your local mains AC frequency. Reduce the noise with narrow band eq as far as possible without the eq wrecking the overall sound.

Careful, gentle use of a post eq gate/expander can work wonders.

Consider lowering the volume of the track until the hum isn't objectionable then build the rest of the mix around that. With any luck once the entire mix is then brought up to final master levels any residual hum on the guitar track won't be noticeable.

If all else fails, if the problem is mostly noise in the gaps between guitar notes, especially if th guitar was recorded with no or minimal reverb it is possible to go through the audio, chop it up so the noisy gaps between notes are isolated then reduce the noise-only clips to silence with a bit of a fade-in and out, if necessary gently shortening reverb tails as needed. It's a slow, painstaking job though.

Only apply any form of noise reduction in the areas where you can hear the problem. Leave the rest alone. Noise reduction can alter the sound to some degree as well. If you cannot hear it then leave it alone! You will find there are only a few areas where the noise or problem is audible.

3618hz is not what i would call 'hum'.

Bats - perhaps hiss or sizzle would have been more accurate than hum. :) At any rate, thanks for the advice - the LEQ helped.
 
Thanks for the chart tlw, that could prove to be very helpful...