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Gary
07-02-2007, 11:59 AM
Hello Everyone,

I just joined the group and the digital recording world. Could someone please give me a starting point for removing guitar amp hum thats on the track? Not looking for a detailed step by step, just a starting point would be great. Thanks.

Gary

bullshark
07-02-2007, 12:46 PM
Firstly: welcome.

Then for the amp noise you could just gate it, try Reagate, work well for me.

Gary
07-02-2007, 02:15 PM
Thanks for the welcome and the tip.

cAPSLOCK
07-02-2007, 04:24 PM
http://www.musicianassist.com/htf/cheater.gif

cAPSLOCK
07-02-2007, 04:57 PM
As for "ON A TRACK" A gate is a good idea, unless you nned to lose the noise while the gate is open too... In this case you can notch out where the noise is (60, 50, 120, 100 etc... depending on source, country etc. ;) ) Or you can use a FFT NR plugin... I think ReaFIR MIGHT do this, not sure. Waves, and Voxengo make them though....

Gary
07-02-2007, 05:06 PM
Thanks capslock. I'll check into those as well.

Baer
07-02-2007, 05:12 PM
For noise already recorded, Sonic Foundry‘s noise reduction product may be useful -- it has been included with the last few versions of Sound Forge. There are other similar products available.

As for preventing this problem in the future, the three-prong-to-two-prong converter may work but is not advisable for use on guitar amps or anything you plug your mics into. Putting yourself in the middle of a severe grounding problem could be hazardous to your health. (I must admit that I use one of these converters on a Dell laptop, though.)

If your hum really is ground loop related, a better solution (if you can spare the $50) is an Ebtech Hum Eliminator. It won’t help with noise other than ground loop noise, but for that application, it works wonders. And again, there are other similar products out there.

cAPSLOCK
07-02-2007, 05:51 PM
*IF* and I mean ***IIIIFFFFF*** your problem is actually being caused by an honest to goodness GROUND LOOP then your amp is still grounded when you lift the ground to power.

The reason is the amp is getting ground both through it's power line, and some other devices power line.

For example... if you are going in or out of the amp to a mixing board or another amp, then you are sharing ground with THAT device.

But ground loops are not the ONLY cause of hum. And if lifting the ground doesn't solve the problem then your problem is somewhere else and you should immediately replace the ground to power.

Gary
07-03-2007, 05:25 AM
Thanks for the info. Its nice to find a forum where people actually reply to your posts.

sinkmusic
07-03-2007, 10:47 AM
Reafir is supposed to help you removing hum. Read the Reaper's manual, you'll find out how to use it.
Else, Acon Acoustica is rather cheap and can do noise reduction in a quite effective way.
The old Cool Edit 96 is very effective for that task, you should be able to find it on the web (the demo is restricted to 2 kinds of operations).
Then, Elevayta plugins could be efficient for that, or you can try a very good eq (like ELectri-Q), but spectral stuff is better for noise removal.
The Waves plugins or Waves Art have a good reputation, but they are very expensive.

tspring
07-03-2007, 01:00 PM
Its always a good idea to try to deal with electrical noise by eliminating the noise sources or to shield to prevent noise pickup. Filtering it out in Reaper should be a last resort.

I pre-apologize if the following suggestions are too obvious or OT.

It you are hearing 60 cycle hum, your guitar amp's power supply might have a problem, best handled by a tech type unless you are really competent with electronics.

If you are hearing a buzzing sound that varies as the guitar is being moved around, then the problem could be poor shielding of the pickups or poor grounding of guitar strings. Lots of info on the web for dealing with this.

Fluorescent lights, dimmers, and solid state power supplies (especially for Dell laptop PCs) all can play havoc with your recordings and generate all manner of whines, buzzes and humms that are transmitted as radio frequency interference. You can use your guitar as a detector to find noise sources(noise gets louder as you get closer to source). Eliminate all noise sources you can. I knew one fella who was being driven nuts by a phantom noise source. Constant buzz from his guitars. Turned out to be an old doorbell unit that no longer worked, but which was buried in a wall and still powered up. I once had a video monitor that had to be turned off during recording - I couldn't get far enough away to prevent my guitar from picking up noise from it. LCD flat screens seem much less prone to generating noise, probably cause they work at much lower voltages.

T

Gary
07-04-2007, 04:51 AM
I've been playing around with the Reagate and Reafir and getting most of it out. Thanks again for the info.

Gary

Yaz
07-06-2007, 05:03 AM
Me thinks in our little home project studios, the best money spent would be to purchase line conditioners to eliminate RF frequencies in the AC lines.

Yaz
07-06-2007, 05:16 AM
Just a footnote, Furman has power conditioners from $60 and up. Filtering RF frequencies and voltage surge protect in one unit! The garage band I jam with had amp buzzing and pops and clicks (flourecent lights in building) in amps until we purchased 3 of the lower priced Furmans. Now we have zero noise in the amps. If we could just play worth a crap, we'd be in there!

Baer
07-06-2007, 08:57 AM
Yaz -- good point. My equipment is always powered through a conditioner. I use three of them in my home studio. I see the Furman PL8-IIs on Craigslist here in San Francisco periodically for about $100 which is a very good deal. Unlike other surge protectors based solely on MOVs which are slowly consumed by power surges, the Furman (and other) SMP-based units will last forever (an exageration to make the point).

They won't, however, so anything for ground loop problems and RF issues within pieces of equipment. I have a Carl Martin compressor that is a wonderul unit except in my home where it acts like a radio receiver.

Yaz
07-06-2007, 01:39 PM
Good point Baer, that's when placement of the unit,power cords, guitar cords, patch cords etc, can help. But can be a bear to find. Coiled up electric cords can become like a transformer with heat and can produce annoying zits in sound. Running power cords parrell to guitar chords can cause build up. So many factors in laying out a home studio. Plus room space, such in my case is a factor also.

fluffy
07-13-2007, 04:06 PM
ReaFir is your friend here.

Place ReaFir on the guitar track. Set it to "Subtract" mode and check the "Automatically build noise profile" option. Now play a segment of the track with the noise you wish to remove, but no actual guitar playing. Uncheck the "Automatically build noise profile" option now, and playback the track. The noise should be gone.

Reafir works quite well in this regard.

Gary
07-13-2007, 05:11 PM
Thanks fluffy, it worked great.

Gary

fluffy
07-13-2007, 06:46 PM
Any time at all.

Justin
07-13-2007, 09:19 PM
I'm very fearful of using ground lift on guitar amps.. well on tube amps anyway..

NathanSmutz
07-13-2007, 10:14 PM
Re: RF interference: I seem to remember seeing instructions for shielding a Rhodes electric piano with tin foil on the inside of it's case. Might one surround an offending wall-wart or other device with grounded foil?