Hiss, Hum, Bad Earth And 120 V's 240V!

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JosephDignamMusic
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Hiss, Hum, Bad Earth And 120 V's 240V!

Post by JosephDignamMusic » Tue Apr 08, 2014 6:52 pm

Hi All,

Just a quick question on any techniques that people are using to eliminate or reduce audible hiss and hum in recordings.

Trying to band aid fix it after the recording is proving impossible and I'm not seeking a magic wand fix... Currently using an iRig Pro as my input interface until my focusright Scarlett arrives but the iRig for what it is is actually pretty faultless.

I do have a an undiagnosed bad earth issue in my music room where all of my guitar inputs will hum, which can be reduced slightly once my hands are on my strings or my foot is resting on the metal body of my loop pedal. Beginning to become very annoying and process of elimination with cables etc is proving inconclusive!

I totally understand that any "dirty" input is always going to be near on impossible to fix after the fact but any suggestions would be appreciated.

Also, another query on the 50 hertz when describing hum. Is this frequency typical in all electrical circuits or only 120v circuits (eg: USA)? I am in Australia - (240v)

Sorry if this is a frustrating and amateur question for the pros out there...

Joe

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sodium
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Re: Hiss, Hum, Bad Earth And 120 V's 240V!

Post by sodium » Tue Apr 08, 2014 8:23 pm

You could try a smart EQ/noise filter that will "learn" the problematic buzz frequency and then you could incrementally cut that frequency in the really problematic tracks. But you're right fixing it in post is always going to be less than optimal. As for your bad earth issue, have you tired ground lifting it thru a DI? something like that might help. Also if you're using CRT monitors or light dimmers these are infamous buzz generators. Australia is on 50khz mains.

Good luck, but more importantly find that earth/ground problem !

Cheers,
na
"get down off that cross we could use the wood..."

JosephDignamMusic
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Re: Hiss, Hum, Bad Earth And 120 V's 240V!

Post by JosephDignamMusic » Wed Apr 09, 2014 12:37 pm

I think I fixed it! :)

mrufino1
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Re: Hiss, Hum, Bad Earth And 120 V's 240V!

Post by mrufino1 » Wed Apr 09, 2014 5:37 pm

Please share how, i have some difficult 60 cycle him in my house at times.

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sodium
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Re: Hiss, Hum, Bad Earth And 120 V's 240V!

Post by sodium » Wed Apr 09, 2014 11:22 pm

JosephDignamMusic wrote:I think I fixed it! :)

Hey how about letting us know how, please?
"get down off that cross we could use the wood..."

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martygras
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Re: Hiss, Hum, Bad Earth And 120 V's 240V!

Post by martygras » Thu Apr 10, 2014 3:27 pm

I run everything in my studio of of one 15 amp outlet. This eliminates about 90% of all problems I used to encounter. I've had to run entire rock bands live off of one outlet (inlcuding FOH mixer) without a problem. First time was at an outdoor event where I was crossing my fingers the whole time. That was whacky.
I also make sure any wall wart's cables are NOT neatly coiled. Coiling power cables causes an induction field that results in a hum that is different than 60 cycle hum.
Some hardware synths/laptops/amps cause hum due to whether they have a ground or not so I use an Ebtech Hum Eliminator. Beware, all hum eliminators are not equal.
Marty Schulte [I'm a drummer. So, there's that.]
iPad AIR(128), Akai EIE, Akai EWI USB, illudium q-36 explosive space modulator
Head First Audio (live sound for Southern Oregon, USA)

dominicperry
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Re: Hiss, Hum, Bad Earth And 120 V's 240V!

Post by dominicperry » Fri Apr 11, 2014 4:14 am

UK - 240v, 50Hz
US - 100v, 60Hz

The most likely cause of hum through guitar pickups, (usually single coil) is flourescent lighting and CRTs. Or a poorly shielded guitar.
Fixing it in the mix is useless, if it's loud hum. If it's only noticable when there's no playing, then volume/mute automation is useful.
Advice to run everything off one socket is potentially dangerous - you should check to see what your load is. For small studio equipment, it's probably fine. For a bunch of PA amps, it's a bad idea.
Likewise, advice to lift the earth on some equipment is potentially dangerous. You need to be sure everything which should be earthed IS earthed. People will tell you not to fuss, but most of these people have been shocked at some point.
The best way of isolating audio input from USB hum is to (a) use a decent interface, (b) use a good PSU in your computer and (c) isolate your mic pres and A/D converters from your interface with optical cables.
There are countless articles about studio grounding and hum elimination - do a search for them. If you're using an iPad then the Apple PSU is quite good, but you can always see if hum is reduced by pulling the power cable and running on battery.
Unfortunately most of the interfaces used with iPad are cheap and are less likely to have good isolation. RME stuff is always good.

Dominic

JosephDignamMusic
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Re: Hiss, Hum, Bad Earth And 120 V's 240V!

Post by JosephDignamMusic » Sat Apr 12, 2014 4:47 am

Sorry guys I just meant general noise. My Boss Loop pedal was the issue and so I am trying to find a better quality power supply for it as I currently have cheap multi voltage power supplies - will probably go straight to boss.

I have also just purchased a Furman power conditioner as well - I'll let you all know how that goes.

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sodium
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Re: Hiss, Hum, Bad Earth And 120 V's 240V!

Post by sodium » Sat Apr 12, 2014 5:34 am

Hey Joseph good to hear you found the issue. Do those Boss effects require a regulated PSU? From memory they might.

And Dominic Perry, fantastic post. Comprehensive info re: good studio wiring regimes. 10/10!
"get down off that cross we could use the wood..."

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