Recording Grounding Issues

[Alex Normanton]

Hi there,

I have recently bought a FocusRite 2i2 and using with a MacBook Pro.
I have x2 guitars: 1 Fender Jazz Bass (recently rewired) and 2. Takamine EN20.
I'm processing both of these instruments through a FocusRite Audio Interface into GarageBand/Ableton.

I have an annoying buzz on the line input which does reduce when the power cable is unplugged and also the wire to my monitor.
I have tried various things:
1. Upgraded cables: line input
2. Rewired bass
3. Changed laptops
4. Changed Focusrite
5. Ran the guitar through a D.I with ground lift turned on

I still have issues...
Please help...

 

[filmtex]

I would try a power conditioner like this Furman. Not only is it something you can use in the long run even if it doesn't solve this particular problem, but the odds are in your favor that it will. Also, I would double check the wiring job you did on Jazz, just to make sure that something doesn't still needs attention or perhaps changed when you reinstalled everything. Thirdly, I'd try a different feed to the monitor, just to make sure it wasn't the cable itself. Good luck.

 

[BrianVengeance]

It sounds like you may have dirty power and/or RF interference. As flimtex mentioned, a power conditioner (or running off of battery power for everything) can help with dirty power, or it may be something with the wiring in your jazz bass. The preamp on the Tak may also be noisy when cranked up a bit. I have a Michael Kelley acoustic bass with a preamp that isn't terribly well behaved.

Some troubleshooting thoughts:

What happens if you move into a different room or plug everything into a different outlet?
Does your rewired bass play quietly through an amplifier?
Does the amplifier also make nose?
What if you turn off lights? (they could be a source of RF interference)
Are your cables shielded?
Is your interface set up for using an instrument input with the Jazz?

Also, if you can post a recording of the noise, it may help to troubleshoot.

 

[seamonkey]

Hardly ever is it dirty power.
It is probably shielding on your basses. Not rewire - shielding, as in make sure there's copper shielding and it has a single ground connection to it like a "star ground".

Since you noticed it from the monitor, move away from the monitor or it could be something in another room your bass is picking up noise from.

Is it mainly just noticed when you solo? It may not be audible in the mix.
It's best to address the hum before it gets on the track but if you don't have time to keep messing with it ...
There are many plugins that filter out hum
The old trick done by studios decades ago was to record one track of hum with harmonics. Then mix this in to null out the hum. It's just done with software these days.