Input hum question...

[sgoodwinca]

Hey folks, quick question: I have two acoustic/electric guitars with active pick-ups. With a 1/4" input into the MBox, one is perfectly quiet, but the other causes a god-awful hum. I can stop the hum by physically touching my computer and grounding myself, but this is not very practical.

Is there a fix for this and is there a particular kind of 1/4" jack cord which wold be optimal (i.e. balanced vs unbalanced, etc).

Thanks and sorry if this is n00b-dumb.

Cheers,
Simon

[albee1952]

Not dumb at all. I would say the humming guitar has a problem, or a crappy pickup system in it. The vast majority of us that record acoustics, do it with microphones If you just need to get parts down, maybe install a new pickup in the bad guitar(even a sound-hole model). Also, with the humming guitar in record-ready(so you can hear the hum) move around, move away from the computer, and try rotating your body to face in different directions. With my electric guitars going direct, its amazing how turning a certain way will cut the hum by 70%.

[sgoodwinca]

Awesome thanks

[Darryl Ramm]

What exact pickups are in each guitar? Especially are each magnetic or piezo? the batteries fresh in both? Besides the noise is the signal level seem appropriate? Check the string grounds are working properly and connected to the instrument cable shield.. or if the guitar has grounded strings at all...

Almost all Guitar pickup connections are unbalanced. There is no point in using a balanced cable since the signal source is inherently unbalanced (unless it's a humbucker but even then they just cancel the noise at the guitar, no point in carrying both phases back to the DI/preamp) and a huge amount that noise is always going to be picked up in the magnetic pickups not the cable (even for humbuckers or 'noiseless' pickups).