Seems like my Mbox 2 at home has output problems. If balanced 1/4″ M – XLR M cables are not used, then there is considerable hiss and squealing, especially with phantom power on. I was originally using regular mono 1/4″ speaker cables, but those problems were the result. I’ve noticed that the problem gets worse when Pro Tools is actually opened, which is strange; why would certain software (since it doesn’t occur with other programs) exacerbate a hardware problem? Regardless, this has occurred in the mix benches on campus, so perhaps I can look into swapping out some cables in those studios.