Mbox Whines with External devices.

[hue]

A cut and paste from another thread:

I noticed that when plugging an external preamp into my Mbox 2 Mini(yes, I'm cheap and poor and...foolish). At any rate, I've tried two different preamps and both had the same result, a high pitched whine even with no signal passing through, all gain down.

My other, "cheaper" (Mackie Firewire) interface had no issues whatsoever.

I finally decided to try using the pad switch on the Mbox. Well, it's a huge improvement. Even when the monitors are cranked there is hardly any noticeable noise. The whine isn't gone mind you but it's considerably better. Not at all noticeable at normal volumes. Of course this is still an issue if you are using an external preamp that doesn't have a lot of gain.

I don't have this issue when I plug in my Tonelab. Only when I use an external preamp. And, yes all the cables are balanced. I still think it's a ground issue but within the Mbox itself. Direct monitoring has no issues just when monitoring through any DAW(I also use Samplitude SE).

Why have line inputs if they are unusable? Apparently I am not the only one with this issue. I don't know this for a fact but I've heard.