Quote Originally Posted by Guitargodgt View Post
I use a Rane HC-6 and it's loud... to loud. But to be honest I would rather have way to much on hand gain than not enough, but to be honest I think I would blow out my headphones if I ever turned it up all the way. It's painful to me past 12 o clock (seriously).

My interface has 2 headphone outputs, and they are nowhere near as nice or have even a quarter of the output gain of the Rane.

That said, while yeah I could hook up headphone mixes with it, I don't because I have not found a situation where it was needed to date. There are TRS stereo inputs and outputs for every channel on the amp however I don't use them and every channel out is the same master stereo input.
Rane give a very comprehensive table of the power into phones of various impedances. Something I have not seen any other cans amp mfctr do, BIG props to Rane!
Rane suggest that these maxima will deliver some 120dB into most common headphones, a level you should not experience for more than a few seconds and some phones, e.g. my K92s would probably exceed even 120dB. Some sums get me a likely output resistance* for the Rane amp of about 15 Ohms. This is at least 1/2 the OPR for most H/P amps but I can see their logic for a "professional" device. I am very pleased to see they have not gone the (daft IMHO) route of claiming a zero OPR is needed for "proper" headphone reproduction. Such a low source R is, IMHO both compromizing to the amplifier's design and potentially dangerous to the users hearing.

*Not "impedance", usually a pure, phyisical resistance.