sherazkYou can totally use this as an amplifier for your headphones. There is no current gain involved in the pre-amp stage, usually just volume control. My understanding is that the tube in this amp handles the pre-amp stage, while the MOSFET's actually do the heavy lifting and amplify the power.
I am new to this, so any enthusiasts please correct me.
Anyways, the headphone jacks on the front are powered. The RCA Line-Out on the back is line level. From the reviews of the product it appears that the signal goes through the tube before going to Line-Out, which means you can use it as a pre-amp. For example if you have a stereo receiver that's already powering your speaker you would have:
Source (computer or whatever you use) -> Bravo AMP -> Headphones
-in this case bravo will power your headphones
AND
Source (computer or whatever you use) -> Bravo AMP via line-out -> your stereo receiver -> speakers
-in this case bravo serves as a pre-amp, while your stereo actually powers the speakers