Greetings everyone. I'm perhaps the newest member of the Vali admiration society. I ordered mine directly from Schiit on a Friday and received it on Saturday ( How is that for service?) 
 
I'm rather new to headphone amplifiers and my only means of comparison is a A / B test with a Bravo Audio Ocean that I have had for a few weeks. So far I hear little difference between the two. That is not a bad thing as I am very pleased with the little Class A Bravo Ocean. The cost of each amp is nearly the same and each have slightly different features. But a sonic comparison reveals very little difference. At least so far.
 
I'm listening with a pair of Sennheiser HD 598s and one of the things I have noticed is that the Vali has a lower output as compared to the Bravo Audio Ocean, when using the same line level input. My input is currently the variable output of my TV / monitor as driven from a Roku box. I'll be trying a fixed level line input this week and I'll also probably be updating to a Schiit DAC in the near future.
 
I'm doing a little experiment. I'm driving the Vali using the preamp outputs of the Bravo Audio Ocean. This allows me to achieve loudness levels that I will seldom exceed, and both units have their gain controls set to no more then the 12 o'clock position. 
 
Update: I've connected my Vali to the fixed output, line outputs of my CD / DVD player, and my concerns about the sensitivity / output of the Vali are  unfounded. It produces a clean, ear shattering signal with the gain control just past the 12 o'clock point.  
 
I'm currently listening to Dark Side Of The Moon and I'm hearing things I've never heard through my SS Integrated Amplifier.
 
I give this little Vali my highest praise. That is, I'll be purchasing more Schiit based on it's performance.