[PurpleAngel]

  After listening to this amp for about a week plus, I have a few question I was hoping you all could help me with. My typical configuration is to use TIDAL on my pc as a source, plugged into the E10K, with the line out to the line in of the Bravo Ocean, and listening through DT990 250 ohm cans.  Usually I have the volume on the PC turned to max, and the volume on the ocean at near 0.  After listening for several hours a day, on day 3 I think I was experiencing some ear fatigue. I've never experienced that with the E10K alone.  Could the sound out of this amp be irritating my ears? Then today, I decided to turn the volume down on the PC to about 6, so I would have a bit more control with the volume on the Ocean.  Turning the volume down on the PC and up to about 25% on the Ocean seems to sound better and different somehow, but I couldn't put into words how.   The other odd thing is that using the Ocean, it seems like I need to keep the volume much lower than when not using it.  It's as if there is just more sound coming out of the Ocean.  Not louder sound, just more of it. It's difficult to describe, but I'm hoping someone will be able to give me some insight into whats going on here.  So here are my questions:
 
Can I cause distortion through the Bravo Ocean if my PC volume is at 100%?
How likely is it that this amp, headphone combination is causing me some fatigue?
Would a different tube help? (can't get new cans just yet)
Does it make sense that the Bravo Ocean is putting out more sound than another output device when set at the same listening volume?

 
If your ears do better with the PC's volume level set to 60%, cool.
Could be the Bravo just drives the DT990 better when the Bravo outputs more voltage?

 

[Me x3]

From a technical point of view is slightly better to leave your PC at 100% and set the volume with the amplifier.
The thing is the Bravo might have too much gain for your DTs and your preferred listening levels, then you might end up listening to music at louder levels and that's probably causing fatigue.
 
That's why most amplifiers (including the E10K) have Gain control.

 

[Slurry]

Over the weekend I figured out what all the weird ear strain was comming from. Between the E10K and the Bravo Ocean I had a very cheap flimsy stereo cable. Replacing that cable with a stereo to RCA Cable that had a bit more heft to it solved my problem. The flimsy cable works fine with the portable speaker it came with, but for some reason, using it between the E10K and Bravo Ocean was causing some type of distortion. I haven't narrowed it down to the cable itself or the line in port of the Ocean yet. For now I'm just glad to be listening fatigue free.