Oh man, I've always wanted to listen to the Sonett!  Hopefully it will work out.

  I don't know if anyone is already bringing one, but I'd definitely be interested in listening to Vali 2.

I haven't made it to the last few of these, so I'm definitely going to try to make this one.   Quote:   I have X2s, and I'll definitely bring them if I can make it.   Gear for those interested:   Senn HD598 Fidelio X2 Modi Vali

This could be a good place to start: http://www.innerfidelity.com/content/innerfidelitys-wall-fame-full-size-sealed#GqG2vIBkqDHZw0QE.97   Other than that, you may consider IEMs or CIEMS.

PS4 works with USB DACs, so really anything should work.

I've always been curious to hear McIntosh gear. It will be interesting to see how they handle a headphone amp.

I don't think it's that bad of a disparity. You have the HD650, all he Audezes, the Oppos, and Shure and Westone iems, just to name a few. They're out there, but I'll agree, definitely in less numbers, and usually at higher prices. I think the trend towards bright comes from the perception that...

  Just on my experience with Grados and Vali separately, I think it probably would be a decent match if it wasn't for the hiss being made worse by the Grado's high sensitivity.  Of course, I'm just speculating here.   Honestly, if you want a good tube amp that works with your cans and allows...

I agree. I've owned both, and X2 is very similar to the HD600, except with universally better bass, a touch more forward presentation, and better top to bottom balance. A good upgrade IMO.

A few to consider: Koss Ksc75 Senn HD600 Philips Fidelio X2

As above, try it without the splitter. If that doesn't solve it, check volume and setting on your computer. Then check the Schiit trouble shooting faq. If none of that works, you may have a defective unit. It happens, call Schiit, and they should sort it out.

Innerfidelity has a few comparative reviews of both TOTL and budget CIEMs. That might be a good place to start.

  Everyone knows 560s only start to open up at 123dB, and need a minimum of 50 watts per channel.              

  Vali is pretty nice.  Works well with plenty of headphones, gives a nice touch of warm, but can be a little noisy (low level hiss) and others have found it microphonic (not my experience).   For the price, I think Vali is a steal.  Definitely worth considering.

The Schiit Gungnir is a pretty good DAC in my experience. With USB it goes for $850.