I received my Valhalla 2 this morning and have spent the last few hours listening to it. It's a clear improvement over the Vali in terms of soundstage, clarity and instrument separation, while exhibiting less mid-bass bloat. My HD650s now sound more dynamic and engaging.
I'm generally quite pleased with it, but there's one thing that's puzzling me: it actually seems to be slightly quieter than the Vali at a given volume setting. For instance, there's one quietly recorded song that I would have normally listened to with the Vali's volume pot set at the 11 o'clock position. I have to push the Valhalla 2 to the 12 o'clock position to get a similar level of loudness - and this is with the gain switch set to the high position. According to the specs posted on the Schiit website:
Vali: Maximum Power, 300 ohms: 220mW RMS per channel
Valhalla 2: Maximum Power, 300 ohms: 800mW RMS per channel
One would infer from this that the Valhalla 2 should in fact be far louder than the Vali at a given volume setting. Does anyone know if there's a simple explanation for this, such as the tubes requiring burning-in? I hope I haven't been given a defective unit.