Thanks to Zach for lending me this thing! I like the Battery DAC overall but probably not enough to buy one. Here are some observations after using it at work for a while with my X3, Cayin C5, and TH600.
It is less colored than I was expecting. I don’t notice any loss of detail compared to the DAC in the X3 (note that I listen mostly to electronic recordings where you’re not going to hear people breathing in the audience or whatever). The treble is rolled off somewhat but I’m fine with that. The bass has an interesting character that I can’t quite put my finger on… Compared to the X3’s DAC, I’m hearing more subbass and less midbass. Impact is decent but there is less body in a way. Punch is lighter, airier. Rumble and extension are good. Soundstage depth and width are respectable but it has a more cohesive (vs layered and separated) presentation.
But the main thing I notice about this DAC is that it has a softness to it. Maybe you could call it politeness, smoothness, richness, etc. It’s very unfatiguing and easy to listen to, but it lacks some bite and excitement. I find myself listening at louder levels to compensate. The synergy with my TH600 is good. It evens out the V-shaped signature and smooths the treble considerably. I thought it sounded too soft and syrupy with my HE-400i. Very lush though. I believe someone in this thread compared it to a cheap tube amp. IMO that comparison is OK—the softness is kind of tubey. However, this DAC doesn’t sound slow or thick to me. The bass is reasonably tight and controlled.
Compared to my Audio GD DAC 19 (also R2R), it’s really no contest. The Audio GD has more presence, body, energy, clarity, refinement, while being just as easy to listen to. That’s what I really look for—I hate gear that hurts my ears but I don’t like too much softness either. Beyond my preferences, I don’t have anything bad to say about this DAC. It sounds nice. Worth considering for anyone who wants to tame some bright headphones, especially if you don’t listen to aggressive music.