I'm pretty sure by the sound alone that it's an A1. The A2 I had sounded dry and a bit cold to me. This one sounds normal tonally but just as resolving. I don't really care about the minute subtle improvements in DACs beyond that. Transducers do so much more. I still don't understand everyone's flowery language about differences in DAC's when they're using such colored, resonant, distorted headphones. Makes no sense. But the tonal difference between A1 and A2 is obvious to me and a big deal.