I had high hopes in Audio-GD R2R 11. But it turned out to be a disappointing experience and I sold it after two days of ownership
1. In A/B testing, I favored my cheaper Maverick Audio D2 DAC. But it's likely that the R2R 11 needs some breaking-in time.
2. I hear scary noise each time I start playing when hooked up with airport express for airplay. Stop/pause for 10 seconds and resume playing again, scary noise again. It's unbearable. I tried two other different DACs (maverick audio D2 and audio-gd nfb2) in exactly the same setup, other DACs don't produce such noise. I tried different cables, different airport express, different computers/ipads, problem remains. After calling Audio-GD, was told it's likely due to the fact that R2R 11 doesn't have a muting circuit.
3. I tested R2R11 with oppo bluray player. When I connect both optical and coaxial and switch to coaxial on R2R11, my left channel is silent. If I switch to optical on R2R11, no problem. If I connect the optical port to another device and only coaxial to oppo, there's sound from left channel but several seconds delay in the beginning. This doesn't bother me much and I won't use R2R11 this way was just testing.
4. Audio-GD insisted shipping it back to china, but failed to promise to cover the shipping cost. Saying they'll follow their own testing procedure. If it passes the test, I'll have to cover the shipping cost my cost. Well, not worth the time, effort, and risk. I sold it to a local friend who only plays USB.
5. I don't blame Audio-GD. I understand they got many good reviews but unfortunately it didn't work out for me. I then read many reviews about Audio-GD posted in Chinese forums, the reviews are neutral at best. The chinese audiophiles are aware of the reputaton of Audio-GD from overseas but it's defintely not their go-to brand. I was amazed how audiophiles inside and outside China view Audio-GD so differently. Maybe guys in china know many other options in china but we don't.
I personally won't buy again but it may still be a great option for you
I'm going to explore other chinese brands