Simply amazing product, wide separation, deep, and detailed. While playing symphony and opera, space presented deep and nice. All my digital music burned in FLAC format and played even better with this tiny optical dac. Love it and highly recommended.
The DAC is flawlessly neutral, clear, crisp and clean, just as it should.
My full review can be found here: http://www.head-fi.org/products/hifime-spdif-optical-9018-dac/reviews/16096