Primarily use the Oppo with optical media to drive the headphones. The DAC chip is a 32 ESS 9018, if I recall.
Occasionally also use a Sony UPB X-1100 ES to drive the headphone amp. The Sony doubles the sampling rate of CD/DVD/SACD for two channel to improve audio quality. Honestly, it's difficult to say that one player drives the headphone amp better than the other. They both sound very good.
The players both support you tube streaming, and the Oppo also supports the Berlin Philharmonic app.