“Any suggestions for a warmer digital sound”
Have you tried putting the Oppo in the microwave?
A more fruitful approach would be to use an external DAC, and personally I would recommend on the does not use an ESS Sabre chip, as does the Oppo. My Oppo 105 sounds much better as a transport into my Bryston DAC3, which uses AKM manufactured chip. ESS have fantastic detail retrieval but can sound harsh. I had another DAC featuring the same chip as the 105, a Mytek Manhattan, and it offered different filter options, but none of them seemed to tame that fierce treble (my speakers are B&W 803D, and those diamond tweeters can be to much of a good thing, particularly with solo Piano). At any rate, DACs sound different, similar to variations in turntables and phono preamps. Try something else.
Have you tried putting the Oppo in the microwave?
A more fruitful approach would be to use an external DAC, and personally I would recommend on the does not use an ESS Sabre chip, as does the Oppo. My Oppo 105 sounds much better as a transport into my Bryston DAC3, which uses AKM manufactured chip. ESS have fantastic detail retrieval but can sound harsh. I had another DAC featuring the same chip as the 105, a Mytek Manhattan, and it offered different filter options, but none of them seemed to tame that fierce treble (my speakers are B&W 803D, and those diamond tweeters can be to much of a good thing, particularly with solo Piano). At any rate, DACs sound different, similar to variations in turntables and phono preamps. Try something else.