This was a cool find…
Quick n dirty version:
Switch off any conversion/ upsampling in Oppomaudio settings to pass an unaltered bitstream to the DS dac to better let it do its magic .
Use my Oppo 203 with Oppomod i2s board directly into my DS Snr.
Always looking for tweaks to improve sound quality, and discovered this one by accident.
I’ve mostly used the Oppo’s Auto settings as I trust their engineers know more than I do about optimising their player.
Watching a movie through the big rig late last night and being the neighbour friendly chap I am, kept the volume at a decent level.
Was hard to hear quiet voices though, so went into the Oppo audio settings and switched on Dynamic Range Control which brought out voices a lot better at lower volumes - cool.
This morning listening to music I felt it sounded a bit flat sounding, then remembered I’d switched on DRC last night in the settings.
Switched off and my music was back.
Wondered about why though, as my audio is passed through the Oppomod i2s card into my dac, not from the Oppo DACs or HDMI output itself?
Curious thought I…the circuitry chain before the Oppomod card affects the output of it’s i2s output…
Coming from an ex Music Server business point of view, and putting that hat on for a second, I got to thinking.
Back then it was all about minimising background processes and keeping the signal path as untouched as possible.
So was there anything I could tweak in the Oppo’s audio path to better protect the signal path coming from my Roon server to the Oppo i2s and eventually to my DS dac?
Tuned out yes there was.
In Oppo’s settings, under Audio Output Setup, there’s an option “HDMI Audio format”?
Shouldn’t be relevant as I’m not using the Oppo’s built in HDMI sockets, but the Oppomod board.
The setting here to chose LCPM or Bitstream (Where you tell the Oppo to decode the incoming bitstream to OR PASS IT UNTOUCHED TO AN AV RECEIVER TO DO THE DECODING) is relevant.
Setting to “Bitstream” switches off the Oppo from touching any incoming signal and passes it direct and untouched to the i2s card.
When set to LCPM there is a layer of processing to convert to PCM before the signal gets to the DS dac, where there is another conversion.
Setting to Bitstream removes a layer of processing and lets the DS better do its thing.
Sound wise, music has more space to breath, flows better and therefore more musically engaging.
The extra layer of processing added some mush to the signal entering the dac, removing it makes things better.
Not night and day, but it’s missed when it’s not there.
Wanted to pass this on, hope it helps someone.