Top Tip recently discovered for those using Oppo 203/ Oppomod i2s boards with their DS

This was a cool find… :slight_smile:

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 .

wordy version…

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. :slight_smile:

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.


Hello, I am considering doing the oppo mods to my udp 203. Have any of the mods affected the video playback performance of your oppo? Thanks

The mods collectively improved the picture quality by quite a margin.
Already the stock 203 was top class, the mods took it to the next level up.

Honestly, the difference between a 4K Blu-ray and a 4K stream of the same film is really obvious.
Sharper image, deeper colours, better saturation…far more natural movement and flow.
It can’t be far from reference level.

Which mods affected picture quality in particular?
I felt fitting a linear power supply, the silver power Furutech iec inlet and the silver ribbon cable from power supply to main board had the most effect.

Fitting a faster clock to the Oppo also tightened everything up.

I’d say to anyone, do ALL the mods…even if it takes some time to spread the cost>
It’s a superb machine that has a lot of untapped potential from stock form.

That’s why PS Audio and MSB based their transports on it.
Hope this helps!

Thank you for the speedy reply! I love my oppo but was never crazy about the 2 channel playback. Its not terrible but its not great. The price of the 205’s after Oppo ended production is ridiculous so I purchased a Marantz Ruby SACD player/Dac floor model at a great price. The Ruby is a big improvement over the Oppo for 2 channel and SACD playback. I think if I do the mods to my Oppo and get a PSA DSD it will surpass the Ruby in performance and I can sell the Ruby.

As far as 4K Bluray vs streaming I agree the disc are far superior in sound and picture quality tho streaming has come a long way!

The Oppo is the Swiss army knife of my system. It functions as a video switch, video scaler for my 2:35:1 movie screen and lens plus its normal duties as a 4k Bluray machine! If I can bring it back into the 2 channel system I will be one happier camper!

A couple last questions for you. Does the I2S board use the existing HDMI out? Or does it add an extra connection? Do you lose any functionality of the factory HDMI outputs by adding the board?

Thanks again, Paul

Hi again Paul.

The i2s board uses its own HDMI, completely separate from the Oppo ones.
No functionality is lost, basically the i2s board acts on its own.

The i2s board takes its power from the Dac board supply, but You can “daisy chain” the existing Oppo Dac board too, so you have functionality for both.

If you can use the i2s out to your dac, you wont want to use the inbuilt Oppo Dac…trust me. :slight_smile:

I’m assuming you’ve seen my Oppo 203 mods thread here?�m-about-to-do-Major-Oppo-mods

I did see the thread which has helped out a lot in driving my decision. I did not see anything about installing the I2S board. is vague on the instructions. Are you just unplugging ribbon cable and attacing it to the new board? Is there any soldering involved? I did see a necessary cutout for the I2S port. Thanks again.

Hi Paul,

Just took a look on Oppomod’s instructions for the i2s board.
He’s paying attention hes used one of my photos! :slight_smile:

Take a look on Page 12 of my thread�m-about-to-do-Major-Oppo-mods/page12

Cut the required slot of the HDMI socket which will stick out the back of the 203 (I used a Dremmel, so protected the inside of the player with paper - important!)

Mount the Oppomod board to the back panel using M3 machine screws (supplied?) making sure the i2s HDMI socket is properly placed in the hole.

Carefully disconnect the blue ribbon cable from the Dac board that connects to the Oppo’s main board.
( You use this same cable to connect to the i2s board)

As per my picture, carefully connect that to socket J5 on i2s card.
From my image you see 2 white ribbon connectors either side of the board?

If you still want to use the 203’s internal dac, use the supplied blue ribbon cable from socket J6 to the same socket on Dac board you took cable from originally.

You should be good to go!
Make sure all connection tight and i2s board bolts are secure on back panel.

#5 connect up, power on and test.

Hope this helps.
Its not difficult, just take your time and be careful not to force anything when connecting the ribbon cables.
It only goes in one way, and will give a reassuring “click” so you’ll know when its in properly. :slight_smile:

Feel free to get in touch if theres anything else.


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Thanks Gary! That was very informative!

Your very welcome!
I can’t praise the modded 203 enough, happy to spread the word when I can.

I could have got a 205 at the time, but my plan was to always use my 4K Oppo as a digital transport Into my Directstream dac for music, so no need for the 205s internal Dac.
Given the video playback gubbins are exactly the same between 203 and 205 I’d save a lot of money!

Also, given all the mods it leaves the 205 behind sound wise…

Let me know how you get on with it all.

Hi Gary,

Did you change to clock on your oppo also? If so what improvements to you get by doing it?
Thanks again, Paul

I did change the Oppo’s clock, both of them actually.
Big improvement in audio and video, though not so much audio via my Directstream, as that Dac ignores the incoming clock.

See my thread…it’s all there! :grinning:�m-about-to-do-Major-Oppo-mods/page18


A little update on the Oppo mods from I installed all but one modification which is the upgraded clock. I was able to pick up a stock Oppo 203 and I’m comparing it to the modified 203. The modified UDP-203 has the Special edition power supply, stabilization plate for the drive, and I2S card. Modified 203 is connected to to DirectStream Sr. with a Audioquest Coffee HDMI. The stock 203 is connected to a BHK Preamp with AQ King Cobra interconnects. I almost forgot how much better the modified player sounds over the stock one. When you compare them side by side the difference (not surprising) is substantial. So if you own a 203 I’d highly recommend the mods! I can’t compare it to other transports but the Oppo/DirectStream duo bettered my Marantz Ruby SAKI player. If you already own the 203 the the complete mods will set you back around $1200 if you do them yourself. I think you can have them installed for $1990 that’s parts and labor.

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The $1990 price also includes a new in the box 203 player if I remember right. I bought one and it is a really nice disc player with i2s output to match the PSA specs.

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Oppo mod complete! Added the Femto clock and Furutech silver power inlet. The sound with the clock and the rest the mods is instantly noticeable and incredible. I compared the sound vs the bridge 2 and the Oppo is definitely cleaner sounding comparing DSD vs. Dop DSD 64 thru bridge. The bridge 2 sounds great but the Oppo is cleaner.

Special thanks to Gazjam for all the info!

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Great stuff Paul,
Glad it’s doing the business for you Amigo.

It’s good innit? :grinning:

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Hi Gazjam, Your post really helped me out, thank you. Like you, I have used my oppo 205 with mostly stock settings, thought the engineers who designed it would know better than myself. I had my settings at PCM/192k because I use a ladder DAC downstream. After reading your post and re-reading the user manual, your post made sense (RTFM). Long story short, using Bitstream settings made a difference for the better. I use a HDMI extractor to get “higher resolution” from the HDMI output going to my ladder DAC. I just wanted to say THANK YOU for the advice. I have not gone down the path of oppo mods yet, but after reading what you had to say, I just might. The only mod I have made is to convert the player to region free. The relevant hypers are attached.

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It’s very good! I do want to upgrade the fuse on the power supply for that last tweak!

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Or do what I did…
And fit a circuit breaker rather than a fuse, you can always go 1 more hardcore. :slightly_smiling_face:

I asked for this to be fitted when I ordered my linear psu, not sure if it can be retrofitted or even the level of improvement.
Not a lot probably.

From experience swapping fuses out elsewhere in my setup, it’s a good way to go.
The SR Orange to match the LPS fitted one would be my choice.

Do it once and do it right.

Great stuff, glad it helped you out. :+1:

I’m looking into the orange fuses. I just missed the buy two get one sale.