No sound from via HDMI/I2S from Oppo 203 to Directstream


#22

In that case, one could just invert polarity directly from the DSD/DSjr right? Would that be possible?


#23

I think the channel reversal in the next release is delayed until the one after


#24

I’m not quite sure what people are talking about.

The closest thing I can think of is the ability to selectively invert each of the three I2S signals (i.e. Bit Clock, L/R, or data.) But this has nothing to do with swapping channels, nor swapping channels only when the input is RAW DSD over I2S. PS Audio’s I2S interface is public and there are many units/companies who are compatible.


#25

oh OK Ted, thanks for clarifying.


#26

Strange thing is the Oppomod card has a PS Audio setting on one of the switches.


#27

I let Jaehong know about it. He’s involved getting a linear power supply made under deadline. After that, he’ll take a look at it. I’ll let you know if there’s an update.


#28

The oppomod card is known to have issues. The designer admitted that they have never tested the board with the PS Audio DSD.
Some people claim that it “works” but somehow don’t care that the left-right channels are reversed. So I am not sure if you can even trust their opinion.
My card has lots of static noise and does not play dsd at all.
Bad quality and not worth the hassle.


#29

All of the HDMI to I2S cards from that end of the world have the channels reversed, so presumably none have been tested with PS Audio eqpt. Sounds like you got a bad card. I did too initially and Jaehong sent me two to make sure one worked, which the first one I tried did. There is another to me much more important SQ problem, but it’s not clear whether it’s the cards or the DirectStream with I2S. There’s a discussion on another thread about that. Note that someone with a streamer also experienced the same problem discussed there, which suggests the source of the problem may not be the cards but the dac - I2S sound: What to expect?.

Update: I just go an email from Jaehong that says a new batch of cards with the channel reversal problem corrected will be available at the end of the month.


#30

From direct experiece, Oppomod cares, in the same way PS Audio cares about their Customers.

The card works, its fantastic and the fact he has sat down at his bench and redesigned the card to fix the channel swap issue, which wasn’t his fault, speaks volumes to me about the Company.

My Oppo 203 has been modded beyond all recognition with Jaehong’s inspired work and its night and day better in every way from the original 203 unit.


#31

I have no complaints about Jaehong’s customer service. He has been more than fair, sending me two boards and asking if I want a refund at a few points. I’m waiting to see how he wants to handle the corrected boards vs. the ones we have.

I just wish we could figure out what is causing the SQ results with the I2S cards. Given that someone with a streamer has experienced something similar, I have to wonder if it’s something about how the DS sees the I2S signal from some devices. Jaehong says his Korean customers aren’t having a problem, but I asked if they are using a DS and he didn’t, or hasn’t, replied. Btw, I tried an AQ Carbon HDMI in that position and it did not help. It does give a better picture than a store bought cable in the video out to TV position though.


#32

Whats the sound quality issues you speak of Gene?

Is it the floaty piano thing you metioned in the Snowmass thread?
Haven’t had the same thoughts here, and we share exactly the same source and Dac.

I WOULD say…
I2s does sound different, immediate impressions is it’s more exact, more laser focussed.
That quality (to me) subconsciously has always signalled “more digital sounding” and by that inferance a “bad thing”, but i2s out the Oppo into the Directstream is different from that.

Its just more accurate, with less artifacts, bloat and ‘added on stuff for flavour’.

My system is very revealing of differences and I have. SET tube amp, but one of the best which has none of the qualities sometimes asscociated with tube amps.
Its hyper accurate and just plays what its fed.

We are into a good thing with our DS Dacs and i2s output Oppos, pretty special digital sources my friend.
I have an equally costed vinyl front end and the digital gives up nothing to it.


#33

Not if you are passing the bit perfect tests - that shows the DS is getting what the source is sending. With the DS things like pitch of a track are set by the source for all inputs except USB (with USB the DAC can be the clock master.)

FWIW the Oppo’s have an idiosyncrasy that I haven’t seen in any other source. When they are cold their clocks are out of spec (more than 100ppm too slow) and it takes a few minutes for them to slowly drift into spec. That’s one reason the DMP replaces the Oppo clock system. I don’t know if the cards you are speaking about do anything to help the Oppo clock or if they use ASRC (Asynchronous Sample Rate Conversion, not likely if you pass the bit perfect test.)

Perhaps you should wait five or ten minutes after starting playing before you compare various outputs of the Oppo.


#34

The SQ problems reported by three of us - two re cards and one with a streamer - in I2S sound: What to expect? - occur all the time. I have to compare the external and internal cards, but it is essentially the same issue I raised about the external card earlier in this thread, e.g., post 139.


#35

For Oppo i2s users, its worth getting the clock upgraded for the reasons Ted touches on.
Immediately noticable improvement across the board over stock.


#36

Never the less pitch differences come from the source. The DS can only play the samples given, if they are given too slow the pitch is low, if they are given too fast the pitch is high. The DS limits the pitch change from a clock that’s too high or too low by doing a subtle sample rate conversion when the clock is technically out of range and the DS can’t reach it (I added that just for Oppo users (including myself.))


#37

I assume you’re referring to the OCXO clock. Does it go on the power supply board? Aside from Ric Schultz’s comments about its SQ, since it also requires Jaehong’s LPM, that’s an expensive gamble for a problem of unknown cause. In my case, since Ric changed my power supply, there’d be a question of compatibility and physical fit.


#38

Ted, You added that in Snowmass? So if the Oppo clock is the issue, it should be effectively taken care of now? I’m not hearing it and have been using the coax output this weekend to test SM, but will check again.

On the spdif run, I’m using the iFi SPDIF Purifier, inserted at the dac end. It claims to reclock and gavanically isolate the signal. Relative to the Boomsland cable alone, it has the sound effect of much greater clarity and moving the stage forward a bit, at least with with Snowmass. It’s described at https://ifi-audio.com/products/spdif-ipurifier/ (scroll down)


#39

No the kludge for very slow and very fast clocks has been in for, perhaps, all of the named releases (not in the early numbered releases.)


#40

Ric’s comments were about the i2s board not the OCXO clock board though?
And he never actually listened to it if I remember right.

The clock board overlays the Oppo’s main board, and is powered by Oppomods linear psu.
Yes, its an “all in” solution (and not cheap) but it really works well.

Compared to various “Signature Level” (and other marketing spiel) Oppo upgrade packages I see online, Oppomods are a bargain.


#41

Ric’s comments were about Oppomod’s clock, which he has since modified four times on his bench. Completing and offering a clock mod has taken a backseat to his “revolutionary” amp project, which is to be released soon and he hopes will allow him to get out of the mod business.