Hi,
I have some isssues with my Hifiberry Digi and a Denon DA 500 DAC. The DA-500 can lock to the signal and plays via Toslink and Koax APDIF equally. The strange thing is that the DA-500 is not recognizing the CLock somehow and therefore the Frequenz indicators are not lighting up (32,44.1,48 khz).
I tried this with Volumio & Raspbian and I have a Rasberry PI 2.
I checked this with Airplay and Direkt Play or mp3's and Waf files with all 3 different Sample rates. The Frequencies are never indicated (a Denon x4000 proves though that the actual signal is according to the source files).
A usb dac, atv3, and an OLD Denon cd Player with spdif do get recognized properly.
So here my questions:
-Is the i2s clock of the PI so inacurate and the Wolfson 8804 is following this pace via PPL that the DA-500 cant recognize it completly?
-Is actually the Wolfson 8804 buffering and reclocking the signal (it has a Quartz)? And is maybe slightly to fast or slow?
-Are there specific bits set/unset within the SPDIF/PCM stream. Copy bit etc. which the DAC maybe expects?
-Are there Known Issues with the DA-500 or a yamaha YM3623 spdif receiver?
its really a strange behavior which leaves my the flavor that my setup is having issues and might not sound as good as possible.
with kind regards,
--thomas
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Thomas Hi Daniel,
I experienced a second "strange behaviour" on my digi+. (I have the Digi with the little transformer.) And when I connect the DIGI to a Teac UD 501 and turn on another device next to my DAC and PI the signal via Coax cable get lost and the UD501 is resyncing ... (the drop is not longer than a second). I tested with the TOSLINK/USB and the issue did not appear.
If I connect an old CD player with Coax digital link this behaviour does not happen as well.
So my question is if the little transformer is very voulerenable towards external influences like magnetic fields or has in comparison to a device with direkt connection "less" power so that external influences have it "easier" to influence...
The Pi was even 2 meter away from the other equipment...but is in non shilded case.
with kind regards,
--thomas
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HiFiBerry team Hi Thomas,
we heard about this only once before. In general the transformer is shielded. However this works only, if your Raspberry Pi itself is connected to ground. If you use a standard USB charger, this might not be the case. A shielded cases is not needed, but grounding the Raspberry Pi might help.
Best regards
Daniel -
Thomas Hi Daniel,
thanks for the hint. You have a good guess how to ground the pi in a safe way? Coz I never saw such small power supply which is using the safty ground (schuco). They usully follow the principle of Safty insulation. And I dont wanna greate eath loops ...
I guess in a first stepp i will try different power adapter .... and keep testing.
BTW. They did not update the PI'S software yet with the DIGI fix. Would it be possible to put the kernel image onto a ftp or similar? I am to curious to test the fix and have not really the time to dive into a kernel build.
thanks for your feedback!!! BTW I live in Berlin and just learned u have an office here as well. SO for testing purpose I could also carry my DAC into ur Offices if you have technical expertiese there. (Maybe its more a sales office?).
many greetings,
--thomas -
Thomas Hi Daniel,
here some feedback. I tried some different Power Supplies but with the same effect. When I shielded the pi with AL Foil and grounded it via the Ground from the SPDIF coax cable which is connected with my grounded DAC. After Doing this the Problem was gone. Without shield its even sensitive to any power related event... like turning on/off the desk lamp.
Here my thoughts... wouldn't it be an improvement in general to connect the Ground/Shield of this little Transformer with the Ground of the connected device instead with the local Ground which is actually in 99% of the cases isolated by the power supply and therefore not functioning.
Or it could be even made configurable via a jumper to choose the ground either the local or external. I don't know if this would violate audio design pattern but it would in this case probably help to deal with grounding shielding issues.
Since the Digi+ with Transformer is already the "esoteric high end" version, this could be a nice improvement.
And I think its good to avoid the real grounding of the Pi, which avoid ground loops or other potential issues if the Pi gets connected with different external devices.
with kind regards,
--thomas -
HiFiBerry team Hi Thomas,
Berlin is only a sales/distribution office, we don't have a lab there. We might think about changing the shielding of the transformer in future versions.
Best regards
Daniel -
Thomas Hi Daniel,
This is great news! If you want me to do some tests on a changed prototype please let me know.
In the meantime I am wondering if I could replace my digi+ against the model without a transformer. And you could maybe send a lose transformer with it (which I then can solder in a way with a changed ground)? I ordered my Digi+ on February 9th and it arrived like 3 weeks later.
That way you could also see if this designchange would fully work. Is the Transformer the only difference between the two versions of the Digi+? Or are there also some SMD's or other parts which would be missing?
with kind regards,
--thomas -
HiFiBerry team While we think about a changed design, it will take some time until it is really available. I wouldn't expect it in the next 2-3 months.I can't commit any date for this yet, as we have a lot of other projects that we're working on.
If you like, we can change the transformer version to a standard version.
Best regards
Daniel -
Samuel Darby @Daniel - I compiled a Raspberry Pi Kernel that contained your change (3.18.9-v7+) for the SPDIF status bits and am pleased to see that the Lindy DAC is now displaying the correct frequency. Thanks for this fix so soon.
The build took about 2 hours using make -j4 on a raspberry pi 2. As referenced in other posts on this forum I had to run this to enable the device tree in the newly built kernel file:mkknlimg zImage kernel7.img
I did revert to 3.18.7-v7+ to confirm the original behaviour.
I also realised (after I'd waited for the kernel to build) that there are nightly builds of the rapsberry pi kernel. However, despite the nightlies installing 3.18.9-v7+, your change did not seem to be included. -
HiFiBerry team Dear Samuel,
thanks for the feedback. I don't knowwhere the nightly build come from. The change has been merged into the official raspberrypi/linux repository already. But maybe the nightly build come from another source.
Best regards
Daniel -
Thomas HI Daniel,
after a long time I were not working with linux... I managed to compile the kernel with the latest source (onto the Pi) ... On the RPI2 the kernel build is really fast...
And the good news is that also my issue with the DA-500 is fixed! The frequencies get displayed correctly. Very good job Daniel!!! I am very pleased now and it gives a much better feeling when the things work as expected.
with kind regards,
--thomas -
Thomas Hi Daniel,
because its now all quiet working (except the insulation issue with the transformer). To keep the buerocracy simple ... Could I keep the current version until you have released the updated model (with the ground assigned to the client device) and thereafter we exchange the Digi+ (maybe here in Berlin) since its just a few blocks away.
I am fighting here with some soft grounding issues and think it's very good to have the transformer version.
many regards,
--thomas -
HiFiBerry team Hi Thomas,
we can do this. However I can't say when the new version will be available.
Best regards
Daniel -
Thomas Hi Daniel,
with me its fully fine also if it takes a bit longer. Another "idea" for the "premium" version of the board would be a bit better connectors, which provide more hold. The current spdif connector bends a little especially if customer use high quallity thick cables. so a connector with a little srew into the board would be fantastic.
I have onother question regarding the current driver. If I would theoretically stack 2 Hifiberry's above eachother... e.g a DIGI+ and a DAC+ (via the second solder points) would the drivers manage the specific board adressing and I2S data trasfer. The 2 cards then could be listed as multiple soundcards.
with kind regards,
--thomas -
HiFiBerry team Hi Thomas,
we don't plan a "premium" version. Two sound I2S sound cards are not possible as I2S is a point-to-point connection and not a bus system.
Best regards
Daniel -
Thomas Good evening Daniel,
I just recognized that the indication of the sample frequency's is not working again. Is it possible that it got taken out of the kernel for some reason?
I am currently using the following kernel version: 3.18.7-v7+ #755 (I think it was updated 3 days ago)...
with kind regards,
--thomas -
Thomas Pls forget my last post. I think for some reason my update mechanism is acting strange.... and the kernel version actually loaded is too old.
kr,
--thomas -
Thomas Hi Daniel,
I wanted to ask you if there is already a version of the Digi available were the little transformer is not shielded or shielded by the connected device?
with kind regards,
--thomas -
HiFiBerry team Hi Thomas,
the latest version uses the GND from the receiving device as shield potential.
Best regards
Daniel -
Thomas Hi Daniel,
these are lovely news, since I am living in Berlin... can I just go to your Berlin location and exchange my DIGI there? I guess you have those devices there on stock?
with kind regards,
--thomas -
HiFiBerry team Hi Thomas,
our Berlin office is not a shop were you can walk in. You can send it to us by mail or you can visit us in October to the Berlin MakerFaire.
Best regards
Daniel
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