I've just finished my first version of MIRO's AD1862 DAC. I used v1.3 with uf.l connectors.
Currently with the onboard I/V using OPA627 opamps on adapters
Connected to raspberry Pi with FifoPi Ma and using Volumio
Currently powering it using Tektronix bench power supplies.
I'm getting music through the DAC but it's almost overwhelmed by hum and noise. I can just barely hear the music.
All suggestions for improvement and correction will be most appreciated. I have very little experience with building/troubleshooting DACs
Currently with the onboard I/V using OPA627 opamps on adapters
Connected to raspberry Pi with FifoPi Ma and using Volumio
Currently powering it using Tektronix bench power supplies.
I'm getting music through the DAC but it's almost overwhelmed by hum and noise. I can just barely hear the music.
All suggestions for improvement and correction will be most appreciated. I have very little experience with building/troubleshooting DACs
I've assumed that ground is connected via the uf.l connectors. Is that correct? I'll add a second connection. I suppose this ground should be between the FifoPiMa and the DAC since the RPi is isolated from the FifoPiMa - correct?
Added a ground connection between DAC and FifoPi but no effect. Am I connecting incorrect points?
Could the hum and noise be cause by use of a bench power supply? I have a PSU2 that I'll put into use.
Added a ground connection between DAC and FifoPi but no effect. Am I connecting incorrect points?
Could the hum and noise be cause by use of a bench power supply? I have a PSU2 that I'll put into use.
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Does it work for you? Configuration for the newest I2SoverUSB: https://www.diyaudio.com/community/...s-input-nos-r-2r.354078/page-367#post-7448300
Correct, uf-l wires are all grounded, check the central pins with a DVM for continuity.
Have you a dip 8 single channel op amps else than these ones to check ?
How do you stream ?
Have you a dip 8 single channel op amps else than these ones to check ?
How do you stream ?
It looks like volumio should be configured in settings. I am not sure how because I have zero experience with this kind of shields and volumio, but in settings try to find a section for I2S output or DAC output and try change settings. This DAC accepts I2S format with BCK = 64 fs, Left-Justified (in other words the most used standard I2S format). It can be represented as 2x32 Bits I2S left justified, or something like that. 64fs for bck means, that one LRCK cycle has 64 BCK counts. There are another formats like 48fs where is 48 bck counts in one LRCK cycle. You need 64fs. When you open PCM2706 datasheed on the page 19, in figure 22 you can find the visual representation of the data format (LRCK, BCK, Data OUT). Such a format should be set in the volume, or a DAC that supports such a format should be selected 😊
You can test the functionality easily with the cheapest USB-I2S convertors from aliexpress, this is what I highly suggest for new builders 🙂
Thanks. I verified that the uf.l cables are providing grounding.
I think I have a couple AD797 and a couple NE5534. I'll try one in each channel.
I'm streaming using Volumio on a raspberry pi model 4 - currently into a Iancanada FifoPi Ma which outputs the I2S connected via uf.l to the AD1862 DAC
Thanks for this information. I'll check into Volumio but I don't recall it having that much flexibility. It basically relies on drivers that are DAC-specific. Currently I'm using the HifiBerry DAC Plus, which is recommended by Iancanada. I'll see if I can find the specs for that DAC as it will give some insight on the specs.
I do have an Amanero Combo that I can use as input and will give that a try. Good suggestion. I'll also look into the output specs of the FifoPi Ma to see if it aligns.
@hirscwi try to disconnect uf.l and check if you still have hum. Hum can also come through connection to your power or pre-amp - through the power ground loop. Make sure that your ground on the DAC is connected to the power ground as described in this thread few times. Try disconnecting one of the channels and see if it solves the problem. Also, if you have a scope, try to check the output without connecting to anything as well as to check if there is any AC on the +/-5V and +/-12V. Hum can also be an indication of high frequency instability - did you install 100R on the output and 47pF caps - are your opamps warm?
Try also in Volumio in the DAC driver list, a dac based on AK4490, etc or AK4396. If not working play with the others Volumio choice.
But yes find first if the hum is electraly or not first.
But yes find first if the hum is electraly or not first.
Thanks for the suggestions. I'll follow up on them in the morning. I did install C31 and C36 - C0G SMD on rear. I also installed R10 and R11 - 100 ohm.
With the stacked board, you are actually ready for this power option:
"provide external power supply to H3.17 and H3.19" is executed when you install J14 and short SJ3.
This is the beauty of this board.
And then you do this:
Please do not install this pin. This pin on the DAC board is the ground to USB section.
On the latest JLS board, that pin (#10) is 'isolated ground'.
If you are using separate psu to power the USB and clock, and you want isolation, please do not connect this pin. Snip it away.
hirscwi is not using a DAC hat, hence he does not need to configure it this way.
Volumio will auto detect the i2s interface.
For the FIFOPI, it may be required to turn on i2s DAC... which i believe the setting should have been done by hirscwi since it is already playing music.
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I tried this and it made no improvement.
I installed the Amanero and it works just fine. Therefore I conclude there's a problem with the RPi/FifoPiMa setup. I believe that I should take my question to another thread unless someone here has experience with the FifoPi Ma setup.
At least it's good to know that the DAC works as it should.
Thanks to all for assistance.
As mentioned, the Amanero works - so the problem is not with the DAC. Thank you.
Could there be a mis-match between the way the FifoPi Ma outputs I2S data and the conversion provided on the MIRO AD1862 DAC?
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