Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter

I use an AC transformer (3x9V), dipped in resin and shielded with a metal can. The transformer powers my 2xLinearPi and 1xSalas, which in turn power 3 UCconditioners, one UCconditioner (5V) powering the StationPiPro dirty side, one UCconditioner (5V) powering the StationPiPro clean side and one UCconditioner (3.3V) powering the FifoPi Q7 clean side.
 

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Hi Guys, I have a question for a DIY newbie and I would like to ask for an answer here.
Built a FifoPi Q7 II + ScPure 45/49 deck in GB23.
Its SQ level takes me to new heights. Before this I used Accusilicon AS338 solution.
The problem is that I am playing the beginning of each song or fast forwarding. There is a DADA sound in the deck. The sound is like a relay or something. But in my audio experience, the relay only works when the power is turned on and off.
Hope to get help. Is this normal? The mass production of DADA sound has greatly reduced the listening quality.
thx.
 

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I use an AC transformer (3x9V), dipped in resin and shielded with a metal can. The transformer powers my 2xLinearPi and 1xSalas, which in turn power 3 UCconditioners, one UCconditioner (5V) powering the StationPiPro dirty side, one UCconditioner (5V) powering the StationPiPro clean side and one UCconditioner (3.3V) powering the FifoPi Q7 clean side.
Hi @pkonstantinidis

Once again, you build looks really neat🙂

Do you also have a UcConditioner after your Salas power supply and what does that power in your stack?

Is the Salas PSU the Ultrabib 1.3 version and what current limit CCS have you set?🙂
Regards Mikkel
 
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@pkonstantinidis
Thanks🙂

I have a set of Salas ultrabib 1.3 regulators that i am not using. Just trying to see if I could incorporate one of them some how… The dirty side of the StationPi pro would also be my choice.
But not sure how much I will gain, rather than just have a single LinearPi+UcCond. PSU to power both the Rpi and q7 dirty side.
The only way is probably just to try☺️

The L-adapter look interesting to. I’ll have a look at that.
 
@miklau I have not suggested that the Salas L-adapter is better or worse than the LinearPi. The L-adapter is very flexible in terms of the voltage it can supply.

To avoid any misunderstanding, I am NOT using an L-adapter and a LinearPi and a UCconditioner in series. More specifically, I use the following combinations:

a) L-adapter --> UCconditioner 5V
b) LinearPi --> UCconditioner 5V
c) LinearPi --> UCconditioner 3.3V

https://www.diyaudio.com/community/threads/gb-for-salas-l-adapter-board.338109/
 
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Dear Ian,
I suggest that you start a forum in the DIYaudio Vendors Forum. For example the way Twisted Pear has done. You can have separate threads for your different products to make it easier to track people’s questions. This thread has been no help to me. I have posted a few simple questions here that just get buried in the general noise.

I think you can also moderate threads that go off topic and end up full of bickering.
Please consider this, Thank You
 
@SuLim
After inserting the SC Pure, I also heard the "relay-type sound" at every song change.
I have more or less your “tower” but simpler.
As a software I use GentooPlayer and the "relay-like sounds" disappeared when I changed the kernel to RT ones.
I can't give you a technical explanation but if you use the same software I invite you to try.
I hope this indication can be of help
 
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Today I finally managed to get the boards connected for a shakedown test to see if it all works.
I have not connected it to my stereo yet but was curius how the I2S signal looks like.

I installed piCorePlayer + LMS on 2 separate RPi4 and control it via the iPeng app on my iPad.
For LMS the setup looks like this: installed in an Inux3D printed chassis including space for a 2,5" SSD (1TB) which holds my music.
It is hidden near my circuit breaker panel where I also have my modem, router + switch.

980696ec-e061-42d3-aa93-7db293c420eb.jpg


piCorePlayer Setup:

86728fd6-d618-401e-803e-09752932b036.jpg


Tapping into the I2S signals:

ca0654bf-a3bc-4b6a-9269-da3b605fbfd2.jpg


My current (old) system consists of a BBB (BeagleBone Black) and did some measurements too when I built that system some years ago.
I have shown this system already in this topic, see post #11088

For this Ian Canada set I will build a similar enclosure with a divider to protect the FifoPi Q7 + TransportPiAES as much as possible from EMI/RFI.
I will use a GPIO flat cable to connect the Q7 to the RPi4 but when passing the divider it will go through a special ferrite core:

1f9cd301-ef14-4349-b20e-4119084ac004.jpg


And I also have a UCconditioner for 3.3 Volt.

From my BBB the SCK and LRCK looks nicest after the isolator to the DAC board:

Before the isolator; file is 44k1:
LRCK
9c8fe3ec-0634-4fce-a360-b178eb8b0f64.jpg

SCK
2fa7b33b-0f8b-43d9-8b59-c41e11a15a02.jpg


After:
LRCK
b525c41e-ac00-4bd9-9552-735d4b7203d3.jpg

SCK
accede30-14eb-4535-bcf0-d314c6668fdf.jpg


When going to hi-res 192k the SCK leaves much to be desired:

Before the isolator:
LRCK
1bc08344-4f98-4755-be59-df9c676adf72.jpg

SCK
5009710c-1dea-41e9-b2cd-549bc3c846df.jpg


After:
LRCK
b42a3710-926f-4be2-a485-ced62e416aa3.jpg

SCK
8e44a375-5cb6-4c80-a759-2b83ae58bc84.jpg


Now the IanCanada setup:

44k1: LRCK red/up and SCK yellow/down
641863c1-12c5-4aea-8377-a95ba153c274.jpg

7004f17c-3f63-4e08-8a99-da1bc9883331.jpg


192k: LRCK red/up and SCK yellow/down
75e0268e-a4e5-42ce-a45f-03531e7f06cf.jpg

94c5ef64-89b4-4f7b-9158-052de3ba76e7.jpg


What is also clear looking at the oscilloscope that the reclocking / very low jitter of the Ian Canada is very good ... the picture is rock solid and stable where with the old BBB the squares where jumping sideways which is the effect of jitter which is completely absent with this new set.

Once I am ready with the new cabinet and added a linear power supply as 5V main supply for the PurPi I can test the final result and hear how much improvement I get over the BBB setup.
 

@Gappone

Thank you for sharing. I will find time to familiarize myself with the operation of GentooPlayer. Currently I still use RoPieee with Daphile. Today I tried to unplug the 2-pin PH2.0 SYNC control signal line from the MonitorPi. The deck became quiet immediately. But in this way, one of its original advantages was lost. I feel regretful.