Loud ticking noise when music is paused/shift song

[miklau]

Hi Moode Audio.

Thanks for this great music player. It is very good 
I couldn't find any similar post so I decided to post a new thread. Please correct my if I am wrong

I have a very loud ticking/clicking sound two times a second when I pause the music player. There are also loud ticks when I skip songs and starts playing again. Present at Spotify connect mode/USB and even louder when using the UPnP renderer.

• Would it be possible to program a function that reads the "Play" or "Pause/Stop" state and then pull a GPIO pin high/low? That could then activate a mute function on my external PCM1794 DAC board when paused.
  

I have a RPI 3 running Moode 4.2 connected to an external asynchronous reclocker module using the TI SRC4192 and that is passed on to an external PCM1794a DAC. All from Twisted Pear Audio. The build in "Soft Mute" function of the SRC4192 does not help. 

Maybe someone have another good idea? 

COD DAC - Twisted Pear Audio   Metronome Reclocker - Twisted Pear Audio

[swizzle]

Sounds like it could be rf interference from the Pi, how are you connecting it to the external world?

[miklau]

Hi Swizzle.


Thanks for your reply.  I have connected the Pi with an ethernet cable. I have disabled BT and Wi-Fi. 
I also have an external Spdif to I2S board from Twisted pear Audio. The I2S signal from the Pi and Spdif is passed through a Omron relay selector switch. If I experience the ticking noise and switch between the two input and back to the Pi, the noise stops. Bypassing the switch doesn't solve the problem.

If I pause the music at the last second of a song the ticking sound is not present. If I pause the song at any other point the ticking noise starts. 

Very strange and very annoying 

[Tim Curtis]

What type of cable assy are using for the I2S connection between the Pi and the TP board?

-Tim

[miklau]

Hi Tim

Thanks for taking your time to look at this

Iam using some single wires from a "Low Voltage Control cable" without shielding using this standard: Cable I would expect the wire thickness to be 0,25 mm2 or maybe 0,34 mm2.

I have arranged my boards to minimize the length of the I2S wires. Please look a the pictures. 

I have also tried to use some very cheap 2.54 Dupont ribbon cable with the same result...

Is there any difference between to "Pause" or "Stop" a song? 
       

[Tim Curtis]

Nice DIY rig :-)

I think both MPD stop and pause close the audio output. MPD retains the songs time position when paused. When stopped MPD uses time position 0 (beginning) when play resumes.

From what I've read, best I2S interconnect should be made from U.FL micro coax cables to prevent signal degradation and EMI. Iancanada's Twitter feed has pics and info regarding U.FL cable assy and an adapter for Raspberry Pi that fits on top of the 40 pin header.
https://twitter.com/iancanadatt?lang=en
http://www.diyaudio.com/forums/group-buy...t-buy.html

I've also been told that the thin copper wires from CAT5 or higher Ethernet cable can be used for I2S interconnect. The person that mentioned this said that this wire is high quality and engineered for high frequency signal transmission. He said each wire should be twisted with a GND wire. I've never tried it so I can't say one way or the other how it performs.

-Tim

[miklau]

Thanks again Tim

I have came across the products from Ian before and they are very nice. I have thought of buying his Isolator Pi to improve and SQ and because of the u.fl. connectors as well.

I am only having this click noise when playing music from the Pi -> I2S switch -> reclocker -> DAC. When I use SPDIF to I2S converter board from Twisted Pear Audio there is no clicks at all; SPDIF/I2S -> I2S Switch -> Reclocker -> DAC. All is with the same wires. 
It is like there is some kind of signal "hanging" from the Pi and that is maybe interpret wrong by the reclocker board. I am not sure about this  ! Thats why I thought of "programming" something that could pull the mute pin high on the DAC when the music is not played. I do unfortunately not have those programming skills   

There are no clicks if I pause a song within the last 2-4 sec. of the song...

[aBrianH]

Thanks again Tim

I have came across the products from Ian before and they are very nice. I have thought of buying his Isolator Pi to improve and SQ and because of the u.fl. connectors as well.

I am only having this click noise when playing music from the Pi -> I2S switch -> reclocker -> DAC. When I use SPDIF to I2S converter board from Twisted Pear Audio there is no clicks at all; SPDIF/I2S -> I2S Switch -> Reclocker -> DAC. All is with the same wires. 
It is like there is some kind of signal "hanging" from the Pi and that is maybe interpret wrong by the reclocker board. I am not sure about this  ! Thats why I thought of "programming" something that could pull the mute pin high on the DAC when the music is not played. I do unfortunately not have those programming skills   

There are no clicks if I pause a song within the last 2-4 sec. of the song...

Not sure if it is the same sound but the last couple of versions have 'clicked' in the time between each track. Possibly not the same but I got a quieter between tracks by setting Gapless mp3 playback to No. Far less obvious sounds, more hush

[miklau]

Thanks for advice aBrianH. I did try it and there was unfortunately no change to the ticking...

I do belive this is hardware related to the ASRC module using the SRC4192 from Twisted pear audio. I found this thread on the TI community stating that the "output data is not always zero even if the input stream is zero" and that it is "normal behavior". The only solution is to bypass the SRC4192 or use the mute function...
https://e2e.ti.com/support/audio/f/6/t/6...utput-Port

I am waiting for a IsolatorPi and maybe this could help somehow even through I am not sure if this help after I found the TI thread...

So making a small script with a pull function for a mute pin could be a small project for me  So if anyone have a good advice on how to build a script please let me know Any help is more than welcome

[miklau]

@Tim Curtis 
Hi again Tim

I have looked through different forums and found this Switching Amps. thread. Could this be a future implement in Moode Audio ? I am not quite sure how to implement this on my own but I will ask about that in the other thread

Regards Mikkel