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[amp100 + DSP addon] DSP v13 dspproj TOSlink input

Julius Mehr

November 20, 2022 15:41

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Hi,

first: thank you so much for this incredible project, I absolutely love the setup. big fan!

However, I'm struggling with the TOSlink input to the Amp100 when trying to connect my old record player to the Hifiberry.

The setup is:

Cinch --> analog to S/PDIF 24 Bit / 192 kHz with Swissonic Converter AD 24/192 --> TOSlink Input on the Amp100 --> DSP with program version 13 on the DSP --> amp100 audio output.

 

The audio signal from the converter is received and some sound is played, however there is some noise on the signal as well. So:

1) is this setup even feasible or do I need a different analog to digital converter?

2) any chance I could have a look at the DSP v13 in sigma studio? On github, I only found the dspproj files up until v12, which does not work as well (It just plays a very loud hiss sound).

 

Thank you so much for any advice!

Julius

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8 comments

• 0
  
  Julius Mehr November 27, 2022 12:28

  Any comments from someone?

  I'd love to get this to work, somehow :)

• 1
  
  HiFiBerry team November 30, 2022 06:21

  In general this should work. 
  
  v12 and v13 DSP profiles are basically the same DSP program, only metadata for the SPDIF input have been changed. 
  
  My best guess is that the noise happens already on the analog input side. What pre-amplifier are you using? Did you correctly connect the ground pin of the pre-amplifier to the turntable ground?

• 0
  
  Julius Mehr December 06, 2022 20:38

  Thank you! It's promising that it could work in general :)

  Concerning v12 and v13: Interestingly there seems to be quite a drastic change from my experience, since I get this very loud hiss sound with v12 being installed as soon as the optical Input is being recognized, whereas with v13 I "only" recognize lighter hiss sound at certain frequencies.

  I'm using a cheap setup: My source is the Dual 210

  (manual [in German] https://asset.re-in.de/add/160267/c1/-/de/000311351ML03/AN_Dual-DT-210-USB-USB-Plattenspieler-Riemenantrieb-Schwarz.pdf)

  with the respective internal pre-amp (when switched on, of course).

  Additional Info: Previously I had the audio from the Dual 210 connected to another off-the-shelf stereo system, which worked fine.

  I see two general options:

  1. 1) trying to adjust the DSP program to handle the analog input from the Dual 210
  2. 2) including an additional pre-amp and switching off the internal pre-amp (?) --> if so, can you recommend any pre-amps that is supposed to work with the DSP v13?

  Thanks a lot!

  Edited by Julius Mehr December 06, 2022 20:39
• 0
  
  Julius Mehr December 06, 2022 20:52

  Or, in theory, I could maybe avoid the optical input all together and switch to a bluetooth connection:

  https://www.thomann.de/gb/pro_ject_phono_box_e_bt_5.htm?shp=eyJjb3VudHJ5IjoiZ2IiLCJjdXJyZW5jeSI6NCwibGFuZ3VhZ2UiOjJ9&reload=1

   

  which might work much easier, since the DSP programming is avoided.

  Right?

   

• 1
  
  HiFiBerry team December 07, 2022 08:36

  > Concerning v12 and v13: Interestingly there seems to be quite a drastic change from my experience, since I get this very loud hiss sound with v12 being installed as soon as the optical Input is being recognized, whereas with v13 I "only" recognize lighter hiss sound at certain frequencies.
  
  A lot of things can be parametrised which is basically the major difference. That doesn't change the DSP program, but different parameters can result in different behaviour.
  
  > Or, in theory, I could maybe avoid the optical input all together and switch to a bluetooth connection:
  Theoretically this might work with the BT source in HiFiBerryOS. 

• 0
  
  Julius Mehr December 17, 2022 18:41

  Hi,

  Theoretically this might work with the BT source in HiFiBerryOS. 

  I'm puzzled as to what is happening here..:

  attempting to connect via bluetooth:

  bluetoothctl scan on 

  doesn't find the Pro-Ject Phono box, but my Bluetooth headphones are found by both Hifiberry and the Phono box, I can now listen to my turntable on my headphones :) But this is not what I wanted..

   

  any strategies what I can try in order to get the connection to work?

• 0
  
  Julius Mehr December 18, 2022 16:11

  so, after some time I can give some more information:

  The mentioned Phono Box comes with

  Version 5.2 (Class II), A2DP 2.1 Support, aptX, aptX HD, aptX Adaptive

   

  the scanning utility finds the Phono Bo with neither 'ordinary' BT nor with BLE.

   

  My guess is that the installed bluez Version 5.62 in HifiberryOS is not capable of receiving the signal..? But i am not sure.

  Any ideas from someone?

  Cheers :) Julius

• 0
  
  Julius Mehr December 20, 2022 23:12

  Hi,

  Just fyi, before anyone is looking further into it:
  Adter quite some time investment I decided against the Bluetooth approach, since the implementation of Bluetooth communication seems to be too varying across different vendors.
  I am back at using toslink, to will post updates regarding the status in this thread.

  Julius