[xrobbo]

Hello,
did I get it right that with a device such as this AVB-DG module the connection through i2s is done without the need of an intermediate digital interface such as the DI-2014? That is, that one can go straight from the pc to the dac with a straight wire with nothing else in the middle?
If so, why this would not be possible with the inbuilt i2s module of the M7?

 

[Tini]

Hi Xrobbo,
 
Yes, you are right but that doesn't mean it is the perfect solution.
It is through Ethernet based on the Audio Video Bridging (AVB) standards. A standard switch will not work, so you will need a new switch in your network. Look at the AVB-DGK solution witch is also very affordable I think.
 
I would hope that someone with more technical skills than I would try this. If it's possible to build this into the M7 as a switchable input it would be a great add-on I think.
 
Regards,
Tini

 

[xrobbo]

Thanks,
on another forum, people have successfully used the following i2s card with a custom BB1704 based DAC. In that case any need of further devices is avoided: you go from pc to i2s card and then straight to the boards with the 1704 converters.
this is the card: http://jlsounds.com/i2soverusb.html
This should work also with the M7, I guess.

 

[Tini]

It's different, the JLsound is an USB to I2S card. More like the Amanero.
This uses Ethernet AVB (streaming) so you only need a network card witch is capable of the 802.1Qav protocol (and also a 802.1Qav switch) like the Intel I210-T1 on the computer. http://www.amazon.com/Intel-I210-T1-Network-Adapter-E0X95AA/dp/B00ESFF2JC.i
But I'm not a technician so the input from other forum members is more then welcome.
If it could work ( I think so) the question will be the SQ and if the jitter is low enough.
 
Tini

 

[DACLadder]

  Hello,
did I get it right that with a device such as this AVB-DG module the connection through i2s is done without the need of an intermediate digital interface such as the DI-2014? That is, that one can go straight from the pc to the dac with a straight wire with nothing else in the middle?
If so, why this would not be possible with the inbuilt i2s module of the M7?

Yes you have it correct.  Network audio is sent directly from storage to DAC via Ethernet.  A controller is also used somewhere in the chain, like an iPhone or iPad, as a player or traffic cop in this case.  Just as with an IP telephone call the controller just sets up the communication path and then does nothing until it needs to do so again.  The source and DAC talk directly transferring audio packets over Ethernet.  Google UPnP audio or DLNA for more information.
 
I'm currently auditioning a DAC with network interface.  It is extremely difficult to implement and get going reliably.  There are only a handful of controllers that support external "network renderers" (at the DAC).  JRemote by JRiver is supposed to be good but you need JRiver MC to use.  The only compatible controller for iPhone that I have found is PlugPlayer.  But it is not perfect.  Playback is not gapless for instance.  If the iPhone goes to sleep the music stops at the end of the current song.  And sometimes it recovers when you wake back up and sometimes it hangs.  So is very frustrating as software needs to catch up with the hardware it seems.  And my Ethernet hardware is very straight forward and simple with nothing else going on when playing music.   Sound quality very good though when it works!

 

[Tini]

Hi DACladder,
 
Did you try this as software: http://www.rogueamoeba.com/airfoil/windows/ ?
 
Tini

 

[DACLadder]

  Hi DACladder,
 
Did you try this as software: http://www.rogueamoeba.com/airfoil/windows/ ?
 
Tini

"Airfoil" looks like SW if you want to set up a PC running Windows as a network audio source.  And you would use companion iOS app Airfoil Satellite as the controller in this case.  Foobar 2000 also has a component allows you to create a Media Server (source) and Media Renderer (destination).  But these require Windows to be up and running.
 
My audio files are on the Synology NAS where I use "minimserver", running on the NAS, to the advertise to the network that audio is available.  There are several iOS apps that find minimserver as an audio source (as well as iTunes for example) but these apps will want to use iPhone or iPad as the network renderer.  They don't support external network renderers that I have found or if they do are brand specific.  If you come across any let me know.
 
As you can see in PlugPlayer's setup when devices advertise correctly they show up as Media Servers and Renderers.
 

 

[xrobbo]

I was wondering if there is a way to send to the M7 a 384khz or higher pcm signal.
It seems to me that already the amanero usb board can take up to 384khz (and one could anyway change that card), but there is somewhere a limitation to 192khz in the M7.
Where is this limitation implemented? In the DSP? In the dac boards? elsewhere?
the BB1704 can take up to 16x signals.
Supposing one wanted to listen to 708khz signals with a M7, would that be possible, under the obvious condition of replacing the USB card with a 16x capable card like this for example: http://www.diyinhk.com/shop/audio-kits/107-xmos-dsd-dxd-768khz-high-quality-usb-to-i2sdsd-pcb.html

 

[Articnoise]

  I was wondering if there is a way to send to the M7 a 384khz or higher pcm signal.
It seems to me that already the amanero usb board can take up to 384khz (and one could anyway change that card), but there is somewhere a limitation to 192khz in the M7.
Where is this limitation implemented? In the DSP? In the dac boards? elsewhere?
the BB1704 can take up to 16x signals.
Supposing one wanted to listen to 708khz signals with a M7, would that be possible, under the obvious condition of replacing the USB card with a 16x capable card like this for example: http://www.diyinhk.com/shop/audio-kits/107-xmos-dsd-dxd-768khz-high-quality-usb-to-i2sdsd-pcb.html

 

In NOS mod you can play 384 kHz with Amanero USB. Not with 8 x oversampling, which is the stock setting for the M7.

 

The PCM 1704 can play 768 kHz in NOS. I don’t know if it’s any other limitations that you will need to change more than the USB card.  

 

[xrobbo]

   

In NOS mod you can play 384 kHz with Amanero USB. Not with 8 x oversampling, which is the stock setting for the M7.

 

The PCM 1704 can play 768 kHz in NOS. I don’t know if it’s any other limitations that you will need to change more than the USB card.  

Ok. I thought that to go in NOS mode it would be enough to set on jumpers ATT1 and ATT0, and in this configuration my M7 cannot play higher than 192.
Even completely bypassing the DSP1 I cannot get the M7 playing at higher res than 192.
Is there something I get wrong?

 

[DACLadder]

 
Ok. I thought that to go in NOS mode it would be enough to set on jumpers ATT1 and ATT0, and in this configuration my M7 cannot play higher than 192.
Even completely bypassing the DSP1 I cannot get the M7 playing at higher res than 192.
Is there something I get wrong?

You need the latest DSP firmware from AGD to enjoy NOS up to 768Khz.  Kingwa states on the AGD main page soon upgrades will be offered for existing users.
 
http://www.audio-gd.com/En%20audio-gd.htm

 

[xrobbo]

  You need the latest DSP firmware from AGD to enjoy NOS up to 768Khz.  Kingwa states on the AGD main page soon upgrades will be offered for existing users.
 
http://www.audio-gd.com/En%20audio-gd.htm

From what I understand, this is a hardware rather software update.
But besides the 768khz, I should be able to play 384khz right now according to what Articnoise said, and I do not seem to be able to go beyond 192khz.
Any idea why?

 

[Articnoise]

 
From what I understand, this is a hardware rather software update.
But besides the 768khz, I should be able to play 384khz right now according to what Articnoise said, and I do not seem to be able to go beyond 192khz.
Any idea why?

 

Jumper IPS0 and IPS1 is for NOS. Jumper ATT1 and ATT0 is for stopband filtering.

 

I don’t have the M7 any longer, but then I had it I preferred to play native sample rates (I.e. no upsampling (to me it’s a difference)). This was both with 8x oversampling and then I used it with 2x oversampling *. For some records it can be little better if double the sample rate (44.1 ->88.2 Khz), but IME never more upsampling than double the native sample rate.

 

I don’t know if there’s some limitation also in the DSP that can limit how high sample rate one can play. You better ask Kingwa directly. Kingwa has made a NOS DSP that probable is better suited to handle NOS. The NOS DSP is btw different both in hardware and software. Not that I didn’t like the 2x oversampling on the normal DSP.

 

*Anecdote: The reason I never tried true NOS (1x oversampling) on M7 was because I and many others thought that bypassing Jumper4 IPS0 was 1x oversampling, but it’s not apparently. 

 

 

[xrobbo]

   

Jumper IPS0 and IPS1 is for NOS. Jumper ATT1 and ATT0 is for stopband filtering.

 

I don’t have the M7 any longer, but then I had it I preferred to play native sample rates (I.e. no upsampling (to me it’s a difference)). This was both with 8x oversampling and then I used it with 2x oversampling *. For some records it can be little better if double the sample rate (44.1 ->88.2 Khz), but IME never more upsampling than double the native sample rate.

 

I don’t know if there’s some limitation also in the DSP that can limit how high sample rate one can play. You better ask Kingwa directly. Kingwa has made a NOS DSP that probable is better suited to handle NOS. The NOS DSP is btw different both in hardware and software. Not that I didn’t like the 2x oversampling on the normal DSP.

 

*Anecdote: The reason I never tried true NOS (1x oversampling) on M7 was because I and many others thought that bypassing Jumper4 IPS0 was 1x oversampling, but it’s not apparently. 

 

Thanks, my mistake about the jumpers, you're right.
Anyway, did you ever successfully play 384khz on your M7 when you had it?

 

[Articnoise]

 
Thanks, my mistake about the jumpers, you're right.
Anyway, did you ever successfully play 384khz on your M7 when you had it?

 

No and I never tried because as I wrote don’t like the sound of upsampling. To polite, and for lack of better words not as true/real sounding IMO.