Multichannel audio on a Pi will get a whole lot easier and cheaper!

[MCH]

Hello MCH i saw this HDMI to I2S Board as i ordered the other one, because on the Board is written 6 CH HDMI to I2S and not 8CH that makes me Skeptical not sure what does it mean.

But 4 I2S Lines SD0-SD3 you can see there also, not sure about this. May be a mistake by them.

Robert

Good catch. I bet it does 8, but you are right, very confusing.

 

[Frunse]

One little Question.
I have one Motu UL mk5 it has 10 Analogue OUts with Volume control!
i need 16 Outs at all.

I have 3 Option:
1. Motu A16 around 1600€ (Not sure if its run on Linux) Specs: 123dB Dynamic, 110db THD+N (Sabre ES9016, ES9018?)
2. Motu AO24 around 1250€ (Not sure if its run on Linux) Specs: 123dB Dynamic, 110db THD+N (Sabre ES9016, ES9018?)
3. second Motu UL mk5 712€ (Connecting with ADAT 4 CHannels at 96kHz + 2 Chanels SPDIF at 96kHz) works sure on Linux, same Soundperformance like on first MOTU UL
Volume control on 2 Devices could be only used independent but visualy you could sync the Value on screen) Specs: 125dB Dynamic, 114db THD+N (Sabre 9028PRO DAC)


ON 48 kHz you has 20 Channells at all
This extra 6 Chanels i would use for Surround Back left and right and Center so for Stereo only first Motu needet and for surround i could use both.

I go for 3.

What you say?

Anyway, cheepest and by sure, will work option, so ordered it

Robert

 

[renne]

One little Question.
I have one Motu UL mk5 it has 10 Analogue OUts with Volume control!
i need 16 Outs at all.

I have 3 Option:
1. Motu A16 around 1600€ (Not sure if its run on Linux)
2. Motu AO24 around 1250€ (Not sure if its run on Linux)
3. second Motu UL mk5 712€ (Connecting with ADAT 4 CHannels at 96kHz + 2 Chanels SPDIF at 96kHz) works sure on Linux, same Soundperformance like on first MOTU UL
Volume control on 2 Devices could be only used independent but visualy you could sync the Value on screen)

ON 48 kHz you has 20 Channells at all
This extra 6 Chanels i would use for Surround Back left and right and Center so for Stereo only first Motu needet and for surround i could use both.

I go for 3.

What you say?

Anyway, cheepest and by sure, will work option, so ordered it

Robert

Are you going to synchronize the clocks of the two Motu UL mk5 via SPDIF?

 

[sarieri]

One little Question.
I have one Motu UL mk5 it has 10 Analogue OUts with Volume control!
i need 16 Outs at all.

I have 3 Option:
1. Motu A16 around 1600€ (Not sure if its run on Linux)
2. Motu AO24 around 1250€ (Not sure if its run on Linux)
3. second Motu UL mk5 712€ (Connecting with ADAT 4 CHannels at 96kHz + 2 Chanels SPDIF at 96kHz) works sure on Linux, same Soundperformance like on first MOTU UL
Volume control on 2 Devices could be only used independent but visualy you could sync the Value on screen)

ON 48 kHz you has 20 Channells at all
This extra 6 Chanels i would use for Surround Back left and right and Center so for Stereo only first Motu needet and for surround i could use both.

I go for 3.

What you say?

Anyway, cheepest and by sure, will work option, so ordered it

Robert

Motu avb on linux is a bad idea. There are lots of reports that they don’t work well.

 

[somebodyelse]

3. second Motu UL mk5 712€ (Connecting with ADAT 4 CHannels at 96kHz + 2 Chanels SPDIF at 96kHz) works sure on Linux, same Soundperformance like on first MOTU UL
Volume control on 2 Devices could be only used independent but visualy you could sync the Value on screen)

You should be able to send the same volume settings to both Ultralites via their websocket API:
https://www.audiosciencereview.com/...tor-section-remote-project.52465/post-1894892

 

[Frunse]

Are you going to synchronize the clocks of the two Motu UL mk5 via SPDIF?

Thats outomatikly because they connected this way ADAT (4 Channels) and Spdif (2 Chanels) the second Motu is Synct to Spdif or Toslink, no USB used but you need to setup it right sure.

Robert

 

[Frunse]

Motu avb on linux is a bad idea. There are lots of reports that they don’t work well.

No AVB Switch Used! They connected on Hardware side with Spdif and Toslink like an external Dac.
No AVB Plugin used or Library on Linux.
I will Report you how it goes by sure

Camilla DSP Outs on Motu 1 Device by default!
Outputs:
0-9: analog 1-10
10-11: headphone 1-2
12-13: SPDIF 1-2 to Motu 2 SPDIF in (96kHZ)
14-15: TOSLINK/ADAT 1-2 to Motu 2 ADAT 1-2 IN (96kHZ)
16-17: ADAT 3-4 to Motu 2 ADAT 3-4 IN (96kHZ)
18-19: ADAT 5-6 (48kHZ only)
20-21: ADAT 7-8 (48kHZ only)

All without AVB

Motu UL mk5 dont has Networkinterface! AVB only for Network right?

Or you mean specialy the other Devices? They have USB 2 Compilant Conection also!
But cant find information how it works with Linux seems no one used it for now.

Robert

 

[Frunse]

You should be able to send the same volume settings to both Ultralites via their websocket API:
https://www.audiosciencereview.com/...tor-section-remote-project.52465/post-1894892

Sounds interesting need to Check this if the Device is arrived.
But the Second Device isn't connected with USB, may be i could do it without using it as an sound Device (Alsa would indetified it and the list with Devices would be realy confusing), not sure if its works on the same PI with 2 Motus on USB. need to test this all.
I will Tell you guys, what will go, how well.

If its working with Both USB Devices as one Device on CamillaDSP with 20 Analogue Outs, synced both together with SPDIF or Toslink without Delay Problems, that would be raely an Powerfull System. I would Love it.

https://medium.com/home-wireless/how-to-run-camilladsp-with-multiple-dacs-9672a4639cf3
Without Sync it wont work like on that Link and this are only 4 Channels Dacs not 22 Channels!

Thank You.

Robert

 

[sarieri]

No AVB Switch Used! They connected on Hardware side with Spdif and Toslink like an external Dac.
No AVB Plugin used or Library on Linux.
I will Report you how it goes by sure

Camilla DSP Outs on Motu 1 Device by default!
Outputs:
0-9: analog 1-10
10-11: headphone 1-2
12-13: SPDIF 1-2 to Motu 2 SPDIF in (96kHZ)
14-15: TOSLINK/ADAT 1-2 to Motu 2 ADAT 1-2 IN (96kHZ)
16-17: ADAT 3-4 to Motu 2 ADAT 3-4 IN (96kHZ)
18-19: ADAT 5-6 (48kHZ only)
20-21: ADAT 7-8 (48kHZ only)

All without AVB

Motu UL mk5 dont has Networkinterface! AVB only for Network right?

Or you mean specialy the other Devices? They have USB 2 Compilant Conection also!
But cant find information how it works with Linux seems no one used it for now.

Robert

I meant to say the AVB Series. There are lots of people having trouble with motu 828ES and motu ultralite AVB. Camilladsp either can't read all channels of their device or it cannot have a logical mapping.

Edit: I was reffering to stuff like motu 16a/24a. Ultralite mk5 is not in the AVB series.

 

[Frunse]

I meant to say the AVB Series. There are lots of people having trouble with motu 828ES and motu ultralite AVB. Camilladsp either can't read all channels of their device or it cannot have a logical mapping

Still would be interesting how they Perform as an Standalone USB 2 Class Device with CamillaDSP on Linux.
But the Specs are also better on UL mk5, let see how its works with 2 of them

16 Channel will do my Setup, if its works with More Channels even better, but don't think so. To many latency shift Problems between 2 USB Devices i gues.
We will see (I will Measure).

Robert

 

[sarieri]

Still would be interesting how they Perform as an Standalone USB 2 Class Device with CamillaDSP on Linux.
But the Specs are also better on UL mk5, let see how its works with 2 of them

16 Channel will do my Setup, if its works with More Channels even better, but don't think so. To many latency shift Problems between 2 USB Devices i gues.
We will see (I will Measure).

Robert

I never tried but you can create an aggregate alsa device and use that with cdsp. Henrik mentioned about it on diyaudio and it should work. But I wonder how are you going to get a source with this many digital output?

 

[mdsimon2]

I meant to say the AVB Series. There are lots of people having trouble with motu 828ES and motu ultralite AVB. Camilladsp either can't read all channels of their device or it cannot have a logical mapping.

Edit: I was reffering to stuff like motu 16a/24a. Ultralite mk5 is not in the AVB series.

Biggest issue I’ve seen with MOTU AVB interfaces on Linux is bit crush type distortion and swapping of channels. I certainly wouldn’t use one on Linux.

3. second Motu UL mk5 712€ (Connecting with ADAT 4 CHannels at 96kHz + 2 Chanels SPDIF at 96kHz) works sure on Linux, same Soundperformance like on first MOTU UL
Volume control on 2 Devices could be only used independent but visualy you could sync the Value on screen) Specs: 125dB Dynamic, 114db THD+N (Sabre 9028PRO DAC)

If you are already using CamillaDSP, why not just use that for volume contro?. I use CamillaDSP to control all digital and analog outputs of my UL Mk5 and it works great. There would be no need to worry about synchronizing volume across two DACs this way.

Michael

 

[Frunse]

I never tried but you can create an aggregate alsa device and use that with cdsp. Henrik mentioned about it on diyaudio and it should work. But I wonder how are you going to get a source with this many digital output?

HDMI 7.1 In to Full aktiv Setup with Camilla DSP
I Use the Mentioned HDMI to I2S Board in this Threat.

Robert

 

[Frunse]

Biggest issue I’ve seen with MOTU AVB interfaces on Linux is bit crush type distortion and swapping of channels. I certainly wouldn’t use one on Linux.



If you are already using CamillaDSP, why not just use that for volume contro?. I use CamillaDSP to control all digital and analog outputs of my UL Mk5 and it works great. There would be no need to worry about synchronizing volume across two DACs this way.

Michael

At all i dont like Volume Control in Digital Domain thats degrade the Reselution even in 32Bit before the Dacs and because of the Open Analogue Outs after the Dacs i have Noise from Tweeter, i can heare it, i am sitting only 2,5m from Speaker away, have an smal room!
I f i use an Analogue Volumecontrol between the Dacs and Amps i reduce also the Noise, by Resistor Devider, right? and the Dacs getting the Maximum Digital Signal In.
I know 64Bit Volumecontrol has a lot of spare Reselution but the noise from tweeter are realy Nerving me.

Its like on an Full Amp if you set the Volume up the Noise going up too. So better to have an Analogue Relay Attenuator in Between.

For now i use Volumecontroll on Motu to get the apropriate Volume in my room at -20dB Out as Max Level and Use CamillaDSP for finetuning between -15 and 0 dB

Before i had an Najda DSP Board it had an CS 8 Channel Analogue Volumecontrol and i didn't got any Noise from Tweeter with the same Amps and Speaker, that why
I will Spend so many Money to gat an descent Analogue Volumecontrol for all Channels.

Robert

 

[phofman]

@Frunse: I do not know your whole plan. But have you checked your DACs really have analog volume control?

I know 64Bit Volumecontrol has a lot of spare Reselution

In the end it has the same spare room as 24bit volume control because first float64 -> int32 before the driver and then int32 -> int22 max by physical resolution of the DA conversion.

 

[Frunse]

@Frunse: I do not know your whole plan. But have you checked your DACs really have analog volume control?


In the end it has the same spare room as 24bit volume control because first float64 -> int32 before the driver and then int32 -> int22 max by physical resolution of the DA conversion.

??? I mean Volumecontrol on CamillaDSP is set while data has transfered to 64Bit right and than Volume calculatetd to this 64Bit Data right? and than transfered back to 24Bit before Dacs or not?
Also on Fubar windows you has an 64Bit Volumecontrol before convertet to 32 or 24Bit to the Dacs or not?

ON Motu Volumecontrol is in DAC SABRE 9028Pro or elswere on Digital Domain (32Bit) so no Analogue Volume.
My old Najda DSP has an Analogue Volumecontrol Chip from CS for 8 Channel after Dacs by sure.
And that was Perfect that way.
May be i need to build up such an 16 Channel Version but i gues Relais with the right Resistors are better in Performance and no conversion Sym. to Asym. and back Asym. to Sym.

But Probably if you are use 2 Channels per XLR Signal for full Symetric Volumecontrol with 4x 8 Channel CS Chip it would work and still cheeper than relais.
DigiKey Price is 31€ if you buy 10 or 33,54 € for one so not the Cheepest Chip.
Or PGA4311U 4 Channel Chip 17€ per piece (2 XLR Channels) you need 8 of them for 16 Channel
Need to rethink all may be Chips are much more Cheeper and still good enough.
On Arduino (in General) you can have 16 Devices on on one I2C Bus right?

Twisted Pair one Relaisboard 65$ for one XLR Channel!!!

If Volume will Calculated to an 64Bit Data it has much more Steps for Calculation and the lowered Signal are much more Pricise against 24Bit or 32Bit or I am understand something absolutly Wrong.

Look at Attachment.

Robert

 

[mdsimon2]

@Frunse From the statement "second Motu UL mk5 712€ (Connecting with ADAT 4 CHannels at 96kHz + 2 Chanels SPDIF at 96kHz) works sure on Linux, same Sound performance like on first MOTU UL Volume control on 2 Devices could be only used independent but visually you could sync the Value on screen)" and subsequent discussion I assumed you were considering using the MOTU volume control on two separate MOTU UL Mk5s. As you note, the volume control on the MOTU is certainly digital. I have not observed any measurable difference between the MOTU volume control and CamillaDSP as the limit is still the analog noise performance of the MOTU UL Mk5 itself.

That being said, an analog volume control can beat the performance of digital volume control at lower levels, but that comes with a lot of complexity, especially with 16 channels.

Michael

 

[phofman]

64Bit Data it has much more Steps for Calculation and the lowered Signal are much more Pricise against 24Bit or 32Bit or I am understand something absolutly Wrong.

I am afraid the latter is the case - if you arduously calculate an operation at gazilion precision and then throw away most of the precision (explicit truncation to 32 bits samples, implicit truncation to 22bit noise/signal resolution), the resultant number will be identical to making the calculation directly at the lowest precision of the chain (+/- LSB for rounding errors). Explicit 64bit volume control is a nonsense audiophiles want to see, that's why the softwares do it. CDSP does it because it runs the whole complicated DSP at float64 (where it makes perfect sense because DSP does thousands of operations on the same sample with tiny coefficients where rounding errors add up quickly - unlike volume operation which is a single division on each sample).

 

[Frunse]

I am afraid the latter is the case - if you arduously calculate an operation at gazilion precision and then throw away most of the precision (explicit truncation to 32 bits samples, implicit truncation to 22bit noise/signal resolution), the resultant number will be identical to making the calculation directly at the lowest precision of the chain (+/- LSB for rounding errors). Explicit 64bit volume control is a nonsense audiophiles want to see, that's why the softwares do it. CDSP does it because it runs the whole complicated DSP at float64 (where it makes perfect sense because DSP does thousands of operations on the same sample with tiny coefficients where rounding errors add up quickly - unlike volume operation which is a single division on each sample).

Yes may be you are right it is not Audible, but still how to get the noise out of my tweeter when the Analoge Domain Amplification Chain stands whide open?

If you put and Resistor Devider let say Poti 10k at 50% in front of an Amp In, you also devide the rush Noise by this factor? Or not?
If you do volumecontrol by 50% digitaly befor the DAC and than from Analogue Out to AMp The Analogue in on Amp is still 100% open? or not?
Or why i have now this rush noise on tweeter but befor with the same Amp with Najda DSP (Analogue Controled) i didn't.
Or may be it is because i used Asymetrical Conection and now full Symetric
its 4Vrms instead of 2Vrms I am Confused now

Robert

 

[phofman]

Robert, I am not comparing digital vs. analog volume control, but digital in the player/DSP vs. digital in the DAC. Volume control in vast majority of DACs is digital too.

If your tweeters hiss at zero volume, simply your analog chain (including the DAC) is electrically too noisy. Of course analog volume behind the DAC will attenuate the DAC noise (and introduce its noise). It depends on your setup what is better.