Author Topic: HAL Music Server experiment for I2S Bus interface  (Read 2722 times)

Offline HAL

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HAL Music Server experiment for I2S Bus interface
« on: February 09, 2021, 06:16:11 AM »
For years, have been very happy using an I2S Bus interface to DAC's like the original Audio Alchemy DDEV3 and Perpetual Technologies P3A DAC units.  Both had large sound improvements over the coaxial S/PDIF.

I have seen the PS Audio I2S Bus over HDMI, but that will not work with the older devices, and most modern DAC's have the original style I2S Bus interface on the chip.

The Raspberry Pi style DAC HAT's use the I2S Bus interface on the GPIO to drive DAC's directly.  You use a dedicated music OS like Volumio or Moode to do the playback as the RPi4 has some dropout problems when running full Raspbian Buster OS as I have tried.  Not big on Linux, so time to try something else.

It is time to try this with a SBC that runs Windows 10 64bit OS and see what happens with I2S Bus as there are now GPIO available on some of them.  A few things need to be added, but that is very straight forward these days to have high quality audio.

With Windows 10 music players like Foobar2000, JRiver MC27 work well so those will be the starting points.  Both support things like room correction, headphone correction and room measurements.  Other programs like Room EQ Wizard will also run and can be used.  For recording from analog sources, Audacity has been very good as well.

Hardware is here for trials, so will post as testing begins in this thread.

Offline Nick B

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #1 on: February 09, 2021, 10:16:28 AM »
Thanks for the update, Rich.
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Offline P.I.

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #2 on: February 09, 2021, 11:58:55 AM »
Good deal.  I2S is the best interface I've heard.  I'll be interested in how this all goes...
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Offline HAL

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #3 on: February 09, 2021, 07:33:20 PM »
Nick and Dave,
Will be updating as I go. 

Might be writing a device driver, so that should be interesting. :o

Waiting on the 5-pin Mini-DIN connectors to arrive to reuse the old AA I2S Bus cable and the Revelation Audio ones.  As you know parts delivery is going very slllllllloooooooooowwwwww! :(

Rich

Offline P.I.

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #4 on: February 09, 2021, 08:03:00 PM »
Nick and Dave,
Will be updating as I go. 

Might be writing a device driver, so that should be interesting. :o

Waiting on the 5-pin Mini-DIN connectors to arrive to reuse the old AA I2S Bus cable and the Revelation Audio ones.  As you know parts delivery is going very slllllllloooooooooowwwwww! :(

Rich
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"A man with an experience is never at the mercy of a man with an argument." - Hilmar von Campe

Offline Nick B

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #5 on: February 09, 2021, 10:29:55 PM »
Nick and Dave,
Will be updating as I go. 

Might be writing a device driver, so that should be interesting. :o

Waiting on the 5-pin Mini-DIN connectors to arrive to reuse the old AA I2S Bus cable and the Revelation Audio ones.  As you know parts delivery is going very slllllllloooooooooowwwwww! :(

Rich

Rich,
I was watching a YouTube video last night and there was a comment as to I2S not having a firm implementation standard (not sure I phrased that correctly) Can you comment on that?
Nick
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Offline HAL

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #6 on: February 10, 2021, 04:34:33 AM »
Nick,
The I2S Bus started as a direct way to talk to a DAC chip, so each mfg had their own ideas.  It is meant to be a direct interface with data and clock separate to not have to recover them like in S/PDIF.  This was meant to be short connections on a PC Board.   The data rates are high, so the wiring is usually layed out as RF style connections. These are still well below anything like a eSATA interface data rates.

The first implementation of an external I2S Bus interface that I had seen was the Audio Alchemy version with the 5-pin Mini-DIN connector on their DAC's, transports and signal processors.  I had them all and was very impressed with the sound quality.  Another group to use it is Constellation Audio as Peter Madnick from Audio Alchemy and Perpetual Technologies is one of the designers on their Music Server.  First I knew of with the I2S Bus to external audio DAC's.

There is an I2S Bus standard that uses differential signal interface with an HDMI connector that was published that companies like PS Audio use.  This helps with longer interface cables, but it adds complexity to the design. 

With a well thought out cable and connector system a short shielded cable works well for the original style I2S Bus wiring.  Audio Alchemy used the Mini-DIN and shielded cable that worked well, so will use that for this experiment.

Offline Nick B

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #7 on: February 10, 2021, 12:33:03 PM »
Nick,
The I2S Bus started as a direct way to talk to a DAC chip, so each mfg had their own ideas.  It is meant to be a direct interface with data and clock separate to not have to recover them like in S/PDIF.  This was meant to be short connections on a PC Board.   The data rates are high, so the wiring is usually layed out as RF style connections. These are still well below anything like a eSATA interface data rates.

The first implementation of an external I2S Bus interface that I had seen was the Audio Alchemy version with the 5-pin Mini-DIN connector on their DAC's, transports and signal processors.  I had them all and was very impressed with the sound quality.  Another group to use it is Constellation Audio as Peter Madnick from Audio Alchemy and Perpetual Technologies is one of the designers on their Music Server.  First I knew of with the I2S Bus to external audio DAC's.

There is an I2S Bus standard that uses differential signal interface with an HDMI connector that was published that companies like PS Audio use.  This helps with longer interface cables, but it adds complexity to the design. 

With a well thought out cable and connector system a short shielded cable works well for the original style I2S Bus wiring.  Audio Alchemy used the Mini-DIN and shielded cable that worked well, so will use that for this experiment.

Thanks for the explanation, Rich. Very interesting
Nick
Orchard Starkrimson Ultra amp
Supratek Chardonnay preamp
JMR Voce Grande speakers
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Audio Envy p cords
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Offline HAL

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #8 on: February 11, 2021, 07:34:20 AM »
For the experiment have a 4 channel DSO setup running to the SBC computer.  Testing all 4 channels and good to go.

Now to setup the I2S Bus wiring into the DSO for trials.

The Windows 10 HAL I2S Bus audio driver will be in testing with this setup.
« Last Edit: February 11, 2021, 07:36:55 AM by HAL »

Offline HAL

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #9 on: February 22, 2021, 08:12:44 AM »
Here is a picture of the HAL MS-6 before the I2S Bus 5-pin mini-DIN connector installation.  First cable prototype done and ready for trials.

The quarter is for system size reference.

Uses a GaN based SMPS AC power supply.  Full CPU power is 13watts and normal operation is 6watts total system power dissipation.
« Last Edit: February 22, 2021, 10:00:10 AM by HAL »

Offline HAL

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #10 on: February 24, 2021, 02:40:08 AM »
The system I am going to modify for I2S Bus input is the DODD AUDIO DAC using the Wolfson WM8741 IC.  This will get a direct Audio Alchemy style I2S Bus interface to the DAC chip.  This is still one of my favorite sounding DAC's of all time and I have heard a lot of them since the '80s.

I helped Gary with the design of this DAC, so very familiar with what is needed for the mods. :)

Now to see if the I2S Bus mini-DIN connectors will fit in the original USB input cutout.

Offline HAL

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #11 on: February 28, 2021, 08:40:34 AM »
Put the new SBC into a HAL MS-1 chassis that had a lightning strike at a customers place and swapped out systems.   Gutted the chassis and put the new motherboard in that is very small.  Lots of room for test connections to the DSO for testing.

Have the I2S Bus connector installed and trying out a start at the Windows 10 64 bit device driver. 

This is to check output logic levels to see if the interface needs a level translation circuit to the standard 3.3VDC logic.

Offline Nick B

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #12 on: February 28, 2021, 12:18:40 PM »
The system I am going to modify for I2S Bus input is the DODD AUDIO DAC using the Wolfson WM8741 IC.  This will get a direct Audio Alchemy style I2S Bus interface to the DAC chip.  This is still one of my favorite sounding DAC's of all time and I have heard a lot of them since the '80s.

I helped Gary with the design of this DAC, so very familiar with what is needed for the mods. :)

Now to see if the I2S Bus mini-DIN connectors will fit in the original USB input cutout.

Rich,
So the I2S Bus mini-DIN fit ok? Interesting about how good some older dacs sound. I’ve heard some guys really liked the old Stax DAC X1t
Orchard Starkrimson Ultra amp
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Audio Envy p cords
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Offline HAL

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Re: HAL Music Server experiment for I2S Bus interface
« Reply #13 on: February 28, 2021, 01:00:27 PM »
Nick,
The 5-pin MiniDIN connector is the AA style connector and my AA I2S Bus cable fits.  I have an AA I2S Bus wiring diagram and AA DAC's here to try out once I have a Win10 driver working.  Selecting the 5-pin jack for the chassis has many configurations to try with the chassis. 

The one Mini-DIN jack I used with Gary's old DAC fit in the original hole and used the same mounting holes for screws.  That is also a chassis possibility.

Making progress.