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[PROBLEM] DSD 128 and PCM 384 - Printable Version

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DSD 128 and PCM 384 - nicpom - 05-06-2019

Hello,

I am using Moode 3.8.3 since 2017 in Rpi3 B system connected via i2s to IanFifo boards (including DOP to DSD decoder). Playback is through Squeezelite, from a Daphile server.

So far so good: 3.8.3 provides good sound, very stable and support of PCM up to 384 and DSD128. I never upgraded to version 4 because sound was almost the same and DSD128 support was missing.

Recently I tried 5.1 Version, and found a noticeable sound improvement. Unfortunately, DSD128 and DXD (PCM352) are still not supported.

Is there any hope to have them working in a future release? I love Moode sound but the lacking of these formats is a bad limitation for me.

Many thanks


RE: DSD 128 and PCM 384 - Tim Curtis - 05-06-2019

The old 3 series moOde used experimental kernel and I2S drivers that the maintainer abandoned and so they eventually became unsupportable and were dropped and replaced by stock Linux kernel for Raspberry Pi beginning with moOde 4 series. Certain I2S drivers in the stock kernel already support up to 384K PCM rate for example the drivers for Allo Boss and Katana DAC's The Katana also supports DoP. These DAC's play DSD64 and DSD128 perfectly.

For other I2S drivers its up to the DAC manufacturer or driver maintainer to release a driver that supports > 192K PCM rate and then get the driver accepted into the Linux kernel.


RE: DSD 128 and PCM 384 - nicpom - 05-13-2019

(05-06-2019, 07:10 PM)Tim Curtis Wrote: The old 3 series moOde used experimental kernel and I2S drivers that the maintainer abandoned and so they eventually became unsupportable and were dropped and replaced by stock Linux kernel for Raspberry Pi beginning with moOde 4 series. Certain I2S drivers in the stock kernel already support up to 384K PCM rate for example the drivers for Allo Boss and Katana DAC's The Katana also supports DoP. These DAC's play DSD64 and DSD128 perfectly.

For other I2S drivers its up to the DAC manufacturer or driver maintainer to release a driver that supports > 192K PCM rate and then get the driver accepted into the Linux kernel.

Thanks for the answer.

Actually, a driver for IanFifo is listed in ver. 4 and ver. 5 moOde. It seems strange to me that latest drivers are less capable then older ones.

Also, there are players (i.e. Gentoo) that support dsd128 from i2s (on RaspBerry Pi) with stock kernel and generic drivers.

I will try to change driver selection to see if there is one which works better with my hardware.


RE: DSD 128 and PCM 384 - Tim Curtis - 05-13-2019

If the Gentoo player you mentioned in fact is using a stock Linux kernel and i2s drivers then given that the i2s drivers are part of the kernel itself these drivers should already be in the stock kernel used in moOde 5.

Post the contents of /boot/config.txt from the Gentoo player distro. It should list the i2s driver

dtoverlay=


RE: DSD 128 and PCM 384 - nicpom - 05-15-2019

Actually in Gentoo the driver which allowed DSD128 and PCM384 is denominated Sabre. I tried all the DACs on Moode drivers list using a Sabre chip and... Bingo! the Audiophonics ES9028/9038 works!

Selecting that driver instead of the IanFIFO one, I have perfect playback of DSD128 and PCM384 in moOde 5.2.

So far so good, even if I do not know why. I suspect that those IanFifo drivers are not so well implemented...


RE: DSD 128 and PCM 384 - Tim Curtis - 05-15-2019

Thats an interesting result :-)

The driver moOde currently assigns to IanFifo II is just the generic hifiberry-dac driver which only supports up to 192K but that can be changed to use the Audiophonics driver instead.

What exactly are the hardware components in your kit and whats the DAC board?
Do any chip options appear in alsamixer?


RE: DSD 128 and PCM 384 - nicpom - 05-15-2019

With reference to this page:

https://github.com/iancanada/DocumentDownload/blob/master/README.md

I (we are a group actually) am using the IsolatorPi board on top of the RaspBerry Pi3 B, with the DoP to DSD decoder.

Then the signal, which is a 4 wire i2s (Master Clock, LR clock , Bit clock, Data) goes to a McFifo board equipped with a McDualXO clock board. Eventually the re-clocked signal is sent to a I2S-to-HDMI interface board. This is our streamer.
As DACs we are using Denafrips products.

Other FIFO boards are available in that site and they have the same I2S interface.

With Audiophonics driver there are some chip options regarding the antialiasing filter, but they do not have any effect with my hardware.


RE: DSD 128 and PCM 384 - Tim Curtis - 05-15-2019

You should post some pics of the device :-)

I'm still a bit confused as to how the Audiophonics ESS Sable driver is working when the Denefrips DAC's are all based on R2R custom ladder DAC designs.

-Tim


RE: DSD 128 and PCM 384 - nicpom - 05-17-2019

(05-15-2019, 08:35 PM)Tim Curtis Wrote: You should post some pics of the device :-)

I'm still a bit confused as to how the Audiophonics ESS Sable driver is working when the Denefrips DAC's are all based on R2R custom ladder DAC designs.

-Tim

Good question. My guess is that raw I2S data happen to have a format compatible with DAC decoding (which is based on custom FPGA), and the additional data for Sabre chip are stripped away by Ian boards.

Please find below some photo of the streamer (name is Streaminator)

https://drive.google.com/open?id=1j7ZjZXK3G21iYQh2eD3b5YiEEX5gFmYc

https://drive.google.com/open?id=1UUEgBcbiqCVUKsE0U2ZnnM6FXX788aq9

https://drive.google.com/open?id=1MGnAPbDhztfNzVprSAXpSjEB6J1FKOdF