Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter

Here is the TransportPi boards comparison

TransportPi comparison
TransportPi DigiHdmiPiTransportPi MkIIHdmiPi ProTransportPiAES
Descriptionaudiophile grade High performance low cost master mode all in one digital interface transport,Dedicate HDMI transport at low costaudiophile grade All in one SYNC mode digital interface transport,Flagship dedicate HDMI transport. Highest performance so farFlagship dedicate S/PDIF,AES transport. Highest performance so far
key technologies1. On-board local XOs with sockets
2. Master mode all-in one integrated transport
3.1-bit/multi-bit last stage re-clock
4. Low cost no need Fifo
5. So far the great signal quality S/PDIF digi transport
Standard multi-bit LVDS driver1. All-in-one integrated transport
2.1-bit/multi-bits last stage re-clock
1. Low noise discrete LVDS drivers
2. 1-bit discrete low-jitter last stage I2S/DSD re-clock
3. Enhanced power supply filter network
4. So for the best I2S over HDMI signal quality
1. Low noise discrete S/PDIF, AES drivers
2. 1-bit discrete low-jitter last stage S/PDIF, AES re-clock
3. Enhanced power supply filter network
4. So far the best S/PDIF, AES signal quality
Working ModeMasterSYNCSYNCSYNCSYNC
OutputsRCA S/PDIF,
OPT SPDIF
I2S over HDMI
I2S over HDMIRCA S/PDIF,
BNC S/PDIF(Direct Drive) ,
OPT SPDIF
I2S over HDMI
I2S over HDMIAES balanced output
RCA S/PDIF,
BNC S/PDIF(Direct Drive) ,
OPT SPDIF
Native DSD supportDoP onlyDSD/DOPDSD/DoP for Hdmi output, DoP for S/PDIFDSD/DoPDoP only
Local XOsYes, 45.1584/49.1520 Mhz or 22.5792 /24.5760 MhzUse FifoPi's high quality local MCLKUse FifoPi's high quality local MCLKUse FifoPi's high quality local MCLKUse FifoPi's high quality local MCLK
If need a FifoPi to work?NoRecommended but not a mustNeed a FifoPi to functionNeed a FifoPi to functionNeed a FifoPi to function
Need a linux driverYesNoNoNoNo
IsolatorNoAs long as FifoPi has a isolatorAs long as FifoPi has a isolatorAs long as FifoPi has a isolatorAs long as FifoPi has a isolator
Great for low cost compact size digi transportFor all kinds of DACs with HDMI inputGood for all kinds of audiophile DACsGreat for hi-end DACs with HDMI inputGreat for hi-end DACs with S/PDIF input
Power supply optionsShare with RPi or dedicated clean 5V or 3.3VShare with FifoPi Clean power or dedicated clean 5V or 3.3VShare with FifoPi clean power or dedicated clean 3.3V directShare with FifoPi clean power or dedicated clean 3.3V directShare with FifoPi clean power or dedicated clean 3.3V direct
 
Last edited:
Hi everyone,

I am new to DIY audio and new to Ian's audio boards.
Recently I have assembled small Transport Pi Digi streamer with Pure PI.
I have a problem with powering Transport Pi Digi board using battery power from Pure Pi.
Unfortunately I didn't notice that one of the clocks was put backwards before powering up the streamer.
I already got a message from Ian to look at the fuse on Transport Pi Digi. But I don't know where it is. and how it looks like
Could someone show me somehow what am I looking for?

I would appreciate your help.

Pawel
Hi all, it turned out that it was a fuse on Pure PI not Transport PI Digi. I was able to find it myself. It seems to be shot so I ordered new one.

I hope that this will fix my problem.
 
clocks_3.png



I have sort of promised a friend of mine that it would be possible to
connect an additional 2ch dac (BuffaloIIIse) to this clock solution.😳
Now I'm not so sure, even if there is some MCHstreamer firmware
that indicates something fairly close. If someone has a better clue
to this please let me know 😎
 
Ian,

In the table you indicate that the TransportPi MkII requires a FIFOPi to function. You recently shared a remote Pi stack with a PurePi/Pi/IsolatorPi/HDMIPi. I was planning to use the HDMIPi with my original TransportPi since I already have it. I will have the FIFOPi at the DAC. So will the TransportPi not function without the FIFOPi?
 
Dahlberg,

So the signal would be completely separate from the 8 ch I2S signal? You could easily send a duplicate D2 signal, but that may not be what you are looking for. Not real sure that mixing the I2S clocks with SDIF will work well. I would think that the SDIF data would be able to be passed through on D6, just not sure if that will give a better outcome than just connecting the MCH streamer SDIF to the Buffalo IIIse input SDIF.
 
Dahlberg,

So the signal would be completely separate from the 8 ch I2S signal? You could easily send a duplicate D2 signal, but that may not be what you are looking for. Not real sure that mixing the I2S clocks with SDIF will work well. I would think that the SDIF data would be able to be passed through on D6, just not sure if that will give a better outcome than just connecting the MCH streamer SDIF to the Buffalo IIIse input SDIF.
But still keeping all of the clock connections ?
 
Ian,

In the table you indicate that the TransportPi MkII requires a FIFOPi to function. You recently shared a remote Pi stack with a PurePi/Pi/IsolatorPi/HDMIPi. I was planning to use the HDMIPi with my original TransportPi since I already have it. I will have the FIFOPi at the DAC. So will the TransportPi not function without the FIFOPi?
TransportPi works in SYNC mode with need MCLK. So it doesn't work without FifoPi.
You can use a HdmiPi which is not expensive.
 
View attachment 1245509


I have sort of promised a friend of mine that it would be possible to
connect an additional 2ch dac (BuffaloIIIse) to this clock solution.😳
Now I'm not so sure, even if there is some MCHstreamer firmware
that indicates something fairly close. If someone has a better clue
to this please let me know 😎
The diagram looks good.
So, what the question is?
 
Full function FIFO DDC project

RaspberryPi free DDC. I prefer to use RPi remotely. However, the RPi can be installed at any time by just simply plug-in.

1. FifoPi Q7
2. TransportPi AES or HdmiPi Pro
3. ReceiverPi DDC
4. StationPi SMT
5. MonitorPi Pro
6. GPIO extension KIT

This is my current configuration to drive my Spring3 R2R DAC.
Clocks have been upgraded to SC-Pure 45/49.
It need only two power supply, 5V and 3.3V
3.3V is the most significant one so I use a UcPure.

 
@iancanada , please tell us what is your recommendation regarding the pins of SC-PURE clocks which seems to be too thin for the FIFO sockets as many users already reported here (even the clocks are falling out of the sockets if board upside down) 🤔
Thank you!
SC-Pure pins are in standard 0.55mmm which fit the FifioPi socket. However, the socket can get loose if had ever installed XOs with bigger pins.
However the SC-Pure performance can be degraded if the connections are poor.
If that's the case, the best way is to replace the FifoPi SMT XO socket. That's not difficult. Just remove the old ones by cut the pins using a side cutter, and solder two new sockets to the footprints.
You can find the #45A XO socket replacement from my GetHub.

Ian
 
  • Like
Reactions: crm75