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

Hi Ian,

A question about supported frequencies:
- Can the new FIFO firmware and clock board support 192fs, 384fs and 768fs frequencies?

I was checking SM5847 datasheet page 18 (which I plan to use if I can get my hands on one) and 176.4KHz and 192KHz are only supported on 192fs.

I know that this board cannot support everything but would be a nice feature though.

Thanks,
Zsolt
 
I really think that we are in danger of making this unit useless by everybody throwing their hat into the ring for requests. we have a saying here, not sure of the origin,

'Jack of all trades, master of none'
...can be extended with:
"Certainly better than a master of one"

One is 4x and the other is 3x above the bit clock frequency. Doesn't seem for me such an ex-centric request.
I mentioned, it's a nice to have feature -even if in a future firmware update- like the Left Justified support is in the current.
 
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Upgrading job finished finally. Two weekends were killedJ. New version will include the following features:

1. Optional 32bit left-justified output format support
Reason of this feature: To integrate FIFO with some DSPs or DACs which do not accept I2S input, for example, PMD100, SM5842, SM5843…

2. Optional 16-32bit left-justified input format support
Optional 16bit right-justified input format support
Optional 24bit right-justified input format support
Reason of these features: To interface FIFO with some digital audio frontend which do not output I2S. For example, interfacing with some DIRs from Japanese manufacturers, tapping signals form CDROM…

3. New optional default 512*Fs MCLK support
Only Single XO clock board user will benefit from this feature. Dual XO clock board will take over all the default *Fs settings.
Reason of this feature: Single XO clock board users will have more options to select frequencies. For examples, use 22.5792MHz oscillator for 44.1KHz Fs or 24.5760Mhz for 48Khz, and so on. And same XO will work for 88.2Khz or 96Khz either, just a jumper! :).

All new features are jumper selectable. Only FPGA/CPLD firmware is involved in this upgrading. Hardware keeps no change. If you are happy with I2S and don’t need these new features, then you don’t need making any upgrading. Performance didn’t change any.

Testing FPGA board was upgraded at same time to perform loop test.

I attached the waveform of new support formats just for reference.

Have a good night.

Sounds like the 24 bit MSB first L&R are assessable simultaneously to run a stereo pair of PCM1704? this is great.

But for the PMD100/SM5842 guys who will be redbook only (PMD100/hdcd is redbook) this chip only accepts 256fs and 384fs not 512fs, so I don't think wev'e gained anything here as far as plugging into a classic PMD100 based DAC.
 
I really think that we are in danger of making this unit useless by everybody throwing their hat into the ring for requests. we have a saying here, not sure of the origin,

'Jack of all trades, master of none'

Completely disagree, master of S-D DAC's is all thats alternative to this Fifo now, which to many is a master of none.

There is a lot of potential here which could benefit many who's only option has been a bunch of 90's tech jittery glue logic.
 
get a grip regal, seriously mate, where does the functionality end? its quite incredible how bitter you are and about what? because your precious dac topology is getting passed or over on occasion? I ignored your veiled, threatening, accusatory and deluded PM on behalf of the nos, R2R or external filter? mafia because I didnt want to give you acknowledgement, it was truly funny.

(yes I was PM'd accused of having unnamed ulterior motives and pushing development towards the sabre; told that people were wondering (shill? not sure the accusation was pretty vague) and the hundreds thousands, millions? (bites pinky) of other users and their dacs that must have attention instead and Regal was apparently elected the mouthpiece to pass this friendly message on?; this rant was delivered as if I had some sort of control of the outcome, or other motive other than just liking to use my dac with hardware I have in my possession. ignoring the fact that the thing pushing development in that direction was Ian exploring the limits of the device, an obvious interest in trying the buff/sabre and thus an interest in how they worked together, not me)

so you disagree that endless requests are not productive? I dont see you doing the work, I just see you making the requests to be catered for by a great member who likles to help people and I see him and his time being taken for granted TBH. have you noticed that Ian has actually bought a buff 3? you still think i'm the one pushing development in that direction as an option? I havent posted in here for ages and theres just page after page of different functions and then when I dare to suggest that might be enough I get this ****?

pretty delicious irony dont you think?
 
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Calm down guys.
Apart that, just to make clear, the upgrade is not about L-R splitting, stopping clock etc. which would be necessary for NON OS.
That would be another board which Zsolt and myself have discussed with Ian. You cannot connect the AD or BB R2R DAC's directly.

Btw, it has not to be NONOS.....anyone of you has a suggestion for a software which would oversample 44.1/16 to 88.2.....192 kHz offline and store the files in the new format? So we can avoid the digital filters...
On this website, there are only comparisons of conversions from 96 to 44.1. Is it safe to say that a good "downsampler" is also a good oversampler?
 
what operating system? how about puremusic? I do any upsampling in realtime in general with PM, so cant really report on its offline functionality. it uses 64bit apodising filters, I would assume you wanted apodising?

hey look man, I dont have a specific problem with your request, I just see a LOT of requests/suggestions being made, meanwhile i'm getting very strange messages telling me to back off and telling ME that i'm being selfish and I havent asked for anything in ages, think the last thing I actually asked for (and really it was just a suggestion for improvement) it was the u.fl or w.fl connectors. everything else is just optimizing it for the sabre and i'm hardly the only person using it with ESS, so how does that make me selfish? in fact I was EXPECTED to report on and suggest improvements for the unit with my dacs...which...strangely.... are sabres. sabre sabre sabre sabre sabre 9012, 9018 sabre sabre 9012
 
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Hi Ian,

Nice work and thank you for sacrificing two weekends (at least) for hobby - with a full time job and family I know this is hard :)

I plan to try different digital filters before my AD1865 and will start with DF1704 as that is the easiest to interface with my current setup and FIFO as it supports LVTTL and has I2S input. I would also like to try SM5842(7) and/or PMD100 so I will need the Left Justified output support as well.

Others might have asked: can existing FIFOs be upgraded with your new firmware? You are probably using JTAG for this, for ~15$ there are plenty of AVR JTAG programmers on ebay.

Thank you,
Zsolt

Thanks Vzs,

Upgrading is free. Both re-programming and loop testing are required. I need confirm each bit is perfect for different formats after upgrading. Just send it back to me in a bubbled envelope. That will be much cheaper than in a box. I don't need cables and clock board. Just the FIFO board. I'll sent the upgrated board back to you in the same envelope. That would be easier for both of us. You still keep me address tag?

Regards,
 
Hi Ian,

A question about supported frequencies:
- Can the new FIFO firmware and clock board support 192fs, 384fs and 768fs frequencies?

I was checking SM5847 datasheet page 18 (which I plan to use if I can get my hands on one) and 176.4KHz and 192KHz are only supported on 192fs.

I know that this board cannot support everything but would be a nice feature though.

Thanks,
Zsolt

Hi Zsolt,

The FIFO board support 128,256,512 and 1024fs. Both new and old firmware are. But I can not support 192,384 and 768fs. The internal logic is based on /2,/4,/8/16... If add /3,/6 the Fmax will be suffer. I'm concerned about the performance. :)
 
what operating system?[...]
Windows....XP or 7, so no Puremusic, but thanks for the suggestion.

The reason that i'd like to do oversampling offline is that the music should be played from NAS, without PC, through Network Player with S/PDIF output.
Should work very well for 44.1/16 material (CD's, that's what i have) after oversampling offline.

With my DVD / Sat receiver, the FIFO will not go well together anyway. I can only more or less delay the audio stream compared to the video stream. With the already delayed audio because of FIFO, films will be out of lip sync.

[...]it uses 64bit apodising filters, I would assume you wanted apodising?
Audio quality is said to be good with those filters, i think it's the same as minimum phase filters. Not sure about that.
 
get a grip regal, seriously mate, where does the functionality end? its quite incredible how bitter you are and about what? because your precious dac topology is getting passed or over on occasion? I ignored your veiled, threatening, accusatory and deluded PM on behalf of the nos, R2R or external filter? mafia because I didnt want to give you acknowledgement, it was truly funny.

(yes I was PM'd accused of having unnamed ulterior motives and pushing development towards the sabre; told that people were wondering (shill? not sure the accusation was pretty vague) and the hundreds thousands, millions? (bites pinky) of other users and their dacs that must have attention instead and Regal was apparently elected the mouthpiece to pass this friendly message on?; this rant was delivered as if I had some sort of control of the outcome, or other motive other than just liking to use my dac with hardware I have in my possession. ignoring the fact that the thing pushing development in that direction was Ian exploring the limits of the device, an obvious interest in trying the buff/sabre and thus an interest in how they worked together, not me)

so you disagree that endless requests are not productive? I dont see you doing the work, I just see you making the requests to be catered for by a great member who likles to help people and I see him and his time being taken for granted TBH. have you noticed that Ian has actually bought a buff 3? you still think i'm the one pushing development in that direction as an option? I havent posted in here for ages and theres just page after page of different functions and then when I dare to suggest that might be enough I get this ****?

pretty delicious irony dont you think?

Hi guys,

My question is how many people in the world keep the same hobby? And how many people in this forum could go through all the details of this thread, take consideration and provide their ideas?

All your suggestions are treasured for me. Qusp was a good example. He suggested the U.FL connecters and cables for me which made big progress for the FIFO project to generate better master clock. I'm still full with thanks.

I was an 'old fashion' audiophile. I went through all the old gear in the past, KT88,2A3,300B,WE310,CDM4,CDM9,TDA1541,PCM58,AD1865....But I found some new technologies are not that bad recently, that's why I pay great effort developing this FIFO project. And it's approved! So, I think what I'm doing right now is trying to improve the sound quality by introducing better clock with the FIFO platform, for DACs, DSPs, both new and old.

I love this website, your feedbacks is my motivation. Although I'm still losing money from the GB :), but nothing compare with the pleasure you brought to me.

It seems there are a lot of things need to do the next. So, I'll keep going with this project. Your participation would be always highly appreciated.

Thanks,
 
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Well, it is really sad if you are loosing instead of making money from that GB :(
That device would add a four figure number to the price of a DAC from any well respected manufacturer that advertises in magazines and we would be able to read at least two pages of marketing BS how this is impossible to be made by others...

Ian, we are very thankful for what you offered at such a great price, not to mention that you are still trying to make it better and make everybody happy. Hadn't seen that attitude in a while...

1704 is still in production as is the 9018 and there are people like me that have both, so I feel kind of happy that I don't have to choose :) I have heard great things about the 1862 but I am not going to buy the kit and then go on and try to find the impossible to find at a ridiculous price, not that the aforementioned ones are cheap...
 
Hi Ian,

Thanks for your time developing this and providing support - very good of you !

I'm planning to use this in a few different DACS and I'm sure it'll be fine in all except one - a TDA1543 I2S DAC with sixteen DAC ICs - overload ?

At the moment, the 16 DAC ICs are connected through a 74HC125. There are 8 pairs of DAC ICs and there are 33R resistors at the input on every line into each pair.

Here is the diagram.

An externally hosted image should be here but it was not working when we last tested it.


Any suggestions for making this work at its best ? Thanks very much.
 
If this is like the TeraDAK chameleon it will require the isolated outputs used with 5V logic levels, I remember reading through that mod tread where Steve Nugent(Empirical Audio) modded one of his friend TeraDAC's to use I2S, it also has 16 x 1543, I have one as well and am looking to drive it this way possibly.
So if the FIFO is happy with 5V logic it should be ok.
though from memory Steve only had resistors at each end of the I2S lines.
This also rings true with qusp's observation of the controlled impedance of the u.fl connectors etc.
incorrect termination of I2S causes reflections on the lines which can add "jitter" or "smearing" or some technical term I'm not familliar with, these are usually sorted with a cro.

my two cents.

Drew.
 
Hi Drew,

I was thinking of removing the 74HC125 and using Ian's FIFO instead of it, or keep the 74HC and use Ian's FIFO after it. I want to upgrade to VHC but I can only find so16 size, no dip.

Here's some pics of the DAC (only 8 ICs here but I'm using 16). It uses WM8805 receiver and has an I2S rj45 input too. The circuit diagrams are not 100% accurate.

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.
 
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Another option would be to see if you can run the 5V logic after the FIFO if it wont run 5V TTL, look up reference TDA1541 project(red baron) by dvbprojekt on here, he uses a faster flip flop instead of the 74HC. this may reduce the jitter aspect. Only I an cann tell you
There are adaptor pcb adout and I think dvbproject has some he sells.
This FIFO could only improve the dac I think from what we can read here on peoples responses to hearing it.
I would test but I am in GBII. I hope.

Hope that helps.

Drew.