Ian asynchronous I2S and S/PDIF FIFO KIT group buy

[iancanada]

Hmm, I got a question. I've got a flea clock that I was going to use in another dac. I'm not sure what the clock frequency is, but can I get away with using just a single 12mhz clock?

Supports 44.1 KHz, 48 KHz, 88.2 KHz, 96 KHz using XOs with different frequencies, MCLK is fixed at 256*Fs. This is for the single clock board.

Dual clock is somewhat more flexible, but the clock has to be a multiple of 44.1 or 48kHz.

Albeit it is asynchronous, the clocks must be within reasonable tolerance from the input clock, so not to over- or underrun the FIFO. It's not an asynchronous sample rate converter!

So....no, 12MHz just doesn't do it.

Hi merlin2069er,

Zinsula answered your question with perfect. FIFO is not a ASRC, that is a different story. .

Thanks zinsula.

Have a good night guys.

 

[roger57]

Hi Roger57,

Sorry for the late reply. qusp, zinsula did perfect answers. Thank you so much guys!

If you just want to stick with only one Fs, says 44.1Khz, then you just need the FIFO KIT which attached with the single clock board originally. Maybe I could try to upgrade the software to make it support another default X Fs setting, which might be 512*fs, in this case, you get chance to use the 22.5792MHz CCHD957( the RMS period jitter is less than 2ps) on the single clock board. I know it's very hard to find a really nice 11.2896MHz oscillator.

Again, FIFO makes good clock working, as well as the bad. So, finding out a really nice clock is a even more important job than the FIFO itself.

Have a good night.

Hi Ian,

Thank you for your polite and courteous answer, which really answers my question. As I suspected - I cannot use a 22.5792MHz crystal for my application (44.1KHz TDA1541A) unless the FIFO is changed to accommodate it. (seems like you've got lots on your hands so I won't ask for that)

I will stick with the FIFO and supplied clock board, get the CCHD957 and I will make an adapter with a D-Flop like the NL17SZ74 to divide the clock down. Seems that might be the only hardware solution that will give better performance than the stock oscillator?

Ian, I'll PM you with the details for my order, thanks again.

Gary

 

[zinsula]

[...]
I will stick with the FIFO and supplied clock board, get the CCHD957 and I will make an adapter with a D-Flop like the NL17SZ74 to divide the clock down. Seems that might be the only hardware solution that will give better performance than the stock oscillator?[...]

I'd buy a clock from Guido Tent -Tentlabs, scroll down the page, you'll find the needed 11.2896MHz XO.
Performance is very good and i'd say it will come out as good as a Crystek CCHD957 with D Type Flip Flop to divide the clock frequency.

 

[lindamar]

Hi Ian

My order arrived safe and sound, what a wonderful packaging !. Very well designed boards, excellent job in every front. Thank you, I am very grateful.

But I am afraid I should have ordered the SPDIF board as well. Do you happen to have 1 spare ?

Best regards
Pepe

 

[qusp]

good choice, the spdif board is excellent, i'm having very good initial results, i'm using a dual ZO scientific conversions input transformer, not cheap but hard to beat. ive used a bit of a hack to install it as its an SMD device with pins similar to soic, any chance you did up any adapters Ian? or did you just use their PTH versions? afaik these top of the line scientific conversions models are not available in the PTH package.

 

[iancanada]

Hi Ian

My order arrived safe and sound, what a wonderful packaging !. Very well designed boards, excellent job in every front. Thank you, I am very grateful.

But I am afraid I should have ordered the SPDIF board as well. Do you happen to have 1 spare ?

Best regards
Pepe

Hi Pepe

I'm happy you like the KIT.

Since I made the S/PDIF boards as same quantity as the FIFO boards, so I still have some in stock. Thay are ready for delivery. You can order it now.
Could you pleas calculate the total by yourself with an email sending to iancanada.mail@gmail.com ? You can make the payment after I confirm it.

Thank you and have a good day.

 

[andrea_mori]

Order

Hi Ian,

meanwhile I order:
- 1 x I2S FIFO KIT
- 1 x S/PDIF Interface Board

then I hope you can help me to feed directly SM5842.

I'll send you an e-mail to confirm order.

Andrea

 

[qusp]

@ roger57:

afaik adding a flip flop will not improve the accuracy, flip flops can be used to improve accuracy of incoming signals, but to do this they need to be clocked by the incoming signal or an external signal... they add jitter, although the good ones only add a very small amount.

all in all looking back I think its good for many interested only in redbook that this particular detail came up, because its true even though the info was there in the manual the full ramifications of something like this could easily be overlooked; even when reading the datasheet..... I would think it should be fairly straight forward to make the change in the firmware to allow the standard single clock board to be set at 512x FS rather than 256 on request; given the calls are obviously already in place for use with the dual XO board? as this may not be an uncommon request it may pay to have it as an option?

@ Ian: i'm clueless as to the time involved in that Ian, so i'm not taking your time for granted there

 

[roger57]

I'd buy a clock from Guido Tent -Tentlabs, scroll down the page, you'll find the needed 11.2896MHz XO.
Performance is very good and i'd say it will come out as good as a Crystek CCHD957 with D Type Flip Flop to divide the clock frequency.

Good suggestion, and that could work...as long as it's a pin for pin substitute and has the required electrical characteristics including drive current. I'll check that out...

 

[iancanada]

@ roger57:

afaik adding a flip flop will not improve the accuracy, flip flops can be used to improve accuracy of incoming signals, but to do this they need to be clocked by the incoming signal or an external signal... they add jitter, although the good ones only add a very small amount.

all in all looking back I think its good for many interested only in redbook that this particular detail came up, because its true even though the info was there in the manual the full ramifications of something like this could easily be overlooked; even when reading the datasheet..... I would think it should be fairly straight forward to make the change in the firmware to allow the standard single clock board to be set at 512x FS rather than 256 on request; given the calls are obviously already in place for use with the dual XO board? as this may not be an uncommon request it may pay to have it as an option?

@ Ian: i'm clueless as to the time involved in that Ian, so i'm not taking your time for granted there

qusp,

For sure, I will upgrade the FIFO verilog code to support an optional default 512*fs setting (256*Fs or 512*Fs jumper selectable), the single clock board user will gain from it by more flexible clock frequency choices. But if you attach the dual xo clock board to the fifo, that board will take over the *Fs control. So, no change to the dual clock board application.

That would be one of the nice improvements.

Thanks qusp, appreciate for all of those super clear answers.

 

[qusp]

yep, jumper would be perfect. I would expect anyone sticking with a single clock board will be doing so because they are only interested in redbook. I cant imagine, for example someone wanting to have 88.2 or 96 permanently. I suppose if they are using an upsampler they might, but it would seem unlikely that they would be buying the fifo.

I wouldnt say my posts are perfect, i'm definitely guilty of being less than perfectly patient

 

[roger57]

yep, jumper would be perfect. I would expect anyone sticking with a single clock board will be doing so because they are only interested in redbook. I cant imagine, for example someone wanting to have 88.2 or 96 permanently. I suppose if they are using an upsampler they might, but it would seem unlikely that they would be buying the fifo.

I wouldnt say my posts are perfect, i'm definitely guilty of being less than perfectly patient

I'm thankful for everyone's help and time...it's about learning, helping...and the music. That's what's great about DIY Audio.

 

[iancanada]

Ian I2S FIFO GB second run is open

Hi guys,

Since more people want the FIFO KIT, I'm afraid I have to open the second run.

If more then 30 on the waiting list, I'll start to order 50 with 20 reserved. I'm trying to finish upgrading the KIT to support more input and output format. Upgrading will be only verilogHDL code related. Hardware keeps no change for sure. User's manuals will be upgraded either before getting ready for delivery.

Waiting list so far:

JamesHill 1*I2S FIFO KIT 1*Dual XO Clock board
chansiukwing
lordvader 1*I2S FIFO KIT 1*Dual XO Clock board
karvid 1*I2S FIFO KIT 1*Dual XO Clock board
Blitz 1*I2S FIFO KIT 1*Dual XO Clock board
daanve -I2S FIFO KIT -Dual XO Clock board -S/PDIF Interface Board
Turbon -I2S FIFO KIT -Dual XO Clock board -S/PDIF Interface Board
KlipschKid 1*I2S FIFO KIT 1*Dual XO Clock board
merlin2069er 1*I2S FIFO KIT 1*Dual XO Clock board
jsh1058 -I2S FIFO KIT -Dual XO Clock board -S/PDIF Interface Board
roger57 -1*I2S FIFO KIT 1*Dual XO Clock board
andrea_mori - 1 x I2S FIFO KIT - 1 x S/PDIF Interface Board (need support left-justified format for SM5842)
Ryan
jsh1058 1 I2S FIFO KIT, 1 Dual XO Clock board, 1 S/PDIF Interface Board


Please let me know if I miss anything.

Have a nice weekend.

 

[KlipschKid]

No hurry for me Ian so I'm happy to wait for an upgraded firmware version. Thank you very much !

 

[ryanj]

Hi Ian,

Could i update my order to 1*I2S FIFO KIT 1*Dual XO Clock board.

Many Thanks, great work.

 

[iancanada]

Hi Ian,

Could i update my order to 1*I2S FIFO KIT 1*Dual XO Clock board.

Many Thanks, great work.

Updated Ryan. Have a nice weekend.

 

[qusp]

if I run 2 x fifo boards from the same dual XO board, I can have 4 channel fifo?

 

[hochopeper]

* I still have 10 pieces of prototype CCHD957 adapter PCB left, First 10 buyers will get one of them for free.​

Ian, what're the chances that a future batch could include more of the CCHD957 adapter PCB?

 

[regal]

both of them work for 44.1, even 90.14xx will work (notice all are multiples of 11.28xx). it depends on your dac. the fifo board will accept 128, 256 and 512x FS, but the single XO board will only output 256x FS unlike the more flexible dual.

but look, here I am doing your research for you, not even sure which dac you are planning to use it with and all of that was in the manual. it seems like we might have a problem here, in that you dont understand the manual, or how i2s works so reading it does not mean anything to you? thats cool, everyone has to learn sometime.

Ian and the thread can only do so much and I/we do want to help, but I know that I would rather help you help yourself; if you want to apply this in your dac, you should be making it your business to find out by understanding the (rather simple really if you take the time) way the sample rate, clock and i2s signals relate to each other and how that applies to your dac. otherwise IMO you have bitten off more than you can chew. its one thing to say I dont read the manual unless there is a problem (silly way to go about it anyway if you were serious) but if you then expect the thread to keep checking the details and regurgitating them for you..well... it gets old pretty quick

IMHO, The logical conclusion is to have a +5V option for the 256fs clock/reclocker board for the RBCD single clock version. The 256fs was the standard for hundreds of top notch CDPers for years, moving to 512x is only going to increase jitter at the DAC conversion (no matter how good the clock choice) plus the RBCD DAC's don't really want 3.3V I2S. Most customers aren't really into hirez modern DAC's anyway. Again just my perspective.

 

[qusp]

Tell Ian, how do you you suppose I have any real influence/power, or interest in this decision that others do not? better that you catch up to the point we ended at, the part where I said most people using the single clock board will be using 44.1 and that perhaps it should be flexible, which followed with discussion ending in the next board revision having jumpers to set FS?

or would you prefer I stayed out of it?....

Most customers aren't really into hirez modern DAC's anyway. Again just my perspective.

yeah it looks that way....