Ian asynchronous I2S and S/PDIF FIFO KIT group buy

[qusp]

Originally Posted by regal

Few questions:

1. The spdif board came with only one BNC cable, I was assuming this wasn't as important (since its pre-Fifo) and would use the FPC/FFC 1.0mm ?

depends on how you feel about it, myself i'll use the bnc for both, but yes you can use the supplied ribbon cables

2. I did order an extra set of the BNC cables for the final I2S output. But I need a set of the micro-bnc sockets for my DAC board, anyone have a digikey or Mouser part number ?

regal, you have the cable part number right? you know how to use search at digikey and mouser dont you? at digikey in the bottom left there is a list of associated and mating part numbers and at mouser there is a list along the bottom of 'the people who bought this, also bought...' or you could just search for u.fl at either of these places, or you could look for one of the other 20 times this question has been asked/answered (ive answered it a number of times myself). i'm not being critical there mate, youre smarter than that and i know your not lazy, i'm just giving you a nudge.

3. Also I just need confirmation that the spdif board and the fif/reclock have good regulation on board and we just need to supply a decent LM317 DC ?

correct, you could look at tweaks like that further down the line, the onboard regulation, decoupling and filtering is a top notch IC based approach with the highest performance chip regs and R/C/L networks, but with quite some effort and some serious test gear you may have a go at subjective or objective improvement, i dont believe just slapping any discrete reg just because its discrete will make it better. Demians clock PSU in the thread is worth a look when you get that far.

4. Last since this is going to be RBCD only, do I need to change the crystal on the spdif board (24.576 mhz) to a 512x44.1= 22.5792 clock, I am confused as to the choice of 48x512 for that crystal

you dont need to no, as everything is reclocked, but its probably desirable yes. that clock board you have there was only really meant for testing and getting the device set up, like the spdif transformers, Ian expects anyone serious about sound to replace the XO with something higher quality of their choice, or buy the dual clock board and do the same; not a chance to please everyone, the crystal is just a placeholder really, do with it as you see fit.

Please bear with me and I apologize for all the question but working wihout a schematic (completely understand why) is a bit of a challenge for how I normally put together a project ?

in all honesty even apart from the IP issues, the average user would only make performance worse 'tweaking' this board; it runs at much higher speed and with a completely different methodology than traditionally used in diy audio kits and less than well dressed leads or less than neat soldering could easily cause issues, it would be like taking the soldering iron to your CPU in the hope of improving performance. there will be some tweaks to play with by the more advanced user, but mostly they would/should involve using different regs entirely, or using elaborate clocks, batteries etc. i dont expect mods like beefing up caps, or my particular favorite replacing terrible sounding SMD components with leaded audiophile components that perform an order of magnitude worse, particularly at these speeds; to fly very well.

not suggesting thats what you had in mind

[regal]

No I wasn't planning on modding it, or changing the regulation, just didn't know what I was looking at. Sounds like pre regulated 6V DC from an LM317 will be OK for supply.

I'm not referring to the Fifo crystal which is a 256x44.1 = 11.2896 crystal.

Its the SPDIF input board that has the 24.576 mhz crystal, which is confusing me.

I'm just setting this up for RBCD so the 11.289 quality is fine for me (I am not a believer is spending much effort on exotic crystals, its a losing game for the layman

But I am not familiar with the SPDIF chip, probably the crystal isn't being used unless transmitting ? I bought the spdif board to make things easy, was surprised it can function as an i2s to spdif transmitter, not sure what purpose that serves.


Also found the micro bnc socket part number: J983CT-ND.

thanks

[iancanada]

Originally Posted by qusp

depends on how you feel about it, myself i'll use the bnc for both, but yes you can use the supplied ribbon cables


regal, you have the cable part number right? you know how to use search at digikey and mouser dont you? at digikey in the bottom left there is a list of associated and mating part numbers and at mouser there is a list along the bottom of 'the people who bought this, also bought...' or you could just search for u.fl at either of these places, or you could look for one of the other 20 times this question has been asked/answered (ive answered it a number of times myself). i'm not being critical there mate, youre smarter than that and i know your not lazy, i'm just giving you a nudge.


correct, you could look at tweaks like that further down the line, the onboard regulation, decoupling and filtering is a top notch IC based approach with the highest performance chip regs and R/C/L networks, but with quite some effort and some serious test gear you may have a go at subjective or objective improvement, i dont believe just slapping any discrete reg just because its discrete will make it better. Demians clock PSU in the thread is worth a look when you get that far.



you dont need to no, as everything is reclocked, but its probably desirable yes. that clock board you have there was only really meant for testing and getting the device set up, like the spdif transformers, Ian expects anyone serious about sound to replace the XO with something higher quality of their choice, or buy the dual clock board and do the same; not a chance to please everyone, the crystal is just a placeholder really, do with it as you see fit.




in all honesty even apart from the IP issues, the average user would only make performance worse 'tweaking' this board; it runs at much higher speed and with a completely different methodology than traditionally used in diy audio kits and less than well dressed leads or less than neat soldering could easily cause issues, it would be like taking the soldering iron to your CPU in the hope of improving performance. there will be some tweaks to play with by the more advanced user, but mostly they would/should involve using different regs entirely, or using elaborate clocks, batteries etc. i dont expect mods like beefing up caps, or my particular favorite replacing terrible sounding SMD components with leaded audiophile components that perform an order of magnitude worse, particularly at these speeds; to fly very well.

not suggesting thats what you had in mind

Originally Posted by regal

No I wasn't planning on modding it, or changing the regulation, just didn't know what I was looking at. Sounds like pre regulated 6V DC from an LM317 will be OK for supply.

I'm not referring to the Fifo crystal which is a 256x44.1 = 11.2896 crystal.

Its the SPDIF input board that has the 24.576 mhz crystal, which is confusing me.

I'm just setting this up for RBCD so the 11.289 quality is fine for me (I am not a believer is spending much effort on exotic crystals, its a losing game for the layman

But I am not familiar with the SPDIF chip, probably the crystal isn't being used unless transmitting ? I bought the spdif board to make things easy, was surprised it can function as an i2s to spdif transmitter, not sure what purpose that serves.


Also found the micro bnc socket part number: J983CT-ND.

thanks

Thanks qusp,

Hi regal,

I post some answer here:
http://www.diyaudio.com/forums/digital-line-level/192465-asynchronous-i2s-fifo-project-ultimate-weapon-fight-jitter-32.html#post2968816

Please let me know for any question.

Nice weekend.

[iancanada]

Hi guys, all of the KITs were run out. If you are really interested in this fifo project, please register here for the second run. If more than 30 people want, I will start another production.

Thanks

[chansiukwing]

please count me, i am interested in it.

[bigpandahk]

Hi Ian

As I can only use USB to connect my DAC, how can I connect your S/PDIF board to my Mac via USB? Or I have to use the WM2902 in my DAC and connect the S/PDIF output from 2902 to your S/PDIF board for re-clocking and connect the FIFO output back to the WM8741?

[iancanada]

Originally Posted by bigpandahk

Hi Ian

As I can only use USB to connect my DAC, how can I connect your S/PDIF board to my Mac via USB? Or I have to use the WM2902 in my DAC and connect the S/PDIF output from 2902 to your S/PDIF board for re-clocking and connect the FIFO output back to the WM8741?

Hi bigpandahk,

If you have the S/PDIF board, you can connect to a Mac directly by the optical cable into the s/pdif board. fifo replaces the clock, so it dosen't matter from optical or coaxial.

If you still want to connect to a usb, you can connect either from s/pdif output of that usb into spdif board, or from its I2S output into the fifo board (in this case you don't need the spdif board). Your DAC should be always connected directly to the clock board via I2S.

However, if you want to setup a s/pdif fifo, that would be other story.

You have a lot of options. Having fun with the KIT.

[lordvader]

I'd be interested in a FIFO kit and a dual clock board.

Quick question. I'm considering using this as part of a USB dac. If the USB->I2S interface has a single clock, will the dual clock board "fix it", or will it be better to use a single clock in that scenario ?

[iancanada]

Originally Posted by lordvader

I'd be interested in a FIFO kit and a dual clock board.

Quick question. I'm considering using this as part of a USB dac. If the USB->I2S interface has a single clock, will the dual clock board "fix it", or will it be better to use a single clock in that scenario ?

USB usually generates various Fs I2S signals, for example, 44.1K,96K,192K....
You have to use dual xo clock board to match them. If the oscillators you will use have less jitter than the clocks from USB, the quality of the sound will get improved.
Thanks for interesting.

[karvid]

Hi Ian,
I'm interested in a FIFO kit and a dual clock board.