Ian asynchronous I2S and S/PDIF FIFO KIT group buy

[roender]

Ian,

Sorry for not reading all the specs when I put myself on the waiting list for FIFO, Dual XO and SPDIFF interface, but I have to pass this GB now.


Kind regards,
Mihai

[qusp]

and?… where is this 90.3168? like I said I already have 45.1584MHz. its the 90.3168/98.304MHz thats rare, with only the NDK as a standard part. then we face the current lack of 2048x mode. A quad XO board, or a clock that can switch speeds on the fly is what is needed to handle the full 44.1/48->352.8/384kHz sampling rate range.

I have to be clear for those who are reading, its only if you want the full 352.8/384kHz capability while maintaining the 44.1/48kHz that you have a problem; the 176.4/192kHz speeds are well catered for as is.

of course there is another solution; I/we can use puremusic or similar to upsample the 44.1/48kHz content before the signal is sent.

[daanve]

#6 paid yesterday - no info in paypal notes. Thank you.

[roender]

This is the measured phase noise of SI570 extracted from here: Si570 Kit from K5BCQ

IMHO, not suitable for audio :-)

[necplusultra]

#21 paid

[qusp]

funny that its already been used pretty successfully in audio. all clocks get worse as the frequency goes down and the crystek is no exception, the crystek is an extraordinarily good XO and has quite a bit better performance down low. It does not come in suitable speeds to solve the very particular problem i've been talking about since the post on the previous page, a problem you have not offered an alternative for. we all have access to the datasheet, posting excerpts from it tells me nothing the thread (anyone whos interested enough), myself or Ian dont know

now unless you are going to post an actual alternative, please leave it alone and do not post on the subject again. I shouldnt even be replying, you are free to not use it.

[roender]

Originally Posted by qusp

funny that its already been used pretty successfully in audio. all clocks get worse as the frequency goes down and the crystek is no exception, the crystek is an extraordinarily good XO and has quite a bit better performance down low. It does not come in suitable speeds to solve the very particular problem i've been talking about since the post on the previous page, a problem you have not offered an alternative for. we all have access to the datasheet, posting excerpts from it tells me nothing the thread (anyone whos interested enough), myself or Ian dont know

now unless you are going to post an actual alternative, please leave it alone and do not post on the subject again. I shouldnt even be replying, you are free to not use it.

Would you please specify where is used? In which project here at diyaudio or elsewhere?

Please compare it with this:
XO
or, from the same manufacturer but dedicated for audio:
http://www.crystek.com/crystal/spec-...k/CCHD-957.pdf

My point is clear: si570/571 proposed by you isn't suitable for audio. It is just a generic XO with a variable output frequencies.

The alternative is to have a FIFO with software able to accept all DSD and PCM formats. There is something in this forum able to do that but from other perspective - SDtrans384
This doesn't means that this project isn't valuable. It's beautifully conceived but not complete (IMHO)

[CeeVee]

#39 paid

Thanks Ian

[iancanada]

Originally Posted by roender

Ian,

Sorry for not reading all the specs when I put myself on the waiting list for FIFO, Dual XO and SPDIFF interface, but I have to pass this GB now.


Kind regards,
Mihai

Thanks Mihai for letting me know. You can quit GB II I don't have problem. Come back at any time to me if you want.

Regards,

Ian

[iancanada]

Originally Posted by roender

This is the measured phase noise of SI570 extracted from here: Si570 Kit from K5BCQ

IMHO, not suitable for audio :-)

Hi Mihai,

Just a kindly discuss with you. I saw that phase noise plot long times ago. But I don’t know if you noticed the testing condition. The guy did the test by a R3463 spectrum analyzer , not a phase noise analyzer. He clearly mentioned that he had limitation on close-in phase noise measurements. That means the close-in phase noise result was not accurate. However the Si570 phase noise floor won all other reference oscillators which was true. So, I list the link of where the plot originally came from just in case there was any misleading by it.
http://www.cliftonlaboratories.com/si570_kit_from_k5bcq.htm

I attached the rated phase noise performance of Si570 from Silicon Labs official documents. It’s -112 dBc/Hz at 100Hz and -150dBc/Hz at 10Mhz, sounds not that bad. At least, among all the XOs with programmable output frequency, it one of the best.

I don’t know what kind of XO you are looking for, as you said, suitable for audio application. Actually I have all of the four XO oscillators you mentioned, CCHD957, Si570, NDK, TentLabs J. I did very careful test and comparing between them. But I would not post the result. Because too much personal preference. I’ll leave this part to other members, as well as the funs. I pay respect to their knowledge and their ears. I don’t think you’ve already experienced Si570 for it need a firmware driver and an evaluate board, but I’m highly suggesting at least doing a comparing test between the other three. The result would be very interesting.

BTW, Si571 is a different story. It has an analog frequency feedback control input Vc which is very easy to introduce phase noise. It results in 30dBc/Hz worse than the Si570 on close-in phase noise performance. So I’ll not take Si571 into account.

Again, it’s just an open discussing. I’m toleranced with different idea. As R&D engineer, I always tend to do something ‘real’ with talking lessJ.

Regards,

Ian