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

[hochopeper]

Originally Posted by qusp

at least one other project, the widget used the Si parts as one option, though I think they used one of the lower spec parts.

George (yoyodyne) uses the si532 in his es9023 and pcm5102 dacs.

[qusp]

just checked the 5315 datasheet further down, its not as good so we can rule that out.

[hirez69]

Originally Posted by qusp

Ian, could the board or firmware be rejigged to allow the dual clock board to contain say a 45.1584 plus 98.304 XO's? then the only speeds not covered would be 48kHz and 354.x kHz which in my world are pretty rare

great idea, qusp.
do you want to say 352.8Khz? This frequency is not so rare,
is the one used for the DXD recording format:

HIGHRESAUDIO | Home of audiophile music


Fidelio Audio

hirez69

[qusp]

yeah thats what I meant correct. too many numbers bouncing around my head.

yeah but thats just a conversion to PCM from DSD, not a recording format, there are no ADCs other than the ESS one that will do such speeds afaik. most high rez recordings use the 24x multiples for 96kHz and 192kHz. You could use whatever was more important to you, you could have both XOs as 22.1 multiples ie 45.1584 and 90.3168. but for me I really only want 96/192/384 for hirez and the 45.1584 will cover everything up to 176.x for the 22.1.

edit: the page you linked shows only studio masters in wav at 352, or DSD, no DXD.

4 files on that page does not make it common ;p

[1audio]

Wave at 352 seems to be what DXD actually is. Digital eXtreme Definition - Wikipedia, the free encyclopedia

Hires files really exist at 96 (common) 176.4 (RR HRX and a few others meant for mastering for CD), 192 (nice big number so it must be good), DSD (mostly rips from SACD but a handful of actual released files exist). There are a handful of 2X or 5.6 MHz DSD files but they are not a real distribution format and make for gigantic files.

Supporting DSD would require a seperate path through the fifo for the extracted DSD data. if Ian could recognize the DSD flag (DoP) and pull the data inside the FPGA and route it to a separate set of outputs for DSD inputs on the DAC chips that support DSD this would be a leading edge device. That may be a pretty involved project. The clock rates are compatible with 176.4 KHz.

This is like a 78 RPM microgroove vinyl disk. I have one. Getting together a turntable to play it was a task that took some time. It did sound good, had about 8 minutes of music on each side and was clearly a dead end. If you want to make something that can play an odd format because it can you will have a feeling of accomplishment afterwards. But if you want music its a lot of struggle with no real reward at the end.

[MisterRogers]

+1 to a FIFO based I2S/DSD solution (bypass, DSD FIFO, etc.). Along with multi-channel support, we can keep Ian busy for the foreseeable future :-) It's funny how we all are; give us something that a year ago simply wasn't available, and even before using/deploying - we want more. I know I'm that way. So for all of us, I'll say it again Ian - THANK YOU! If/when you get to these other things, we'll be right there. But rest, pace yourself, enjoy life.

Re: XO group buy - if we can come to a consensus, I'm more than happy to organize and drive it. My needs are pretty simple: A quality pair of clocks that'll handle all frequencies up to and including 384mhz

[qusp]

Originally Posted by MisterRogers

+1 to a FIFO based I2S/DSD solution (bypass, DSD FIFO, etc.). Along with multi-channel support, we can keep Ian busy for the foreseeable future :-) It's funny how we all are; give us something that a year ago simply wasn't available, and even before using/deploying - we want more. I know I'm that way. So for all of us, I'll say it again Ian - THANK YOU! If/when you get to these other things, we'll be right there. But rest, pace yourself, enjoy life.

Re: XO group buy - if we can come to a consensus, I'm more than happy to organize and drive it. My needs are pretty simple: A quality pair of clocks that'll handle all frequencies up to and including 384mhz

weve just spent the last couple pages here and the GB thread discussing that this is impossible with current hardware no matter what clock you use unless its able to change frequency on the fly, so I would say your needs are not simple at all . funny thing is with the right output filter you kinda dont need the dac at all with DSD

thanks for the info on DXD Demian, still doesnt make it any more important to me as recordings in that format natively are VERY rare and I care not for nordic folk music so i've been watching from afar mostly, I dont care to pay more for upsampled or 'remastered' music.

I mainly use 96/192/384 for video and my own production needs, so I can playback tracks i'm working on for kicks and render analogue modeled synthesis more realistically

[MisterRogers]

Yea, my tongue was was firmly planted in my cheek with that comment :-) On point and of general interest in this topic; I posted a similar query (switching I2S/DSD) in the TP forum, and Russ responded with a top view of a mux/demux board designed for just that. He indicates that it'll be available very soon (emphasis mine).

Less on point, I've amassed quite a cache of dff/dsf SACD ISO rips of music I enjoy (Dire Straights, Steely Dan, Diana Krall, etc.) that sounds fantastic through my I2S/DSD multiplexed eXD board/BIII. Eliminating the PCM conversion is quite an improvement (IMO, subjectively, blah blah). Though...I'm always up for some stellar nordic folk music :-)

[1audio]

Probably the best value and almost the best you can get for less than $100 each are the Crystek CCH. A group buy won't save much over the single unit price at Digikey or Mouser. They do benefit from a really good power supply (see my circuit earlier in this thread that was triggered by remarks from Gordon Rankin about those oscillators). The synthesized clocks are better than I first thought but still not in the same class. I know of a better solution at $100 ea (min quantity of 10) and $500 plus per oscillator will get a 20 dB improvement but would require 2U of rack space to support. And probably not be audible.

[qusp]

Demian, you wouldnt happen to know at what point crystek will sell custom speed parts would you?

touche =) sorry misterogers: i'm used to that strange textual blindness here.
none of the artists you have named have released anything that could have been recorded in any of these formats. the best you could hope for is a reel to reel digital rip


edit re crystek: i'm going to email them about MOQ

the new CCHD-575 looks promising too. of course its got 'only' -90dB at 10hz which they term 'ultra-low phase noise' as well, but apparently this isnt good enough for feeding my chickens accurately each day … (Demian comment not aimed at you, just someone slagging the 570)

the 575 is marginally better than the 950 which I believe still is or at least was, the standard part on the buff II.

the 957 doesnt even seem to be available above 50MHz, rather than just not being a standard part like with the 950 and 575 but i've sent them an email anyway