i2s to eiaj convertor

[MortenT]

Is this latency problem an issue with a Mac setup as well?

[CKL]

Mac OS & Linux have a smaller latency then Windows as its kernel is better coded.

[fumbles]

As a reference, over 5 minutes on XP SP3, running email, 2 browsers, foobar pushing 16/44 S/PDIF using ASIO, I am showing peak 74us average around 30.
No WiFi though, Gig E/net.

[ole]

I assume you are talking about the latency of the LAN or WLAN connection.

It is normal that latency varies, and it is not a problem if it stays within limits. Those limits are solely determined by the amount of buffering in your playback software and varying latencies should not have any effect on sound quality. Using WLAN is almost always a bad idea, but not because of unpredictable latency. The transmitter simply pollutes the signals in the rest of the nearby circuit.

Ole

[fumbles]

No, this is a measurement of the latency of the Delayed Procedure Call queue, which will govern (amongst other things) the responsiveness and ability to sustain virtual real-time USB transfer of audio data.
Kernel level drivers executing wait states or other not-recommended cycle consuming procedures within a delayed procedure call routine (interrupt driven), will introduce excessive delays in the DPC queue and increase its latency.

Basically a measure of the responsiveness of the system (hardware & drivers) to interrupt driven requests.

[ole]

Ah, I see. But if it really gets that bad, there should audible dropouts, not just subtle degradation. At the DAC side, there should be some sort of buffer to compensate for that, no? I think that responsiveness / low latency is of little importance in this application, as long as the average data rate is correct. For mastering / recording it's of course a different issue.

Ole

[fumbles]

The latency issue was raised in the context of using the X2 to convert USB -> i2s to feed Yeo's "Black Crow" i2s -> EIAJ converter.  Whether it buffers the i2s output or not, the X2, from Tom's advice, requires a steady input of data to perform optimally - if I understand correctly this is due to its being an Isochronous device rather than an Asynchronous one.
Dropouts would indeed be the outcome.
Comment was made WRT latency spikes being caused by Wifi, I observed no issues on my machine w/o wifi.
Question was made WRT Mac - this discussion had been primarily Wincentric, nix systems handle such issues differently (and will usually claim better - they may well be right).

[CKL]

HiFace is famous because of using async. USB. 

[CoughinHK]

Hi,

AFAIK the X2 has a small buffer in the Tenor chip that it uses to hold a given amount of data sent over a given amount of time. From this it recovers a clock by some 'simple' maths. So if the data isn't sent on time every time the recovered clock is out which ultimately causes distortion.

I've actually heard music skip, speed up and slow down when streaming it over wifi because the PLL has been so messed up by wifi timing errors. It's an extreme example. With the X2 I've just heard a more muddled and duller sound because of timing errors when things weren't working well.

What I'd really like is a device like the QLS QA550; but one that can read through an isolated SATA interface so I can use an ssd or hybrid hdd.

cheers

[milen007]

hi guys

what sort of playback software that do 24 bit? itune?

do you guys use high resolution playback software such as amarra or pure music? are they good?

erwin

[ToniM]

Hi Yeo,

installed my Superclock 4 from Audiocom yesterday and hell a futher improvement. Do you think an Paul Hynes 3.3V reg for the dsp chip of the QA550 are benefitial? I will take this thing to the limit 

regards Tony

[Paul_Hynes]

Hi Toni,

Talk to Leo as he has already done this.

Regards
Paul

[milen007]

Thanks Yeo,
For the re-welcome

Yes, I'm interested in that script - I'll email, thank you.

Maybe you can post your impressions of the I2S Hiface when you get it & I can answer any questions here?

John

hi guys

i got the hiface today. wondering if any of you know how thing suppose to be connected? i am abit confuse. actual picture of them connected with each other is really great.

also how do you connect the black crow to the mojo 2?

thanks in adv
erwin

[jkenny]

Hi Erwin,
Hopefully I can sort it out with you via email?

John

[milen007]

Hi guys

Does the black crow need the MCLK feed?

Erwin