Digital Audio Glitching

andrew · Post by **andrew** » Tue Apr 20, 2004 3:18 pm

hey guys -

originally had this post in the xtc mode forum, but i've isolated xtc out of my problem,
so I've reworded it and here it is : I've also just read Jngaelin's post about glitching and seen the
comment about not using a pci graphics card, which my desktop daw has...

before i go on , my daw is :
a p3 , 1.7 ghz, with 1 gb of ram, and am running the scope version 3.1 on a power pulsar

post follows..

I've bought a new laptop recently(3ghz, 1gb ram) and a nice (latency of 6ms) fast sound card for it -
I wanna connect this beast up to my desktop which is running win xp, power pulsar via spdif

problem is i'm getting the glitching on the digital audio playing on the desktop coming thru from the laptop...

after further mucking about i'm sure it's the creamware digital audio that's
causing the glitching and that it's not a problem with the digital out on my
laptop sound card ( a firewire audiophille)

- I routed the spdif out of the audiophile back into it's spdif input,
played some sounds in logic on the laptop while recording only the
spdif input from the audiophille in soundforge. when i played back that recorded
audio it was clean - ie there is no glitching inside my laptops
digital system. thus i'm sure my post is one for this forum and not the m-audio one

any ideas... i should probs start by getting a new graphics card, me thinks, also - the motherbd in
my desktop is a micro atx - I've heard these are bad for graphics apps, but
nothing about the audio side .. any thoughts?

thanks in advance

Andrew

alfonso · Post by **alfonso** » Tue Apr 20, 2004 3:53 pm

You did set one system as clock master and the other as slave right?

arela · Post by **arela** » Tue Apr 20, 2004 4:05 pm

could be PCI bus latency timer problem.
graph card is likely to have some priority settings.

found some tips (general)here:
http://www.cakewalk.com/forum/tm.asp?m= ... Cglitching

a lot of reading, but....

astroman · Post by **astroman** » Tue Apr 20, 2004 4:33 pm

as Alfonso wrote you have to set Pulsar as slave to the Audiophile, unless that card has a special bidirectional sync mode (as some fx units have).
In that case you'd have to connect both s/pdif ins and outs, but that's not very likely.
I don't think that the 'load' of a single stereo channel is big enough to disturb the P3.
cheers, Tom

andrew · Post by **andrew** » Tue Apr 20, 2004 5:01 pm

re the wordclock master / slave thing - i was doing this in logic, as i said in the other post (will paste below) and was still getting the problem, (actually that's where i first noticed the problem)

the thing is, i've got other annoying issues on the desktop that lead me to think that there's something amis. was gonna ignore it and get on and write another tune, but now i feel like i'm on the path to fixing it i will keep going and sort it out (does anyone else get this ?)

problems with cw include :

when i've got any cw instrument playing (in xtc mode, that's how i like to work) inside logic, if i select another track sometimes i get crackling and glitching coming from the intrument, othertimes it will play out of time...

I also (had) a random reboot issue, which, as i haven't got round to fixing...

here's the orig post from the xtc forum :

any thoughts or help gratefully appreciated

cheers

Andrew

**************************************

hey dudes -

I've bought a whizz bang laptop recently and a nice (latency of 6ms) fast sound card for it - I wanna connect this beast up to my desktop which is running win xp, power pulsar..

When running logic 5.5.1 on both, I'm sending digital audio into the pulsar's spdif input, using the desktop as wordclock master, then on a spare audio channel in logic i'm selecting input's 3&4 (1&2 are the analog) and hitting the red rec button to start monitoring..

It's all good for a little while - i can hear what my laptop is playing perfectly, then after a couple of bars i start to get an annoying crackle coming through with the sounds... i'm checking the actual audio being output by the laptop and it's perfectly clear, and nothing is peaking- it's the digital path that's cacking it up. I've tried lots of different recording options in logic on the desktop and no dfference, altho i just realized i could try sound forge on the desktop receiving the digital audio, to isolate whether it is the desktops logic instance, or the actual digital cable / connection on the pulsar thats at fault.. I'll check when i get home from werk, and post again...

nyway - has anyone had any similar issues? Are there any faq's or tutes about?

Thanks guys

Andrew
http://www.organicrecords.net

astroman · Post by **astroman** » Tue Apr 20, 2004 6:00 pm

On 2004-04-20 18:01, mrbiscuit wrote:
re the wordclock master / slave thing - i was doing this in logic,
...
It's all good for a little while - i can hear what my laptop is playing perfectly, then after a couple of bars i start to get an annoying crackle coming through with the sounds...

Alfonso and me were writing about the setting in the SFP samplerate dialog - Logic cannot do this, that's a hardware thing

On the other hand your description reads more like a buffer runs mad.
It works for some time until the buffer is played through and then the traffic gets stuck.
I don't use Logic so I'm no expert, but to me it seems the software monitoring disturbs the recording process.

just 2 cents, Tom

andrew · Post by **andrew** » Wed Apr 21, 2004 2:46 pm

>Alfonso and me were writing about the >setting in the SFP samplerate dialog - Logic >cannot do this, that's a hardware thing

hey - right that sounds interesting...

yeah - as i said the problem happens in logic and when monitoring the digital signal in SFP. I'll try the sample rate dialog in SFP

- on the bright side, i discovered that i do have an AGP graphics card this evening

My pc didn't come with any spec so i've had to do a lot of mucking about to find out what graffix card is ... no info in display settings properties - actually most machines, even if they are aGP seem to say pci in display props, settings, advanced, adapter, properties... so that threw me for a while..

Andrew

****************

andrew · Post by **andrew** » Wed Apr 21, 2004 5:36 pm

hey guys - great news, thanks for your help, set the desktop pc as wordclock slave and it's working beautifully... in SFP mode and also in Logic 5.5.1. now i've just gotta sort a few more issues with CW and my DAW will be working at full power...!!!!

cheers guys

Andrew