IS this JITTER??

  • Thread starter Thread starter johnfindlay
  • Start date Start date
J

johnfindlay

New member
Hi-trying to transfer 8 tracks at a time from a Fostex LV24 via ADAT litepipe
into an Ark 24 sound card to mix in logic audio.
On the play back in Logic I notice the snare in particular has a gurrgly-vibrato
kinda of tail -otherwise its all working...

do I need to send word clock into my Ark24 from the Fostex?

is it jitter?
 
Jitter is not supposed to be a factor on file transfers like that. Perhaps some other problems are coming into play? Is the receiving Ark24 card's clock set to the 'ADAT' digi input port?
Does the ARK have any signal quality indicators that would indicate clock errors? (Comparing to my Dakota here as a reference. :D
Wayne
 
Thanx-
ya everything indicates OK-no errors.
Im at 24bit 48K-

so i may not need a wordclock cable?-would it hurt to try?

JF
 
Interesting. You should get good clock from the input. Usually you'd get clicks if that wasn't solid. But a bit of coax would be a good pretty cheap test. :D
Wayne
ps Fostex is set 'master (or internal), card is set to digi input?
Just checking. :rolleyes:
 
ya-Fostex set to master.
You know Ive encountered that warbly sound before...

thanx again.

JF
 
mixsit said:
Jitter is not supposed to be a factor on file transfers like that.
Click to expand...

Not from what I heard especiallly with Adat. Its the most susceptible of the digital transfers to jitter, cable length, etc.
 
hey Mixit.....

Awsome thread on clocking etc..-only just browsed it----


Just got off the phone with a FOSTEX tech in Canada here-
he says you cannot get true phaze lock on a PC
when dumping over 8 tracks at a time via litepipe-he says its
because of inconsistencies in [a] the PC!

wow-I just spent alotta doe on rentals for the session -now
I cant get it onto into Logic to mix!?? How will I mix it -Ive no outboard gear!
I think i can run my FX from Logic back in thru a Mackie--but all in all
not much fun! [Probably sound bigger tho]

Im stunned... I cant believe its that hard to get phaze lock etc...

JF
 
Ummm, that doesnt make sense to me. I think they are feeding you full of shit. I send 24 channels of optical from my Alesis HD24 to my Motu 2408mk3 without any phase issues.

It doesnt sound like a clock issue either. Is it actually recorded like that or is it just doing that on playback. Im just wondering if its a monitoring or looping problem. The loop could have a delay on it that could cause a sound like that.

But its really hard to say without being there myself.

Danny
 
Thanx Dan-
ya... I dont get what the tech said at all.....
and he really overhyped the Fostex over Tascam & the HD24 too.

Remember what i have to do is 8 tracks "at a time" as my Ardvark Ark 24
has only on ADAT port-so- Im using MTC from the Fostex
to drive Logic Audio.
Well any i get alotta drift.

the tech also said it "may" help to use a word clock cable too...
[that was mentioned in that thread over at the Cubase forum].


JF
 
I don't know how much help this we be but if you're up for it.. :D I'm with Darnold (as well as being darn old myself. :p ) Dumping from ADAT's used to be the norm around here (and I have Fostex decks no less). What a crock. :D
Is the one track the only problem? Just to eliminate the really obvious, I assume you have heard the track(s) play from the Fostex analog I/O and they're ok there?
How about another test. Jump the lightpipe from the existing 8-out set into the next input over, record digi-direct back into fresh Fostex tracks, check them again analog out. This would get rid of questions about; clock, and ARK/daw issues, and might point to a bad output or light cable if it still fails.
Second option -can the Fostex do an internal bounce?
Last option -dump them to the Ark analog. Yeah, fine for a test, but you should not be having to go through all this...stuff. :eek:
Let us know how it goes ok?
Wayne
 
johnfindlay said:
...Remember what i have to do is 8 tracks "at a time" as my Ardvark Ark 24
has only on ADAT port-so- Im using MTC from the Fostex
to drive Logic Audio.
Well any i get alotta drift.JF
Click to expand...
Woaha! Bingo. Midi time code is dodo. +/- ten to 15ms at best. You're chasing the fostex?
I suppose it can be done, don't know, never needed it. I assume then you have to do more than eight tracks or you wouldn't be doing that in the first place.
Plan B. Arm a single track in each of the sets of eight (at the end of the songs is fine if you don't want to risk messing with the head), record a spike to all three (at the same time obviously). Loose the MTC, dump them in eight at a time and slide them around to alignment.
End of problem. ;)
 
The old clap -one beep trick -ya -its gonna be that i think for sure.

I havent used MTC for years - but i thought it was OK back then.

Thanks again.

JF
 
You know what's funny? I learned this several years ago from...Fostex (and Frontier) trying this exact same thing with my fostex decks, but it was with the adat sync cable. Even adat sync goes through mtc at some point in pc land. Did the bounce/alignment tests, bla, bla, bla. They never landed in the same place twice (for me. :rolleyes:
With the mtc slop, it may be the best you can hope for is to use it for song position at the head, then free-wheel from there. (Not sure here.) But WC must rule of all bets are off. (I think.
Pretty sure. :D :D
 
Funny im not old at all. Darnold is a nick name givin to me in my junior high years. Came from my name, Danny Arnold. Its pretty much stuck with me since i can even remember and people still think my real name is Darnold. My Nephews call me Uncle Darnold even. Its even funnier when i meet new people who learn my name as Darnold and then find out my last name is Arnold. They are so confused when they think my name is Darnold Arnold.

:D

Guess that was really unrelated, but i thought some understanding was in place.

But when i first got my HD24 and started using optical, i thought i was having syncing problems too. After trying word clock, midi, ADAT Sync, er every one i just had i figured out the clicks and pops i was getting was actually recorded into the audio and i just couldnt hear it before with my older converters and lesser sync clock. Guess im just saying this to give you the idea to not get caught up in an out of sync or phasing problem but something completely unrelated.

Maybe you can post an example of what its actually sounding like? Might give us a better idea on what your hearing.

Danny
 
Hey Darnold- my sessions today-then i figure out the transfer tomeorrow-uughh-
I will post a clip of some stuff-if youd be so kind as to listen.

thanx
jf
 
Alright cool, post it up and i will take a listen and see if i can help further determine whats going on.

Danny
 
I just would love to know the qualifications of everyone who are dismissing the professionals on this subject?

Would you of called Einstein a crack pot when he was telling you about nuclear fission?
 
I don't know Logics sync options but...

With a digital connection, and the audio interface is running on the external ADAT clock, then Logic needs to be running on the same clock as whatever is supplying that clock. So, in that circumstance, they already are in sync. All MTC needs to provide is start/stop and position etc.

Sonar has a sync option "Trigger and Freewheel". With this active, it does what I've just described, provided Sonar is set up to use the soundcard clock and the same card is its record or playback timing master.
The result of this system is a flawless transfer, as the pc is not attempting to re-sync/re-sample to chase the time code. Under "freewheel" and the interface on external clock, its already working to the external machines timing clock.

If you can't persuade Logic to use the soundcard clock as its timing reference, perhaps you can run the Fostex off the interfaces word clock (yeh, I don't know the Fostex either).
 
You must log in or register to reply here.
Back
Top