Oasys/EXB-DI sync/noise problem ... any thoughts ??

[Daz]

Hi All,

I am having some difficulties with the Oasys / EXB-DI when syncing the Oasys via Word Clock to my RME Fireface 800.

The Fireface is configured to be clock master and the sample rate is 48 kHz. The Oasys is configured to use Word Clock as the clock source in Global mode. The ADAT output of the EXB-DI is connected to the first ADAT input on the Fireface and Word Clock output of the Fireface is connected to the Word Clock input of the EXB-DI.

The Fireface SyncCheck mechanism is reporting that the ADAT connection from the O is synced to it's clock correctly and the Oasys is not reporting sync errors. However I am getting some fierce digital dropouts. If I play a song in sequencer mode I get clicks and pops appearing on all ADAT channels (not just 1/2 where I have routed the main outs).

I am using a kosher 75 Ohm BNC-BNC cable for the word clock connection and have tried connecting the cable directly from the Fireface to the EXB-DI and also with a T-piece/terminator on the EXB-DI end. Finally I tried a t-piece/terminator at both ends. There are no other word clock devices in the chain. I've tried different cables and my other Fireface. The T-pieces and terminators I am using are the correct pieces for the job (as recommend by the Apogee website). Additionally my equipment is connected to a Furman power conditioner, so hopefully the problem is not due to mains noise.

If I connect the Oasys S/PDIF input to the Fireface S/PDIF output and use that for clock instead of using Word Clock, I don't have the problem.

Any thoughts ? Thanks !!

Daz.

p.s. T-piece is Brit speak for what Americans call a T-adapter I believe.

[Daz]

If I connect the Oasys S/PDIF input to the Fireface S/PDIF output and use that for clock instead of using Word Clock, I don't have the problem.

Actually ... after further testing this doesn't work well either

I think I've now tried every possible combinations of optical and word clock cables ... so I don't think it's a cable issue.

Daz.

[Daz]

Presumably the EXB-DI word clock input is not internally terminated ... it's hi-z ? The documentation included is kinda light.

[MartinHines]

Check your PM.

[Vermeer]

Comon guys...

Share the solution with the rest of us. I own an Apogee Trak2 & I'm very interested in direct digital recording via ADAT and SPDIF.

[Daz]

No solution yet.

Another symptom ... I am in disk mode and I open a folder on a CD. As soon as the disk started spinning/seeking the ADAT output spat out such a blast of digital noise, I nearly jumped out of my skin.

When I sync the Fireface to the Oasys it seems to be okay. However I don't want my master clock to be something that behaves so poorly as a slave

FWIW this is nothing to do with buffer sizes or firewire bandwidth ... it happens even when the Fireface is running in standalone mode and the Mac host is turned off !

Right, what did I do with those 1/4" TRS cables ?

Daz.

[coucou]

HI there,



Have you found any difference in terms of sound quality when using the EXB-DI in SEQ mode or using the SPDIF out at 96k.

IMO the 96k SPDIF out sounds better although the manual says the internal functioning of the oasys is at 48k. In general to me the Oasys sounds better in PROGRAM mode than in SEQ mode. Do you feel the same?

Thanks!!
Rob

[przemm]

Hi Daz,

My Oasys doesn't want to synch at 48k by EXB-DI nor at 48k up by SPIDIF OUT - I got a Worclock error - I tried to synch it to TC Konnect Digital Konnekt and Eventide H8000FW and every time I have got lots of noise and dropouts. I have no problems with synching other devices using the same BNC cables. Probably there is something is wrong with the EXB-DI board. It is a pity because 8 digital channels out are so useful... But why wordclocking through SPIDIF OUT is not working on my O? No idea. You are right about analog cables - it is time to pull the snakes from the closet.

[Daz]

Hi ... some Oasys units have a problem syncing to external wordclock received on the BNC/Wordclock connector on the EXB-DI and need to have a hardware modification in order to work correctly.

See this old thread for example :

http://www.korgforums.com/forum/phpBB2/ ... hp?t=24901

It should sync to external wordclock received on the S/PDIF input without modification IIRC.

HTH,

Daz.

[przemm]

Hi Daz,

Thanks for the info - I'll investigate the issue with my Oasys.

Przemek

[MartinHines]

Hi Daz,

Thanks for the info - I'll investigate the issue with my Oasys.

Przemek

As Jerry K. from Korg USA mentions, the OASYS ADAT External Sync problem only relates to OASYS keyboards with the following Serial Number ranges:

-- OASYS 76: #1 -- 890
-- OASYS 88: #1 -- 1040

If you do have one of these units the repair (using the Korg "ADATMOD" kit, performed by a Korg Authorized Service Center) is free.

[RC-IA]

i'm about to buy the adat-DI. my oasys is 000061, so i should need the repair kit. what i want to do is to buy an adat sound card, why should i use external clock (and so, need repair kit)? or is it ok to use internal clock (and so i won't need the repair kit)? what the difference exactly, please. thanx

[TagPass]

i'm about to buy the adat-DI. my oasys is 000061, so i should need the repair kit. what i want to do is to buy an adat sound card, why should i use external clock (and so, need repair kit)? or is it ok to use internal clock (and so i won't need the repair kit)?

Since my tech never called me back, I decided to forgo the ADATMOD repair. I've been clocking my soundcard from the Oasys via the EXB-DI ADAT channels and it has been absolutely perfect. Maybe someday I'll get the repair done and hook up the wordclock -- perhaps when I find a tech I'm 100% sure of. In the meantime, it works fine and sounds perfect, so yes, you can certainly get by without the repair!

[RC-IA]

thanx tag. but if some people want to use the external clock it's maybe it's better or have some advantages, i really to know those? or the repair kit do not have to be

[MartinHines]

i'm about to buy the adat-DI. my oasys is 000061, so i should need the repair kit. what i want to do is to buy an adat sound card, why should i use external clock (and so, need repair kit)? or is it ok to use internal clock (and so i won't need the repair kit)? what the difference exactly, please. thanx

You might want to sync with an external clock if it is better than the OASYS digital clock or you need multiple clock outputs (i.e. you are syncing a large number of digital sources). For example, I suspect the Apogee Big Ben has a better (more precise) digital clock than the OASYS (it also allows video word clock sync and has 6 clock output ports):
http://www.sweetwater.com/store/detail/BigBen/

You only need the ADATMOD Kit repair if you sync with an external clock (and you have the EXB-DI installed). If you only sync using the OASYS clock you won't notice any problem.

As I posted in the other thread:

PROBLEM:
There is a known potential issue regarding digital noise (pops and clicks) involving the OASYS and the EXB-DI ADAT board, which ONLY occurs when ALL of the following conditions are met:
-- you have an early OASYS unit (low serial number, e.g. my OASYS 88 with Serial Number 00030)
-- you have the EXB-DI installed
-- you clock the OASYS from an external word clock source (if you use the internal OASYS digital clock you won't have a problem).

SOLUTION:
There is a formal "ADATMOD Service Kit" (parts and instructions) that can be installed by a Korg Authorized Service Technician. The repair primarily involves the replacement of a PCI card. The technician involved in my repair (I just had this done) said the repair is pretty straightforward. The hard part (and most of the time involved) was actually gaining access to the part of the OASYS where the repairs are made.