Adat Master/slave issues

[pseudojazzer]

Hi Guys,
Just got my noah back on track, but got the old issue of crackles with the audio via ADAT.
In the past i solved this by putting scope as slave and noah as master - problem solved. However, my setup has changed since and i am now using a presonus Digimax FS as the master, and scope as slave. I've had no probs using the system like this - but in order to use the noah i have to turn off the presonus adat and use them both "standalone" - which is less than ideal!
The presonus has BNC in and out - and yesterday i bought a 75 ohm BNC to BNC cable - connected the presonus out to noah in, and tested the system - hoping that the clicks and crackles would go. Unfortuately not.
So the current configuation is presonus master (i would choose this as it is supposed to be a very good wordclock) and the scope and noah slave.
What am i doing wrong? any ideas as to how to sort this issue? do i need a zlink?
Any thoughts much appreciated.

Cheers,
Tom

[H-Rave]

the presonu digimax LT is a 8 channel mic preamp,what are you using it for exactly.

[pseudojazzer]

Hi H-Rave,
I'm using the presonus as my audio in frontend, I have mics, drums, guitar, bass etc going in through that.
In theory i could just put the audio out from the noah in there as well - however i want to go out via adat from the noah so i can get al the instruments recorded separately on different channels, which is what i was doing before when only the noah is plugged in. I would like to be able to do this as the same time as recording through the presonus adat as well...
Hope that answers your question.
Cheers,
Tom

[astroman]

you probably know Craig Anderton's Pro Review of the unit, otherwise there may be some hints - and for all others anyway...
it seems so be an amazing box, regarding quality, versatility and price

did you try terminated BNC connections as an alternative ?
actually I don't understand why precise instructions about this topic always lack - does it auto-terminate or not, where to apply etc.
Termination isn't self-explanatory and in cases like SCSI rather considered 'black magic'...

cheers, Tom

[valis]

Determining whether Noah is happy working as slave via bnc would be another troubleshooting step I'd take, using only the noah and the gear i wanted to slave it to.

Most gear is not auto-terminating (in the video world I would occasionally see self terminating stuff but can't say I've played with enough audio stuff to know if there is self termination in this realm). I have my RME connected to my Scope breakout sync without any termination, but generally speaking the RME is very forgiving and adjusts to this somewhat to insure a clean signal. 75ohm cables aren't even required as much anymore for short cable runs with RME and other modern manufacturers, since components are more tolerant and higher power these days. This makes us lazy and less aware of the issues...

Even with modern gear, when doing longer cable runs or when chaining multiple pieces of gear together termination may very well be more of an issue, even when using proper 75ohm cables. Also it's possible that working at higher samplerates (I work in 44.1) may cause more reflections back down the cable when unterminated, I'm not sure.

Also, now that my gear isn't 30 feet apart even ADAT sync seems 100% stable, and I could probably get by without relying on the bnc. Already I have 2 extra pieces of gear hanging off of the RME & Creamware respectively that are sync'd via bnc & spdif. No issues with the clock distribution here, but again it seems like Noah is your problematic link so I'd figure out what its happy with first.

Lastly, I'm not sure how much gear you have connected via that bnc but eventually simply daisy-chaining ceases to be an effective solution and you have to use a clock distributor. Probably not with only 3 pieces of gear though...

[pseudojazzer]

Thanks for the replys guys - was away in the country this weekend - nice to get some country air - and caught the orange lunar eclipse in a clear (non city) sky - which was a bonus!

Ok - so where to start - first Astroman - Great link, thanks.
I can vouch for the digimax FS so far - i've had it about 4/5 months, and havnt had any probs - except this one. The preamps are clean and its handy and small - with a much lower noise floor than i had before. I've been doing a few little short flim things just recently and hence working in 48 - syncing with scope and cubase is as easy as pressing one button.. the rest is automatic - beautiful!
Anyway - i connected the BNC pretty hastily and didnt turn the unit around - its in a shelving system and i just reached around to plug it in - so didnt see the BNC teminate button - and will try that later today - that could be the cure!!

Valis - the noah is happy when "standalone" with scope - as slave - there are no crackles - its when it is master that it crackles, or with the presonus as master.

I shall try the bnc terminate that both you and Astro mention - i'm such a dumbass for not seeing that in the first place - typically went and got the lead and just plugged it in blind without looking at the back of either unit...
manual? what manual? ..errr perhaps i should read it this time

Anyway - i'll post back if i get it to work.

Cheers,
Tom

[Shroomz~>]

Hi there,

try your current config at 44.1 & I bet it works. Don't ask me why, but the Noah isn't particularly happy with 48kHz operation. It works flawlessly at 44.1 though!!

cheers,
Shroomz

[kylie]

Termination isn't self-explanatory and in cases like SCSI rather considered 'black magic'...

SCSI is *NOT* magic. There are *fundamental technical reasons* why it is necessary to sacrifice a young goat to your SCSI chain now and then.

just found that and had to post it...

-greetings, markus-