All I can say is UNF*CKIN'BELIEVABLE!!!

  • Thread starter Thread starter Blue Bear Sound
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Blue Bear Sound

Blue Bear Sound

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Midiman - Digipatch 12x6..........

Lightpipe and S/PDIF digital routing... works great -- UNTIL you find out that it only supports 16-bit, Type I ADAT Lightpipe I/O!!!!!!!!! That means I've got to redo all my recent backups (the backup ADAT was routing thru the PB) to avoid the butchering it does to my digital signal............ (it truncates above 16-bit)....

Nowhere does it say anything about it in the manual - I found out about it via R.A.P.

16-bit - give me a fuckin' break...... :rolleyes:


Sjoko/Skippy - I still need the digital routing --- any thoughts on the new Nuendo DD8 or the Z-Sys ADAT detangler?


...a very PO'd Bear

*grrr* :mad:
 
Oh, shit. Sorry, Bruce: I knew I should have posted that here.

I did quite a bit of research on detanglers a while back, and found out that *none* of them except the Z-sys Z8.8a will actually do >16bit lightpipe. Not the Fostex, not the Digipatch, *only* the Z-sys. All of them lie like dogs on their spec pages... except Fostex, who finally took any mention of ADAT _off_their page web page. Z-sys: http://www.z-sys.com/pp_detm.html#z8a

I decided at that time that I'd just wait and see: that market hasn't matured enough for me, and I can get to the back of my rack easily enough. I also have to have one that is sophisticated enough to take an unused port _dark_, not just put digital 0 on it (that's a requirement of the D1624, which disables its internal converters if there's sync present on the ADAT port). Anyway, I put those funds towards the purchase of my Ghost, which is now installed and is a very happy addition to the room...

Don't know anything about the Nuendo piece, other than the fact that Steinberg never build anything themselves- so it is a rebadged product OEM'ed from someone else. I'd bet that it's a Rosendahl piece, by the look of that faceplate...
 
The back of my rack is not really easily accessible -- all I really need to do is be able to connect fibre optic cable together - no conversion, no format switching - simple re-connecting to add or remove devices from the lightpipe I/O chain...

Is there such a thing as a connector that simply joins 2 male fibre optic ends together? A pair of those and I'd be set!

Bruce
 
Somebody (Hosa, I think) makes a TOSLINK manual patchbay: it's got a bunch of TOSLINK connectors on it, and you plug shorties from port to port. That'd _probably_ work for either of us, but I had serious concerns about how well it might work.

I probably worry too much, though. I didn't check into it any further than just noting that it existed... Although, now that I look at it, it _is_ powered, which means that it will regenerate data across the porst- and which could mean that it may _also_ truncate long words. Here's the web page: http://www.hosatech.com/product_page_patchbay.html#PBP-362

The product manual on that page doesn't lst _any_ word length specs, but it does list their phone number... Best ask Hosa on that one!
 
Actually, Hosa appears _not_ to suck on optical: they make a plastic-to-glass converter that's actually highly regarded for long-haul use. I'll have a look at that other thingus as time permits. It's not familiar to me, but I'm not surprised...

Sjoko, any pointers? I'm too new to this dadgum digital nonsense to be of any _real_ use...
 
Will the Fostex COP converter work ?..cheap ..I think light to spid in and out....Small box about $50.00..

Don
 
Sorry Don.... I'm looking for multiple lightpipe I/O with flexible routing, along with either multiple S/PDIF or AES/EBU I/O....

Basically the digital equivalent of an analog patchbay.... but of course, it needs to handle at least 20-bit.........

Bruce
 
Oh I thought you were just trying to jumper...Cool...Saw A dig patch...I will look and see if I find it,I will stick it up here if I do...Good luck

Don
 
The passive TOSLINK couplers? A stong "maybe". Each joint brings with it some loss: 2-3dB (in the baseband visible light spectrum- not the modulated audio spectrum), maybe. How much headroom do you have before you get to the point of inducing bit errors in the encoded data stream? Beats me. That optical stuff started happening after I stopped paying attention.

Point 1: the Fostex and Midiman products can't do ADAT because they are smacked right up against the bandwidth limit of their lightpipe _reciever_ hardware. That tells me that prosumer ADAT gear does not have much bandwidth to spare, *regardless* of what the data sheets (which I haven't looked at) say. Do you want to stuff 24bit data streams through that maybe-works, maybe-doesn't box?

Point 2: Digital data does not tolerate bit errors very well, unless there is significant overhead in error correction codes (Hamming, maybe, or Reed-Solomon) coming along for the ride. That leaves ADAT out.

Point 3: If you're using house clock, maybe it'll help some. If not, who knows?

Too many maybes. I have no good answer for you: I'm working solely on (obsolete) engineering guesses and educated gut-feels here. However, 24/48k ADAT appears to run the lightpipe hardware right up against the stops. You might well be able to make passive couplers work, but it gives me heartburn: I'd rather use active couplers (with gain in the optical domain, and ideally reclocking of the signal as well), or none at all, and hope to stay away from the corner of the envelope where bit errors start to crop up. I've heard crunchies, and I do not like them.

If you opt for the passive couplers, use _only_ really good optical cables, and keep the fingerprint oils off the cleave planes (at the interface: where one fiber ends, and the next begins). Use some Freon TF to clean them, each repatch.

The final chapter in this one is not written yet. I need to go read some data sheets and AES articles, and find out what the actual transmitted noise margin really _is_ over your average TOSLINK tx/rx pair. I never had to give a shit until now: to me, lightpipe hardware was always solid like a potato (since I awoke from my sleep, anyway).

This gotcha stuff is happening more often. Ultimately, all this modern hardware has to obey the same old laws: if there's more noise than signal, you're _fucked_. Hey, Sjoko? Help me out here. What does _current_ engineering practice say?
 
This reminds me of the problem I had when my Masterlink and my Tascam DA-40 DAT wouldn't talk to each other digitally.... no reason for it - both handle S/PDif and AES/EBU, but the "standard" protocol was implemented differently in each one! I had to use a Midiman CO3 in between 'em so that they'd play nicely together... go figure.... I called Tascam - they blamed Alesis for being non-standard... I called Alesis, they said Tascam's fucking up.... :eek:

Yikes...

I was fucked by that one too!!!

Thanks for the words Skip!

Bruce
 
Hope this helps... if not I tryed..Says that it will handle 20...Good Luck

Z Systems Detangler...Couldn't get the link to work


[www.z-sys.com]
Don
 
Yeah -- 2 real options - the ZSys detangler and the Nuendo DD8... both are like $2K solutions though.......... :(

Bruce
 
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