longest good TDIF cable length?

[TotalSonic]

I use a Apogee/Soundscape IO896 which has 8 channels AES/ADAT/analog i/o that sends to and from one of my DAW's Sydec Mixtreme 192 soundcard via a single TDIF connection.

I've been using a 15' Tascam cable for a while for this without any problems - but recently I've been wanting to extend this a bit as I keep my DAW's in a closet and want to reposition my IO896 so that it doesn't have to be kept half way between the rest of my racks and the DAW.

The longest pre-fabbed TDIF cable I've been able to find is a 30 foot from Radial Engineering - http://www.fullcompass.com/product/259812.html

Seems it uses 110ohm Mogami cable.

So - showing my ignorance here - but is a TDIF connection a balanced connection similar to AES or is it unbalanced similar to SPDIF?

Any reason anyone can think of that there's reason that there would be any degradation from increasing length from 15' to 30' for this connection?

Seems from searching on the Sydec site that the TDIF spec states 15 meters as max length - so figure at under 10 meters I should still be ok - but then I saw some posts from a couple people stating they had problems with lock to signal at 25 foot lengths. Longest cable Tascam ever made themselves was 3 meters.

Anyone here have direct experiences with long TDIF cable lengths?

Best regards,
Steve Berson

[CurtZHP]

If you look at page 2-22 of the manual for the Mixtreme card, it gives the pinout for a TDIF cable. From the looks of it, I'd say the signals actually carrying digital audio are unbalanced, since there's only one for each channel pair in each direction (with common grounds provided elsewhere).

[TotalSonic]

If you look at page 2-22 of the manual for the Mixtreme card, it gives the pinout for a TDIF cable. From the looks of it, I'd say the signals actually carrying digital audio are unbalanced, since there's only one for each channel pair in each direction (with common grounds provided elsewhere).

Curt -
Thanks - and from the pinout definitely looks like your correct and that it's definitely an unbalanced connection. 30 feet might be pushing it - but maybe it will be a non-issue. I'm not sure I want to spend $186 for a cable to find out that there's increased jitter or clock lock issues from using it - but I'd really like to have the increased cable length! - so I'm not sure how to proceed with this.

Best regards,
Steve Berson

[sebastiandybing]

You could buy tascams tdif to aes converter, http://www.sawstudiouser.com/forums/showthread.php?t=6940

Maybe David still have it ?

Sebastian

[Perry]

I seem to recall asking Dirk at Sydec about this quite some time back, because I was considering something like this as well. I think I was wanting apx. 25 ft lengths iirc. As it is the longest I've used was apx 16 ft. (with no known issues).

Unfortunately I don't recall what Dirk's reply was... and I ended up not following through with this plan and redid my room a different way that made it unnecessary to have the extra lengths.. but... it does seem that the TDIF was going to be a problem.

I'd suggest writing Dirk a "Help Me!' note and get it straight from the horse's mouth, so to speak. :)

Perry

[TotalSonic]

Sebastian -
thanks for your suggestion but I already own a Sydec iBox AES-4. The Apogee/Soundscape IO896 actually is even better in that it does 8 channels of AES i/o instead of just 4, and it has much better clocking at the 2xFs rates than the iBox AES-4 ime also. The issue in positioning my box (in the same position as my Sydec iBox AES-4 used to be) isn't the available length for the AES connections that go from my Z-sys patch bay - but in the available length from TDIF to DAW (which is kept in a closet at a distance from gear racks).

Perry -
Doing a more thorough search than I had before of the Sydec board on cable length came up with a few posters who stated they had problems with sync when using the 2xFs sample rates when using longer lengths - so since this is for my mastering rig where I simply don't want to do anything that risks signal degradation - I've decided to save myself the cash, keep the cable length shorter, and just leave the converter box where it is (which is somewhat inconveniently away from arms reach if I ever want to change clock controls or engage the soft limit - but guess I don't really change these things so often that having to get out of my chair ).

Thanks for the responses!

Best regards,
Steve Berson

[sebastiandybing]

thanks for your suggestion but I already own a Sydec iBox AES-4. The Apogee/Soundscape IO896 actually is even better in that it does 8 channels of AES i/o instead of just 4, and it has much better clocking at the 2xFs rates than the iBox AES-4 ime also. The issue in positioning my box (in the same position as my Sydec iBox AES-4 used to be) isn't the available length for the AES connections that go from my Z-sys patch bay - but in the available length from TDIF to DAW (which is kept in a closet at a distance from gear racks).

Then get a AES4 box more and hide them in the closet together with the computer and use aes/ebu between the closet and the control rack:D

Sebastian

[Naturally Digital]

Perry -
Doing a more thorough search than I had before of the Sydec board on cable length came up with a few posters who stated they had problems with sync when using the 2xFs sample rates when using longer lengths - so since this is for my mastering rig where I simply don't want to do anything that risks signal degradation - I've decided to save myself the cash, keep the cable length shorter, and just leave the converter box where it is (which is somewhat inconveniently away from arms reach if I ever want to change clock controls or engage the soft limit - but guess I don't really change these things so often that having to get out of my chair ).Steve,
I have a custom made 25' TDIF cable I'm not really using at this point. I've never had problems with it at up to 48K but I've never used it at 2xFS. If you want to try this out, let me know and I'll ship it to you. If it works for you you can decide whether to keep it or not. It isn't fancy branded cable but it has metal hoods on the connectors. We could work out a trade for a 15' cable since I do need TDIF once in a while (just not 25' anymore). Anyway, let me know.

[TotalSonic]

Steve,
I have a custom made 25' TDIF cable I'm not really using at this point. I've never had problems with it at up to 48K but I've never used it at 2xFS. If you want to try this out, let me know and I'll ship it to you. If it works for you you can decide whether to keep it or not. It isn't fancy branded cable but it has metal hoods on the connectors. We could work out a trade for a 15' cable since I do need TDIF once in a while (just not 25' anymore). Anyway, let me know.

David -
That's a very generous offer! I'll contact you directly via PM - although I don't know whether I want to get rid of my 15' Tascam TDIF cable as I like having backups around - so I'd probably rather just make a cash purchase.

Best regards,
Steve Berson

[Naturally Digital]

although I don't know whether I want to get rid of my 15' Tascam TDIF cable as I like having backups around - so I'd probably rather just make a cash purchase.OK. That's fine too.