D25 to D25 Digital Cables

[Howdy Doody Time]

I replaced my radar II with a radar studio and I want to use the d25-d25 cables (3 of them) on the new machine.

however the cables were connected to T-DIF on the radar II (with a UFC-24 on the other end) and my new radar has an AES card instead of T-DIF - Which can also connect the radar with the UFC-24.

Will the cables be OK - or is the wiring completely different and I will damage my new radar?

Cheers.

[Hugh Robjohns]

I'm afraid those old TDIF cables are completely useless to you now. The (obsolete) TDIF wiring is completely different from the current AES59 format -- and the signals being carried are entirely different too. There is no compatibility whatsoever.

The AES59/Tascam, wiring arrangement is this:

This carries the digital signals in a balanced format with embedded clocking data in form of 'manchester coding'

Where as the obsolete TDIF wiring is this:

With unbalanced digital signals, separate clocking signals, and additional data flagging.

H

[Drew Stephenson]

Dumb question: why isn't the cable irrelevant here?
I'd have thought that it's just a series of pin-to-pin connections tied together. I'd have assumed that as long as the output and input were the same format then the cable would just be a conduit. What am I missing? (Sufficient coffee may be the answer.)

[Wonks]

I think the lines around the collections of pins indicate screening between pairs of trios of individual cables. So you'd be putting the wrong cables together within screens.

[Hugh Robjohns]

I'd have assumed that as long as the output and input were the same format then the cable would just be a conduit. What am I missing?

It's not just 25 identical wires between the two plugs.

AES59 requires screened pairs for the digital audio whereas the TDIF cable used screened singles. Also, different pins are allocated to the cable screen connections, and -- most importantly -- the inputs and outputs are on different pins so the cross-overs within the cable are different.

H

[Howdy Doody Time]

"I'm afraid those old TDIF cables are completely useless to you now. The (obsolete) TDIF wiring is completely different from the current AES59 format -- and the signals being carried are entirely different too. There is no compatibility whatsoever"

Thanks for that - very useful. I'm pretty sure iZ will have moved with the times and designed their card to comply with the AES59 Standard. I was going to simply dismantle the Radar II as some of the bits are compatible with the latest version, and I am a bit of a spares freak. Now however, I will keep it intact I think. It's still fully functional - I replaced the floppy drive and the internal C: Drive with solid state versions. The recording drive (a single SCSI) proved too much for me though, and it remains a spinning thing.

Thanks again.

[Drew Stephenson]

I think the lines around the collections of pins indicate screening between pairs of trios of individual cables. So you'd be putting the wrong cables together within screens.

It's not just 25 identical wires between the two plugs.
AES59 requires screened pairs for the digital audio whereas the TDIF cable used screened singles. Also, different pins are allocated to the cable screen connections, and -- most importantly -- the inputs and outputs are on different pins so the cross-overs within the cable are different.
H

Ah, I hadn't considered internal screening. And I certainly hadn't thought about different inputs and outputs. Presumably this makes these cables 'directional'?

[Howdy Doody Time]

Oh dear! I've just realised it's not just the cables that are obsolete. My UFC-24's (both of them) are no good for AES now that the format on the other end is updated. I mean who is going to make AES cables with the original T-DIF format at one end and the new format at the other end? I had hoped to avoid the expense of an ADAT card specific to radar but that would seem to be a forlorn hope if I want to continue with the UFC's. Bother!

[Hugh Robjohns]

I'm a bit confused... What are you trying to connect to the Radar Studio?

Presumably you used the UFC to convert from TDIF to something else for your previous Radar II? ADAT?

[James Perrett]

According to the Otari website, AES was an optional extra on the UFC24 so does your unit have the AES option fitted?

[Howdy Doody Time]

According to the Otari website, AES was an optional extra on the UFC24 so does your unit have the AES option fitted?

Yes it does (one of them does) I bought it new on Ebay and fitted it, a little bit tricky to fit but not difficult.

The other one has the standard 8 channels of AES in and out.

I just emailed iZ to check with them because they make the UFC's as well, and it might not have been wise to isolate a lot of users, so maybe they didn't update the format.

We shall see.

[Howdy Doody Time]

I'm a bit confused... What are you trying to connect to the Radar Studio?

Presumably you used the UFC to convert from TDIF to something else for your previous Radar II? ADAT?

I'm trying to connect a UFC-24 to my radar because any digital signal presented to the UFC is available on all other digital format outputs. This means I can send AES from radar to my digital mixing desks, via 24 channels of ADAT from the UFC.

I used the UFC to convert from TDIF to ADAT for my radar II as you say. My radar studio doesn't have the TDIF card, it has AES. I could have chosen a TDIF card when I ordered it, but I'd just bought a full AES card for the UFC so I chose the AES. I could also have bought an ADAT card for the studio and avoided the UFC but I didn't, - I liked my setup as it was.

I'm not surprised I confused you - I never can state the facts very clearly

[Howdy Doody Time]

Got a reply from iZ. Same as Dr Robjohns. Can't use the cables. No surprise there then. UFC-24 is still in business though, if one sticks to ADAT, or T-DIF, or SDIF2 or PD (whatever PD is) so the cables can go back onto the Radar II. Maybe I'll use it as a project machine, and persevere with trying to get hold of a SCSI to SATA bridge that actually works.

The Radar Studio uses SSD SATA exclusively, the bare bones Windows environment is isolated completely from the Radar files with its own SATA SSD Win Drive. One installs Nuendo onto that, and a special version of ASIO lets Nuendo speak directly to the converters. The recording SSD's have to be fast or the system rejects them. Popping the recording SSD's in and out is easy peasy because there are 4 slim caddies on the front Panel.

I haven't recorded anyone in over 8 years, but I think I will start doing that again.

[James Perrett]

I just emailed iZ to check with them because they make the UFC's as well, and it might not have been wise to isolate a lot of users, so maybe they didn't update the format.

I can't find any UFC documentation online but it should simply be a case of looking at the AES pinouts for each unit, seeing if they match up and then buying/building the right cables. Your old TDIF cables may work if they both use the same AES pinouts but the grounding and screening arrangements won't be optimal which will mean that any electrical interference is more likely to corrupt the data.

[Hugh Robjohns]

Got a reply from iZ. Same as Dr Robjohns. Can't use the cables.

Phew! Got another one right...

UFC-24 is still in business though, if one sticks to ADAT, or T-DIF, or SDIF2 or PD (whatever PD is)...

PD is short for ProDigi -- another obsolete bespoke digital connection format from the 90s, used on Mitsubishi's early multitrack and stereo digital tape recorders. The data format is similar to SDIF, but different enough to be incompatible, of course. It used 50-pin D-sub connectors for the 32-track machine (Called Dub-A and Dub-B ), and 25-pin connectors for the stereo machine (called Dub-C), all using separate pins for each audio channel, and a separate word clock etc.

So on that interface, only ADAT and the optional AES3 are still currently viable interfaces... How time flies!

Incidentally, the original Mitsibushi stereo machine from the early 1980s, the X80, operated with a 50.4kHz sample rate. All the subsequent PD machines adopted the standard rates. The multitrack x8xx machines were basically modified Otari MTR90s transports, and the format was unusual in having 32 tracks on 1-inch tape.

At the same time, Sony's first DASH machines only had 24 tracks -- same as analogue multitrack machines -- so Sony made sure their their second generation DASH machines could provide more tracks and went up to 48 tracks!

H

[Martin Walker]

Got a reply from iZ. Same as Dr Robjohns. Can't use the cables.

Phew! Got another one right...

You've got a lot to live up to now Doctor Robjohns - so we'll all be plying you with questions to keep you on your toes

Martin

[Howdy Doody Time]

I love this hobby always interesting, nearly always frustrating and always challenging. I'm sitting here with the latest radar, and all I can think about is replacing the SCSI in the ancient Otari version. The SCSI is new and quiet, but that's not the point, well it is the point, but it's not the point.

By the way, I have much more recent interfaces that are completely obsolete, remember firewire? I look at my Otari Radar II which is over twenty years old, and is very much alive and kicking and I know the mechanical parts will wear out long before the thing falls victim to obsolescence. The new version offers even more longevity having solid state drives and your DAW of choice having direct access to the converters. These things are not reliant on the whims of the computer - they are the computer.