Thanks very much for your response. I have a clock cable properly connected and tally lights indicate it works. TDIF remains a mystery. When I bought the TM-D8000 I didn't know TDIF existed or that I'd need TDIF cables to use the unit. I did due diligence and discovered that they are out of production and very expensive, which the previous owner didn't tell me. When all is said and done and misleading ads are weeded out, the cheapest TDIF cable over 3 feet costs about $170.
I immediately called MOTU tech support and asked them what TDIF cables were, why they were so expensive, and whether I could simply make some. Believe it or not, nobody I spoke to at MOTU could answer any of those questions; they wound up telling me TDIF cables were "special". When asked why they were special, there was a lot of chatter among themselves at the other end of the line, and then the person I was talking with said what amounted to "because they're special". They promised to call back with more details and never did.
Tascam never responded at all.
I noticed Sweetwater has a "Call us with any questions!" banner, so I did; after a lot of hemming and hawing, the tech I spoke to there said TDIF cables were "special". When I asked for more details, he gave me a two-minute speech that added up to "They're so special".
Online, at first I found plenty of TDIF socket pinout diagrams but nothing on how the cables themselves connect or what they're made of. I enlisted the help of someone I know to be a google search expert, who stumbled across an ad for B&H selling 3-foot TDIF cables for $35 or so. 3 feet is too short to reach the MOTU if it's mounted in the rack, but my theory is that if I set the MOTU down temporarily next to the TM-D8000 and have one working cable, simply evidence that the system can work at all, then I have a standard against which to judge subsequent hacks; so I bought one online.
Three days later I got email from B&H explaining that the listing was a mistake, the cables were out of stock and discontinued, and would I like a nice microphone stand instead.
Eventually we stumbled on
http://groupdiy.com/index.php?topic=417.0 which is the only thing we found with any clear information at all. I have no way of determining its accuracy because we found nothing to compare it with. The person posting says that TDIF cables are essentially null cables and thus have all pins reversed end-to-end, the "specialness" being that each of 8 signals is carried in a mini-coax with individual ground points for each shield. The article says you accomplish this by "bursting open" 2 VGA cables and harvesting the mini-coax cables inside.
I immediately ordered 2 VGA cables, waited 5 days for shipping, opened them up and found no mini-coax inside.
At this point approximately 3 weeks have passed, the Tascam and MOTU are still not communicating and all I've managed to find out about TDIF cables comes from a single post I found on the notoriously unreliable Internet. At this point I am desperately perusing that single post with the laser-sharp heightened attention of a Critical Theory freshman practicing close reading. I'm like a prisoner in solitary with a life sentence and just one page of typescript.
How hard can it be? Ten lousy feet of copper wire with some kind of secret sauce?
Should I jump in my car and drive 400 miles to Montebello and stand in Tascam's doorway and just keep screaming until someone finally tells me the deep dark secret of what the hell is really going on? Or until the cops show up, whichever occurs first?
Or (shudder)...do I just lift the hood on the TM-D8000 and solder a fat handful of coax onto the analog points of each buss and add some buffer amps and make my own analog snake to plug directly into the MOTU and bypass the whole TDIF madness? Is it worth it? To never again have to have a freaking MIT graduate in freaking Cambridge, Massachusetts tell me a freaking bunch of electrical wire with a DB25 plug on each end is "special"?
No wonder everybody went over to optical.
As I prepare to give up and send the TM-D8000 to the place broken monitors and dead crabs go, I see that that single post *may* be claiming, or indirectly alluding to, that you don't really need mini-coax for short runs, which may or may not mean anything under 20 feet. It then says to make a null adapter out of 2 DB25 connectors soldered back to back.
I buy a 10 foot straight-through DB25 cable, solder up the adapter, plug them together and connect the whole thing between the TM-D8000 and the MOTU, and nothing happens.
That is where I am at this point. 3 weeks, about $75 in parts and countless hours of my and other people's time, and I still have 2 pieces of bulky expensive studio equipment that power up and self-test and display acres of lovely tally lights, and, unless you want to do nothing but analog 2-track with your 48 faders, without TDIF cables they are nothing more than boat anchors.
Anything you can think of, anything at all, would be appreciated, before I take an ax to this lovely piece of digital technology.
Thanks for sticking with this.
I think I paid $10 a piece for the 25 footers I gave away and $10 a piece for 6 footers a couple years ago.
