DMA8+ to Odyssey DI6-3 DB25 pinouts

[Leo Enticknap]

I need to hook the analog output of a DMA8+ to the input of an Odyssey DI6-3 (5.1 to 2.0 downmixer for drive-in FM transmission). I've got the pinouts at the DMA8+ end from its installation manual, but I can't find anything on Odyssey's site telling me what the pinouts are going in to their box. Emailed them yesterday but no response so far - I guess because they're operating on reduced staffing. This is getting a bit urgent, though. Don't suppose anyone has the info?

[Steve Guttag]

The big trick to remember on the DMA8+ is that it is BALANCED OUT so all of those "-" terminals have to be tied to low/"E" for unbalanced devices. Have you tried emailing Mark? Many of their pinouts are not on their site but they will likely issue the pinout.

[Sean McKinnon]

On the Odyssey web site there is a picture which shows the rear of the unit and it appears to say "ECI/DAX" which I am guessing DAX refers to the DAX 202/602/802 line of products? These products supported both the DMA-8 and "USL" pinouts. I would try a straight through cable first as it may be DMA-8 to DMA-8.

[Leo Enticknap]

Thanks Sean.

This is what I have for the DMA8+ analog output:

dolby_outputpins.JPG

And here is what I've found for the USL DAX602/802:

DAX602_outputpins.JPG
So it looks like the only difference is for the wiring of the ToddAO/SDDS stage extra channels (not supported in the DAX); but that for regular 5.1, an old school printer cable (straight through, pin to pin) should work! No need for messing around with either a soldering iron or DB25<>RJ45 adapters and needle nose pliers would be nice.

Thanks again - I'll give that a try.

[Christopher Markiewicz]

Agreed, at West Wind we went from the DAX-602 analog out to DI6-3 in with a plain DB25 cable, then DI6-3 out to a small rack mixer with RCAs. Mixer out went to the transmitter.

[Leo Enticknap]

This is a very similar situation. The existing installation is exactly as you describe (IMS3000 > DAX-602 > Odyssey DI6-3 > consumer mixer > FM transmitter); but, we recently had a scare with the DAX-602 acting up. The site has several unused DMA8+s gathering dust on a shelf, so I'm trying to get one into service as a backup for the DAX-602. Will be at the site soon, and will let everyone know how it goes.

[Sean McKinnon]

Good Luck Leo! Glad I could (hopefully!) help!

[Sean McKinnon]

how did it work out?

[Leo Enticknap]

I'm going to have to leave you in suspense a little longer; sorry! Got sent on a last minute job to northern Nevada, as a result of which I won't be able to get to this site until next Wednesday. More news when I have it.

[Sean McKinnon]

lol, no worries!

[Leo Enticknap]

Still no update. I actually did get there on Wednesday, but had to fight another fire that used up all the time available. Still on the agenda for the next visit.

[Leo Enticknap]

Works beautifully. Used a pin-it-yourself RJ45 to DB25 adapter to take the AES audio from the IMS3000 into the DMA8+, using the pinouts in the latter's manual, and a straight through, pin-to-pin DB25 male to female to go from the DMA8+'s analog output into the DI6-3. All the channels light up as they should on the DMA8+ app when playing a channel ID DCP, I'm seeing a good level on the FM transmitter's web UI (BW Broadcast TX5), and dialogue from a feature sounds good and clear on my car radio.

The only potential gotcha is that if the IMS3000 is configured for channel assignments per ISDCF, then channels 7 and 8, which the DMA8+ thinks are left front extra and right front extra, are in fact HI and VI respectively. So if you actually need to use these channels, you will need to figure some way of splitting them from the other six coming out of the analog DB25 output. But as drive-ins are very unlikely to have HI and VI facilities (are they ADA exempt on this score? I've never seen HI and VI installed in a drive-in), I can't see this being a big problem.

Very useful to know that a DMA8+ can be used as an audio processor for a drive-in, as there are a crap ton of them lying around unused all over the place now.

[Steve Guttag]

Leo, if you think about it, HI is sort of built-in for Drive ins. The only extra would be VI and one would need another transmitter/frequency.

[Carsten Kurz]

We use a DMA8+ as the 'audio processor' for our open air screenings.

[Leo Enticknap]

Steve - good point. I guess you could use a regular cinema processor's HI output and send that straight to an FM transmitter in dual mono mode. The problem is that if the DCP doesn't have an HI track and the audio processor can't mix one down on the fly (which is essentially what the DI6-3 downmixer does - applies the center channel to L and R, and boosts it by a few dB), you've got yourself a silent movie.