AES Db25 pin cable from DoReMi to Processor

[Erik Olsen]

So my Dolby 650 will not start up anymore. A while back It started to use about 7 minutes to start up, and now nothing happens. And It does not help that the on/off button is the most useless button I have experienced. It is not possible to know if it is on or off. There is a red light no matter what. So I have to push the button and wait 10 minutes, then try again and so on.

But to my main question.
I got an Yamaha DME64N with 7.1 capability to replace my cp650, so of course I want to upgrade from the 5.1 to 7.1.
But the cable than runs from the DoReMi 2k4 to the processor is marked "Doremi 6 channel" so I guess it will only carry the 5.1 channel.
Can I use any Db25 cable I find? or does it have to be special made 7.1 for the DoReMi?

[John Thomas]

1: A long boot-up time on a 650 is a symptom of a failing power supply. Sounds like it finally failed.


2: No, a straight-through DB25 cable will not do the trick here, and nor will the existing cable.

I assume your new processor is using the MY8-AE96 expansion board to receive AES. That board uses the Yamaha pinout, which is laid out here: https://usa.yamaha.com/files/downloa..._datasheet.pdf.

Your DCP-2K4 uses the pinout referred to as "Doremi" or "DCI" in this document: https://c3f18fc2-65b9-4e62-8935-5869...448541075d.pdf.

You will need to adapt the pins in order for your new processor to receive audio at all -- you can do that with a custom cable or a board.


Upgrading to 7.1 will require a few more configuration steps, and likely more equipment than just a processor swap.


3: I'm weaker on the stuff that was before my time, so somebody feel free to correct me here: If your 650 was receiving AES in the first place then it must have a Cat. 790 board, which would also mean that your 650 already supports 7.1.

[Leo Enticknap]

The CP650 needs a firmware upgrade to support 7.1 with the 790 board, which isn't free (or at least wasn't when the 650 was in mainstream use). Can't remember the version number - I'm sure someone else here can. If you don't have it, email cinemasupport [at] dolby.com for pricing.

Now that Odyssey is out of business, the most viable way to make the cable is likely to use a pin-it-yourself DB25 to dual RJ45 adapter at both ends, and two cat6 cables between them.

[Adrian Avram]

Indeed, long boot-up time is happening because of a failing power supply.
However, to fix the PS, in 99% of the cases you just need to replace a couple of capacitors. There are two caps in the start-up circuit, i believe one is a 47uF/50V and the other one is 100uF/50V - dried up / leaky.
The other three are on the output stage (2200 uF/10V and 2 x 1000 uF/25V - all bulging).
If the repair is out of your reach, you can take it to a local repair shop. Attached is a picture with their location.

[Erik Olsen]

My 650 has EX card, and when the DoReMi was installed it is connected to a USL ECI-60, and then using the 6 channel analog input on the 650.
The surround channels are already wired L-R and back L-R.

@ John Thomas: Yes, the Yamaha came with two MY8-ADDA96 for analog in/out and one MY16-AE for the AES / EBU interface. Thanks for the links for the pin order. Have to try to figure this out.
@ Leo Enticknap: Thanks for the tip for DIY DB to RJ. I will be going this route. Just have to figure out the pin order.
@ Adrian Avram: When I have the time, I will look into the capasitors. Thanks for the info. Hopefully I can make it work again.

Thanks for the replies.

[Erik Olsen]

Some follow up questions.
Q1:
So the Channel 1 to 6 from Doremi (L/R) - (C / LFE) - (LS-RS) I will pin to the corresponding channels on the Yamaha MY16-AE. That uses 3 out of 4 available inputs on the MY16 card .
Should I then pin channel 11 and 12 from the Doremi to the channel 7/8 on the Yamaha to get the back L and R surround?

Q2.
On the MY8 datasheet: https://usa.yamaha.com/files/downloa..._datasheet.pdf
Does it matter which of the pins I use for ground? On the datasheet for the DoReMi every GRD has its own pin . But on the Yamaha the GRD is just mentioned at the end. GRD is just GRD right? If I wanted I could just ground them all on one pin? Or do they serve a purpose in decoding the AES signal?

Q3.
Is the word clock signal sent through one of the main channels from the Doremi?

Regards,
Erik Olsen

[Carsten Kurz]

You could wire 11/12 to MY16-AE 7/8. However, the Doremi also allows for software rerouting - so, even if you connected the Doremis 4th AES pair/7&8 to the MY16-AE 7/8, you can still configure a channel routing in the Doremi that feeds DCP channels 11&12 to output pair AES 4/ch 7&8.

The specific GND connection doesn't matter for AES. Also, the clock is contained within the AES signal. Every AES signal carries it's own clock. The MY16-AE could either derrive it's master clock from one of the AES inputs (could be AES1), or, reclock every input.

Is this a commercial cinema operation? You may need an additional AES signal for HI/VI-N then.

[Sean McKinnon]

Usually in a 650 the red light is illuminated when the processor is "off" and not illuminated when it is "on"

Is this a commercial cinema? Do you have external active or passive crossovers? Do you have the equipment and skills to perform a "B-Chain" alignment because you will need to set SPL's and tuning it is very unlikely but did your 650 have a crossover card? I hope you didn't buy this Yamaha specifically for this process as its really not the best option there are plenty of used cinema processors out there. Now if this is something you already had and are trying to use to stay on screen temporarily then that's another thing but you will have to setup your own "format" using the routing in the Yamaha and set a surround delay if the Yamaha contains a delay function (they usually do).

[Erik Olsen]

Strange, I remember the button on my 650 had the same red light off or on... But now I am not so certain anymore...

Yes,, we are a very small commercial cinema, I have an old Dolby 500 as standby that I got from an another cinema that upgraded their sound equipment, this unit is not aligned for our screening room, but sounds good. The surrounds are a little high but works well as a back-up. Luckily I had some cabels made up for fast exchange since the output channel connectors between the models are different. That cable really saved the day. Actually this Yamaha is from the same cinema as they upgraded to Atmos.

We have an external crossover. When It comes to aligning the sound, I will call in the proffesionals. But I have to say it would be fun to get the equipment and try to learn to do it my self. But for sure that is some expensive stuff / software needed.

I'm on this mission as a learning experience, I have the 500 working, so I can take my time to learn how to set up this Yamaha. And hopefully if something fails in the future I have the knowledge to save the day instead of having to cancel shows.
I don't think we use the HI / VI-N here. If I understand this correctly it is a narrative soundtrack? But we do have audio induction loop for hearing aids.

[Steve Guttag]

Little known fact, the button on the CP650 is the "Bypass" button, not, technically the power button though yes, it does turn the main supply on/off. You'll note, when the button is lit and the unit appears dead, the P1/P2 LEDs still light and optical sound will still pass through its bypass circuits and the changeover connections will still function.

[Leo Enticknap]

I don't think we use the HI / VI-N here. If I understand this correctly it is a narrative soundtrack?

On most mainstream studio feature DCPs, there are two audio tracks on the DCP that are nicknamed the "ADA [Americans With Disabilities Act] amenities" here. Channel 7 on the DCP is the hearing impaired (HI) channel. This is typically a center-weighted mixdown of the stage channels, which the customer listens to through a pair of headphones that receives it either via an infra-red signal bounced off the screen, or a radio transmission. The idea is to assist someone with poor midrange hearing in understanding the movie's dialogue. Channel 8 is the visually impaired (VI) track. This is a scripted commentary that describes action in a movie that is not apparent from the soundtrack (in other words, action on the screen that you have to be able to see clearly to understand). The purpose of this is to assist a customer with poor eyesight, but good hearing. Again, this is delivered to the viewer via a headset that (s)he collects from the box office on arrival, and returns after the movie. The employee handing over the headset configures it to determine which auditorium it'll be used in, and if it is to play the HI or the VI track, before handing it over. The equipment in the booth is a "set and forget" one-time install. There are various ways of taking AES channels 7 and 8 on the DCP into the transmitter: they vary a bit according to what audio processor and HI/VI system is installed.

Arthouse and minority interest DCPs are a lot less likely to have HI and VI tracks, largely because of the cost of producing them. Although it is very easy to produce an HI track: you could even do it using a free tool such as DCP-o-Matic, by applying a mix of the three stage channels to channel 7 on the DCP, with the center boosted by a few dB, and the left and right attenuated. For a VI track, however, you would have to script and record the commentary. You would need an eyesight expert to consult on the script's content (in writing the script, you have to try to make sure that there is no talking over dialogue, and that there only is if it is more important for the listener to understand the visuals than the dialogue) and a professional voiceover artist to do the recording, to achieve a decent result. There is no cheap hack for that.

[Carsten Kurz]

I guess the Yamaha DSP would be able to create a HI mix from L/C/R in realtime and feed it to the induction loop. I have no idea about legal HI/VI-N requirements for commercial cinemas in Norway.

I understand the Yamaha DME64N is/was quite popular in Scandinavia. A colleague installed quite a few units there, at least before the AP20 became popular. If that specific unit was installed in a cinema before, I guess most of the necessary functionality is already programmed in it. Maybe they can tell you who implemented it.

[Leo Enticknap]

I guess the Yamaha DSP would be able to create a HI mix from L/C/R in realtime and feed it to the induction loop.

The CP650 can, too. This feature seemed to have been widespread in film era equipment, but dropped from DCP era equipment, likely in the expectation that from then on, the HI track would be baked into the DCP and there'd be no need to create it on the fly. In DCPs of mainstream titles it is, but if you play a significant volume of arthouse movies, you can't rely on that.

[Steve Guttag]

Leo...what "cinema" processors, at this point, do not have an L/C/R mix for HI (speaking of canned solutions, not drag-n-drop dsp). From QSC, DCP, DPM, JSD all provide for a mix instead of a dedicated track. The CP950 does as well as the CP850 (I think...I don't have any to check but I believe it configures like the CP950). I don't have any first hand knowledge of the Trinnov and I would presume the AP20/25 could handle such a trival task. So just which processors, in production, don't provide for an L, C, R mix in lieu of a dedicated track?

[Mike Babb]

Steve, for Trinnov there are dedicated HI/VI outputs that have the track from the DCP on Ov1 and 2. The Ov1 has an option to send a downmix of LRC instead so you could get audio during a bluray for example. The last version of Ov1 and all Ov2 have the option to determine the level and channels in the downmix which would be on the Aux1 and Aux2 outputs.