Sound output issue from a Dolby CP650 with cat790 used for digital cinema projection

[James Norman]

Hi. Ive recently acquired a dolby cp650 sound processor with cat790 installed which had been kept safely in storage for the last several years. It is now cabled up to a barco dp2k8s projector feeding it AES audio streams. The dolby cp650 is outputting nicely 5.1 test noise and 2 channel non sync audio to an onkyo reciever via RCA input. However im not getting sound from the projector via the cat790 DSP board. I was wondering if anyone could offer tips about what the problem could be. CP650 bootup shows up no serious errors, however saying that, im stumped as to where to find the comprehensive error log from both the cp650 interface and the pc dolby software program. Any help, greatly appreciated

[Dave Macaulay]

Of course the card could be bad, I have not seen that though.
First I would confirm that the 4xAES input is wired correctly. That option I/O connector gets very busy with the surround outs and digital ins. Using an Odyssey in/out card is best I think, if they are still available.I assume you have an IMS or ICMP, and their card with RJ45 connectors makes hookup super simple and reliable.
If your receiver has a wired S/PDIF input, you can connect the server outputs one at a time there to confirm that digital audio is present. AES has a slightly different signal spec but usually they are compatible.
I think that all CP650 software versions support the 690 but only the latest version will do 7.1, and only fairly late versions will do EX (decoding surrounds to left/right/rear).

[Sam Chavez]

Dave has it covered as far as I can see. I'll have to look at one in my shop to see about the error log. It should show up in the "about this 650" section. It is possible to plug a 790 in backward. I've tried to in any case. I did buy up some of the 650 accessories from Odyssey as they were closing. It makes for a much easier installation.

[Steve Guttag]

The CAT790 is not an original card so not all versions support it, as I recall but I don't have it committed to memory when the CAT790 was supported. The original "EX" card (CAT794, I think?) only supported a single AES stream but it was selectable between Balanced and Unbalanced (AES3 and AES-3id) via links.

The CP650 clocks off of pair 1 (Left/Right) so if there is anything wrong with that wiring, you'll get nothing.

[Adrian Avram]

First - does the CP650 "see" the 790 board? Scrolling through the menu - is the message"Cat.No.790 installed" displayed ?

Second - what is the SW version of the unit?

The CP650 clocks off of pair 1 (Left/Right) so if there is anything wrong with that wiring, you'll get nothing.[/QUOTE] - check that also - happened to me, the "Channel 1 +" wire broke in the connector - no sound output.

[Leo Enticknap]

It would be a bit strange if it had the 790 card in it, but a firmware version that did not enable that card to work. It shouldn't have shipped from the factory in that state, and if the 790 card was installed later, you'd expect that whoever installed it would also have updated the firmware, to get it to work.

If I remember correctly, the DB25 pinouts on that input are a PITA: the grounds for all the pairs have got to go to one pin, or something like that. I remember once having to frankenpatch/field modify a pin-it-yourself RJ45 to DB25 adapter using terminal block and gaffer tape to get a Barco Alchemy to feed AES into a CP650.

[James Norman]

Hi all. I installed a new 790 card to check it was that. Still no sound.
the message"Cat.No.790 installed" is displayed
cp650 software version is 2.3.6.6
The unit is cabled up to the barco ICMP via an RJ45- db25 connector
Regards wiring to specific pin inputs on the I/O connector of the cp650, can this be simply done by choosing the AES audio channel outputs from the barco communicator?
Will i need to do any soldering at any point?
And also does the 'immersive sound settings' have to be enabled in the communicator setting

[James Norman]

As im not sure immersive sound settings are relevant to my issue, the attached pic showing the test for it, may be unrelated, but here it is....

[Adrian Avram]

on SW 2.3.6.6 the Cat. 790 should have no problem. What button is assigned for digital sound and more important what format, in the CP650 ?
Is it Format - 88 "6Ch PCM" ?

[James Norman]

Hi Adrian
Button 11 is assigned for digital sound. Format 88 6ch pcm

[James Norman]

Audio channels on the communicator are set to default

[James Norman]

..is immersive sound relevant?

[James Norman]

cp650 format window

[Carsten Kurz]

Immersive is irrelevant on the ICMP, but you should probably disable it altogether. Are you sure your audio cables are wired properly?

- Carsten

[Leo Enticknap]

Here are the AES RJ45 output pinouts for the ICMP:

alchemy_AESpinouts_1.PNG
alchemy_AESpinouts_2.PNG
...and here are the CP650 option card DB25 input pinouts:

cat790_pinouts.PNG
This should give you the info you need to make up a cable.

The way I'd do it would be to use a dual RJ45 to DB25 connector, e.g. an L-Com model RA2588M, at the CP650 end, and route the pins according to the above tables.