Film-Tech Forum ARCHIVE: DTS & SRD into a CP65

This is topic DTS & SRD into a CP65 in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Greg Mueller (Member # 17) on 05-18-2003, 02:21 PM:

Maybe this has been covered before, if so a referral would be appreciated.
I want to hook both SRD and DTS to my CP65. Is there a way to hook both up at the same time through a switch etc. so which ever is being used will kick the CP65 into digital without having to physically unplug plugs and wires etc?
I'm also using a Smart Afterburner
TIA

Posted by Brad Miller (Member # 2) on 05-18-2003, 02:26 PM:

It's been a few years since I hooked up that combination on a screen, but I do remember it can be done. However one of those screens would auto-switch between the two formats and the other screen (wired identically) had to have the format you were not using turned off. I never did get it resolved because the projectionists did not believe it was any major issue and soon thereafter it was decided not to "double stack" auditoriums and spread the digital players around to analog screens.

Posted by Greg Mueller (Member # 17) on 05-18-2003, 02:35 PM:

I wouldn't mind turning off the unused format. I'd just not turn it on in the first place, I guess. One guy I asked suggested getting one of those DB25 switch boxes and switching back and forth between the two. But he never figured out a switch for the "kick into digital" trigger

Posted by Brad Miller (Member # 2) on 05-18-2003, 03:37 PM:

Pin #25 on the DB25 connector is your "pulse to digital". I forget which pin is "pulse to SR", but it is in the DA20 manual as well as the dts6-d manual. You could get a DPDT switch for that or use two DB25 switchboxes. The easier solution would be to use the dts CP65 automation breakout board, as it has connectors for both units. At that point you would only need to swap the DB25 audio connector or you could use a DB25 to fanning strip cable for the DA20 and the dts CP65 audio breakout board for the dts (both connected to the digital input). Just make sure you have one powered down at all times. Then again, it seems I routed the dts signal through the DA20, because I remember I did not have to change any wiring to switch between formats.

I'm sure there are other ways to do this. If no one else has a better recollection of the CP65 wiring, I'll take a look next time I'm near one.

Posted by Gordon McLeod (Member # 33) on 05-18-2003, 03:43 PM:

Which DTS do you have if it is the DTS 6 then connect the da20 output to the input of the DTS flowthrough relays and the otuput to the cp input and conect the logic (digital/SR through a toggle switch to the automation input

If it is the DTS 6d one would need the cp200 relay board for the dts6d

Posted by Greg Mueller (Member # 17) on 05-18-2003, 03:46 PM:

I've got the 2 drawer dts unit

Posted by Steve Guttag (Member # 268) on 05-18-2003, 10:30 PM:

Greg, anything is possible. Pin 25 BTW is the projector #2 changeover logic pin on the CP-65 and DA-20 (and Panastereo, for that matter).

You can certainly share the one digital input on the CP-65.

There are versions of the control breakout boards from DTS that will block the DA-20 from seeing the DTS select Digital. The CP-200 audio breakout board will be essential to switch the audio between the DTS and DA-20.

I think if you do a search on the various topics...I gave a description on how to do this.

Steve

I believe this link will get you to my previous description with a CP-65 (page 1)

Click Here

[ 05-19-2003, 06:25 PM: Message edited by: Steve Guttag ]

Posted by Ken McFall (Member # 845) on 05-19-2003, 12:56 PM:

Greg I did this recently on a CP55, which is basically the same as a CP65. I was using the DTS6, three drawer unit.

I wanted to make DTS the primary digital format. Thanks to some ideas from the guys on here and my own thoughts I was able to make it work exactly as I wanted with full reversion down from DTS to SRD to SR and back. Its been working faultlessly for some months now so its proven and reliable.

YOu need an interface card with six relays on it and have to do quite a bit of soldering to make the leads but as its not an off the shefl option its the only way.

If you need any further info drop me a mail and I'll try and help out.

Posted by Mike Rendall (Member # 1499) on 05-19-2003, 03:40 PM:

Done it already in our theatre. It is really easy - Speak to Karen and get a dts breakout board and another cable (can't remember the serial number but it is in the back of the dts manual). Wire it up and hey presto! I can even give you a circuit that you can build up which runs a set of LED's to show you which format is active at anyone time (you can effectively switch between dts & SRD on the fly.)

Our theatres website is Union Films. There may be some tech stuff on the website UF Refurbishment

I am getting around to putting in a formal picture submission to Brad, just got to get down there when it is quiet!

Mike

Posted by Brad Miller (Member # 2) on 05-19-2003, 05:31 PM:

Mike, that circuit sounds like it could be useful to many people. If you would pass it along to my email as well as Greg, I will add it to the tips or manuals section. [thumbsup]

Posted by Greg Mueller (Member # 17) on 05-26-2003, 10:28 AM:

Looking around in the back of the DTS manual I found a diagram that shows that you need to plug in the "JM-11 Ribbon Cable" (from the DTS unit) into a "D462-01 Adapter Cable" and that into the "Audio To CP" (J8) plug on the back of the DA20.
Then a DB25 male/female cable from the "CP Sense Control" (J6) to the "D496 Logic Card" which is plugged into the "J18 Connector" on the back of the CP65. It also says (as suspected) "The power on the SRD must be off when playing DTS". I suspect they mean the DA20.
So all I need is the D462-01 Adapter Cable and a DB25 M/F cable about 3' long.
Maybe an Either/Or switch sending AC power to either the DA20 or the DTS unit would be a good safe guard.

Posted by Mike Rendall (Member # 1499) on 05-27-2003, 03:15 AM:

Hi Greg,

I have had a look in the back of the dts manual. The board you need is on page 65, It is called a dubbing interface (D725). The way it works is as follows :

1) If everything is wired correctly, the sound that will appear at the digital input on the CP65 is the feed from the Aux input (or dubbing input) This will be where you hook up the cable from the DA20. So, in this configuration the system will behave exactly as a normal SRD (65/DA20 combo)

2) If a dts movie is playing, *and* the dts6d is powered up and running *and* the timecode is read correctly then the relays will switchover to the second socket and now the sound from the dts system will be fed to the CP65. This happens because when the dts is active, pin 10 of the automation connecter is grounded which completes the relay circuit and throws the system over to dts.

3) If the dts fails (rarely) it should drop straight into SRD maintaining a digital through feed, if this fails it should then drop into SR. For this to work properly you need to put a solid state relay into the automation connector which would prevent the dts system from knocking it straight into SR when it fails but rather using the DA-20 automation to do this.

I will sort out the circuit diagram to do this, it is quite straight forward and has worked well for the last 6 years in our theatre (so I am a little rusty on the specifics). I have had a delve but cannot locate my original diagram so I am going to have to work it out again from scratch.

If you are going to solder the pads for the power feed to the automation connector then remember to remove it (and test it on a multimeter before connecting it to the D725 just in case you catch the wrong wire!) It would have been much handier if dts had installed a switchover system inside their unit.

Hope this helps.

Mike

Posted by Greg Mueller (Member # 17) on 05-27-2003, 09:41 AM:

I have only a DTS-6. My manual doesn't seem to have that board listed.

Posted by Mike Rendall (Member # 1499) on 06-11-2003, 05:14 PM:

Hi Greg,

It looks like my original reply got lost in the server downtime. The manual I was refering to is for the DTS 6D. I think the pinouts are the same (should be for the audio) and hence should work with a dts-6.

I promise that I will send the diagrams etc into Brad, but I have lost my originals and will have to retrace my steps through the circuit board and redraw it. - May take me some time.

Mike

P.s. Nice pictures of your observatory on your website.

Posted by Mike Carro (Member # 232) on 06-11-2003, 07:38 PM:

Greg, We have the same situation. I have my 2 drawer unit and my SRD hooked up to the CP 65. I've never been able to interchange between the two with out shutting one off.

Posted by Greg Mueller (Member # 17) on 06-12-2003, 09:17 AM:

Well I've got another interesting problem. I've got them both hooked up using the D462-01 adapter cable from DTS and a generic DB25 male/female 3' cable as illustrated in the back of my DTS 6 book.
I should add that I've also got the output of the DTS unit running into a Smart Afterburner (which I really like) and then into the CP65.
If I have both of them plugged in but only the DTS unit turned on, the Afterburner makes a loud humm in the speakers when switched on. If I unplug the DB25 cable from the back of the DA20 it goes away.
I talked with Oscar at Smart and he thinks it might be a ground loop and suggest a fix which I haven't tried yet.
I think I will put my DB25 breakout box in line and see if I can figure out which line is making it. (Hopefully not one the unit needs to function).
A friend who has a similar setup without the Afterburner, uses a DB25 switch box in his system to switch between his DTS 6 unit and the DA20, which leads me to believe it might be in the DB25 line.
The adventure continues.....

Posted by Gordon McLeod (Member # 33) on 06-12-2003, 09:43 AM:

A ground loop is probably the culprit mostlikely between the dts and da20

Posted by Karen Hultgren (Member # 395) on 06-12-2003, 01:45 PM:

Greg - when connecting DTS to a DA20, it's best to turn off the unit not in use. Use only one.

If you are using a self-powered subwoofer, they can sometimes produce hum (if only the sub is humming).

When it comes to grounds, remember that circuit ground and earth ground should not be common. Connecting them together will most definately produce a ground loop.

Karen at DTS
khultgren@dtsonline.com

Posted by Greg Mueller (Member # 17) on 07-04-2003, 09:09 AM:

Ah Ha!
There was a grounding problem. I guess it must have been between the DA20 and the Smart Afterburner. Oscar suggested that I disconnect the ground lug of the fanning strip that hooks to the CP65 from the Smart device. I took out the ground lug holding screw and bent that lug back and it quit humming. Seems to work fine without it.

Posted by Greg Mueller (Member # 17) on 08-09-2003, 12:16 PM:

The final solution.....
I finally got it all working correctly. The main stumbling block was getting the Smart Afterburner in the equation. I talked with Oscar at Smart and we decided to put the Afterburner after the CP65 and before the power amps. (Didn't know you could do that) Everything works fine now. I just don't power up the digital unit I'm not running.
That Afterburner is a pretty versatile unit. Many thanks to Oscar for his troubleshooting time.
The down side is that now I absolutely have to get longer Belden wires going to the amps.
It's always something

Posted by Oscar Neundorfer (Member # 458) on 08-11-2003, 07:30 AM:

Greg,

You are welcome for the help. I am glad you got it all working to your satisfaction.