Film-Tech Forum ARCHIVE: Digital sound on Kinoton FP-30D.

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Posted by Stephen Furley (Member # 1277) on 08-08-2013, 10:22 PM:

Is it possible to mount Dolby Digital and/or DTS readers on FP-30 with standard column and still retain the ability to run 1800 m (6000 foot) spools? I've seen a DTS reader mounted on one, but that was a single machine with tower, and I can't remember if its position would still allow 6k spools to be used. I've never seen a Dolby penthouse reader on a Kinoton, only Cinemeccanica and Century.

Could it be done by making up custom brackets and mounting them on the front of the columns, or even on the front wall of the box? What's the maximum distance that these readers can be mounted above the gate?

Does anyone have any pictures of such an installation?

Other than the readers and a DA-20, what else would be required to do Dolby? Processor would be a CP-65 and DMA8+. Can all of the cables be made up from readily available parts, or are any strange connectors involved? What about the motor start relays for changeover operation; are these anything special?

Just having some thoughts at the moment. The equipment can be found cheaply now, but I suspect that the installation costs would be quite high, and it would only get occasional use.

Posted by Sam D. Chavez (Member # 1841) on 08-08-2013, 11:13 PM:

The Dolby SR.D readers or the BACP version can be mounted on a heavy duty L bracket on the front, back, or on the front wall. There is plenty of delay available so no problem there. Reader video cables come pre-made at 30 or 50 Feet and there are plenty of those around at the moment. The logic cables are DB25, the audio cables for the 65 are DB25 to Dolby red fanning strips.

Motor relays are just ordinary SPDT. The coil voltage just needs to match the motor voltage and the dry contacts are to signal the DA20 which projector is running.

Posted by Stephen Furley (Member # 1277) on 08-08-2013, 11:45 PM:

Sam, thank you for the reply.

It's a couple of years since I've seen it, but I seem to remember that when used with a DMA8+ the DMA connects to the 'Digital' input on the CP, and the DA-20 connects to the DMA, so that different (25 pin) cable would be required; is this correct?

Posted by Sam D. Chavez (Member # 1841) on 08-09-2013, 09:40 AM:

There are a couple of ways to interface the DA20 and DMA8 to the 65. The easiest way is to feed the DMA8 out to the external input of the DA20. The audio goes in and out of the DA20 bypass relays when they are relaxed and only requires a DB25M to DB 25F cable that is easy to obtain.

Posted by Scott Norwood (Member # 30) on 08-09-2013, 09:56 AM:

Note that the DMA8+ has a balanced output, while the DA20 does not.

You will need to make your own cable to connect the DMA8+ to the CP65; the regular DA20 cable will not work. There is a Dolby installation note about this.

Posted by Gordon McLeod (Member # 33) on 08-09-2013, 11:00 AM:

Also I beleive that some if not all DA20's do not have a passthrough for the sub

Posted by Stephen Furley (Member # 1277) on 08-09-2013, 11:06 AM:

quote: Scott Norwood
You will need to make your own cable to connect the DMA8+ to the CP65; the regular DA20 cable will not work. There is a Dolby installation note about this.

Scott, the DMA*+ is already connected to the CP-65, or at least it was when the cinema was open, it was disconnected and sitting on top of the digital projector when I saw it last week, but it's due to be reconnected soon as part of the re-instatement of the digital cinema. The question is how to add a DA-20 to the system. I thought I saw it in the manual with the output from the DA-20 passing through the DMA8+ to the CP-65, but Sam seems to be saying the opposite. I know that the combination of DA-20, DMA8+ and 6P-65 is possible, I've seen it in several places. What I wasn't sure about was mounting Dolby Digital readers on the FP-30Ds without obstructing the use of of 1800m spools.

I don't know yet if this will come off, and can't say too much about it until the re-opening is made public, but it does seem that it's technically possible. I'm going to try putting the idea to the management next week.

Posted by Sam D. Chavez (Member # 1841) on 08-09-2013, 12:59 PM:

The DA20 can go through the DMA8 but it's usually done the other way around. I was thinking of DTS being routed thru the DA20 more than DMA8.

As to subwoofer pass through on the DA20; DA20's with 611A control card will pass sub signal, older 611 cards will not.

Posted by Tony Bandiera Jr (Member # 2365) on 08-10-2013, 11:43 PM:

Stephen: If you do a penthouse reader on the FP 30, and your perf delay ends up greater than say 150 perfs or so, be careful: see my post dated 8/10/13 (page 4) of this thread: CP650 sound "wow" on changeovers running Dolby Digital... so you don't run into the problem I did. [Big Grin]

You will possibly need to shorten the acceleration time on your projectors to avoid the issue I had.

Posted by Stephen Furley (Member # 1277) on 08-12-2013, 03:41 AM:

Tony,
Thanks for the tip; I'll keep it in mind.

At the moment it's still not known if this will go ahead. The manager that I need to put the proposal to seems to be away at the moment, but I don't know how long for. The equipment is available, and I could afford to buy it on credit card and pay for it over two or three months.

If this does happen the equipment would just go into store for at least a few months while I find some way to raise the cost of installing it. That would cost more than buying the equipment, but I don't know how much. I do know a number of people who have said they would contribute to the cost. If the cinema gives permission then I think it's likely to go ahead, but I can't even ask them yet.

As I understand it there is a small amount of money available to get the cinema open again, but this can only be used to get thedigital projection system re-commissioned. They want to keep the film equipment but any costs involved in getting it running again would have to be met from elsewhere; there could be no cost to the cinema. At the moment one projector is completely dead, even the lamphouse fans don't run, the breaker in the panel hasn't tripped so at the moment I don't know what the problem is; I only had a few minutes to look at the equipment two weeks ago. If there's no power getting to the machine at all it's not going to be anything serious.

Posted by Pete Naples (Member # 761) on 08-12-2013, 01:09 PM:

Stephen,

Do or get the cinema to do, a bit of begging around the circuits.

There's LOADS of decommissioned FP30D's around, which are begging to donate a reverse scan + basement reader rep-set to yours.

The Kinoton reverse scan head really is the best around, it just works. Also it will not interfere at all with spools nor would there be any possibility of a delay issue like Tony has detailed.

You can mount DTS heads on them, best way is with the pukka Kinoton bracket. but to be honest in this day and age I wouldn't bother.

Posted by Stephen Furley (Member # 1277) on 08-12-2013, 01:50 PM:

Pete,

That's a possibility. Were many machines actually fitted with those reverse scan readers; I think I only ever saw one place that had them.

I'm looking into the possibilities, but I still don't yet know if the cinema will let me do anything.

Posted by Tony Bandiera Jr (Member # 2365) on 08-12-2013, 09:23 PM:

Pete made some very good points...if you can get the basement readers it would be a better bet. (no delay issues). As for the DTS reader mounting, check out my pictures here: UCI HIB 100

I did that because the morons who spec'd the projectors had 4-track mag heads in the DTS reader locations..but the use of the lens turrets threw the sound WAY out of sync for mag use. The davis loop capstans make for a really stable timecode read path though.

Posted by Stephen Furley (Member # 1277) on 08-13-2013, 02:04 AM:

Pete, I'm sending you a private message.

Posted by Stephen Furley (Member # 1277) on 09-13-2013, 05:15 PM:

quote: Sam D. Chavez
The DA20 can go through the DMA8 but it's usually done the other way around. I was thinking of DTS being routed thru the DA20 more than DMA8.

Sam,

I have the DTS-6D and DA-20 to CP-65 diagram from the DTS 6D manual in front of me and there are a couple of things that I don't understand. The six channel analogue audio out from the DTS goes to the 'Audio in from CP' connector on the DA-20. Presumably the DA-20 passes this through to the CP-65 via its 'Audio out to CP' connector when running DTS, and outputs its own analogue converted audio on the same connector when running SR-D, but how does the DA-20 make this selection? Analogue conversion or passthrough can be selected on the DMA8 plus by means of the front panel buttons or the automation input, but how is it done on the DA-20? Surely the DA-20 doesn't just switch to passthrough when it does not receive a signal from the Dolby Digital heads, does it? I thought that situation would cause it to pulse the CP-65 to analogue SR format.