Film-Tech Forum ARCHIVE: Alternative scaler types etc & D-A conversion

This is topic Alternative scaler types etc & D-A conversion in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Lindsay Morris (Member # 1430) on 07-24-2013, 02:31 AM:

Just tossing around in my mind whether to close or convert to Digital and going through the various costs with a couple of installers they all seem hellbent on ONLY using Dolby CP750 for audio decoding of the sound.

My needs in an outdoor situation are rather basic as currently run L C R & mono surrounds and works fine with good sound.
In addition I would like to be able to screen alternative content from either laptop or DVD/Bluray so naturally need a scaler so by the time that cost goes on top along with a CP750 for audio the costs increase quite a bit.
I then stumbled across a Gefen Scaler which also can decode the bit stream from the server and is easily connectable to my existing processor which already has a Digital input where the L C R & S signals from the D-A conversion can go straight in and onto the power amps via the Eq cards in the processor.
Thus there is NO need for a CP750 and all the surplus guff inside that for Dolby pro logic for optical sound and the Dolby Digital decoding from film source. All redundant bits with NO film running but I am paying for it.

Has anyone any experience with the Gefen scalers?? Pro/Cons etc.

I am attempting to do the conversion as cost effectively as possible bearing in mind that for 7 months of a year the gear will lie idle so having bloated bits of gear installed is not on my agenda.
The Christie Solaria One + is looking like a suitable machine but might be struggling to find a suitable lens in which case the NEC units with UHP lamps are looking attractive.

Am beginning to think that most of the installers here in Australia have blinkers on and cannot look beyond the familiar box.
[Roll Eyes]

Posted by Carsten Kurz (Member # 5396) on 07-24-2013, 07:16 AM:

What is you current processor?

You don't necessarily need a scaler for alternative content. At least not if it is all DVI/HDMI based. Laptops can output 1080p/i, DVD/BluRay Players just the same. A scaler may offer some tweaks, but depending on your projector or media block, it may not be necessary. We play alternative content often, and never needed a scaler for it.

USL and Doremi have solutions for processors and D/A conversion. Also, the DTS XD10P is a nice second hand option and can be found on ebay for as little as 500US$.

- Carsten

Posted by Clint Koch (Member # 1179) on 07-24-2013, 12:56 PM:

USL, Inc. JSD-60 is a good option.

Posted by Dave Macaulay (Member # 813) on 07-24-2013, 02:02 PM:

The CP750 doesn't have any of the "surplus guff" you name. It's digital only, no film "guff" at all. There are alternatives with similar feature sets. The price of these may seem high, but with a digital processor you don't need a D-A converter (not cheap).
You don't absolutely need a scaler to do alternative content. Most computers have HDMI out and Blu-Ray players can usually be made to scale to 1080p whether you play a Blu-Ray or just a DVD. 1080p is effectively identical to DCP flat, just a few pixels narrower. You just need an HDMI-DVI cable to feed the video into the projector.
For sound you can use a digital audio stripper box that takes the digital audio signal from the HDMI cable to send to the processor (assuming it's a CP750 or similar). If you happen to have an IMB system most of them have a HDMI input, which will put the HDMI audio onto the same feed the DCP sound goes through.
You can connect a player's optical or coax digital audio output to a processor digital input as well, and not use an HDMI splitter. A computer can connect with analog cables but using an HDMI stripper is much better if there's no digital audio output.

Posted by Harold Hallikainen (Member # 5405) on 07-24-2013, 07:52 PM:

The JSD-60 can decode Dolby Digital and DTS on the coax and Toslink inputs. If you want to stay with mono surrounds, it can generate that also.

Harold

Posted by Lindsay Morris (Member # 1430) on 07-24-2013, 09:04 PM:

Thanks all for your responses...has cleared away some of the mystic re this newer stuff.
I think that who I am dealing with are just salesmen who are responding from a set script and are about as clued up on digital as I am. [Smile]

More food for thought as the crunch will come at the end of this coming summer season when I make the decision to convert or cease.
So far have enough 35mm film titles available to see the coming season out.

Interesting that the CP750 has no film decoding bits in it and maybe all I need is a D-A converter such as possibly the USL DAX 602.
Then its audio can go straight into the Australian made Associated Sound processor's digital audio inputs.
When I acquired that unit I set it up with a custom made remote control box into which I inserted 4 LED level meters and audio monitoring facilities so they are on the front wall nice and handy.
The sound rack is mounted off the LHS rear with all the non sync stuff there (CD player, tape deck, tuner etc)
I cannot see the point of ripping all that out and reworking it all when it works so well as it is...operationally. [Smile]

I like a KISS setup.

Lindsay

Posted by Carsten Kurz (Member # 5396) on 07-25-2013, 06:21 AM:

quote: Lindsay Morris
all I need is a D-A converter such as possibly the USL DAX 602.
Then its audio can go straight into the Australian made Associated Sound processor's digital audio inputs.

Why would you need a D-A converter if this 'Associated Sound processor' has digital audio inputs? Do you have a link/website to that processor?

- Carsten

Posted by Lindsay Morris (Member # 1430) on 07-26-2013, 04:38 AM:

Carsten,

The processor has multiple analogue inputs selectable by the applicable press button none of which can decode the audio bit stream.
So that must go thru a D-A converter to give me the L ,C, R & S outputs at line level which then get hooked up to the input labelled Digital.
As I said I am looking for the most expedient way to convert and digging in my heels to some of the quoting types when they try to convince me that I "need" to replace the entire audio system as it is not capable of handling digital signals.
[uhoh]

The system as it is can make an awful lot of noise if I wind up the levels such that it becomes uncomfortable to patrons.
I can walk 100m into the bush past my carpark and hear every word said at those sorts of settings. So the digital dynamic range is NOT going to be an issue...tons of headroom. [thumbsup]

Posted by Carsten Kurz (Member # 5396) on 07-26-2013, 05:25 AM:

quote: Lindsay Morris
The processor has multiple analogue inputs selectable by the applicable press button none of which can decode the audio bit stream.
So that must go thru a D-A converter to give me the L ,C, R & S outputs at line level which then get hooked up to the input labelled Digital.

So that input is only 'labeled' for digital, but is still an analog multichannel input?

You play outdoors, but it's not a drive-in, right?

- Carsten

Posted by Antti Nayha (Member # 4980) on 07-26-2013, 08:03 AM:

I've never been too happy with Gefen scalers, even though the HDMI audio / Toslink feature is a nice thing to have. Also see this earlier thread.

Posted by Lindsay Morris (Member # 1430) on 07-26-2013, 05:56 PM:

Carsten,

That is correct a multi channel input labelled Digital and is capable of also doing stereo surrounds if needed but in my case NO as only mono required.
You are also correct it is an outdoor venue...300 seats, 10m screen @35m throw currently running a Century CC with VG image and sound with only 1600W on the lamp..solid screen + twin shutters = lots of light.

Antti,
Thanks for that pointer to the other posting. Seems like I will have to refine my searching capabilities as initially Gefen threw up nothing when I looked first up.
Seems however that I will not need a scaler with what I have and only need to decode the digital bit stream and send that through the current sound system.
Things are becoming much clearer.

Lindsay [Smile]