Film-Tech Forum ARCHIVE: Split optical surrounds on CP-200?

This is topic Split optical surrounds on CP-200? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=008415

Posted by Raymond Watson (Member # 3644) on 12-13-2006, 02:02 PM:

Hi all,
I have been doing some reading, I guess not enough, to find out how to modify a cp200 to split the surrounds in optical format.

I am trying to dig up a signal flow diagram for a 200 , (the one in the downloads section is missing)........ anyhow.....

It has been mentioned on here many ,many times, that anything can be done with one of these babies. I want to know how to split my surrounds in optical.

I use an SRA5 and the parabolic EQ's on a 560 for P and Q,I do not have an accessory unit.

I am aware of the optical stereo surround control line on JM25 and the cat. 153,and the "future" outputs for optical P and Q from the cat 150 at JM10 pins 8 and 20.

I am aware that vectoring may play a part in the process, and will admit up front that while I understand a vector. I do not understand vectoring in the audio unmatrixing world......LOL

Come on guys give me a little help here, I am sure it can be done. Whats the big secret.................?
I am sure it will not void the warranty on my cp200 to make the mods.
I should be recieving the flow diagrams in a day or two.... anyone got any pointers on where to start? [Smile]

Ray

Posted by Brad Miller (Member # 2) on 12-13-2006, 02:21 PM:

"Stereo surrounds" from an optical source will never happen. You can however obtain the same MONO surround signal from P and Q (also S) on the cat117/517 cards.

You have to have digital or 70mm magnetic format 43 in order to achieve actual stereo surrounds.

Posted by Raymond Watson (Member # 3644) on 12-13-2006, 02:29 PM:

Thanks Brad......

By the way, I got my first bottle of Film-Guard and a box of pads the other day...... put it on a 10 year old print..... all I can say is.... I am impressed!
Ray

Posted by Louis Bornwasser (Member # 3063) on 12-13-2006, 05:25 PM:

In the real world, Brad is correct. However, Dolby did offer a "pentoptical" module for the CP-100 which untied the 2 matrix outputs that are normally summed on the old 116 card. Somwhere I actually have one. Louis

Posted by Gordon McLeod (Member # 33) on 12-13-2006, 06:51 PM:

Wasn't the pentoptical module the same as the 110 card to get the derived centre channel

Posted by Raymond Watson (Member # 3644) on 12-14-2006, 10:03 AM:

so to make it short....

Optical tracks do not have the surrounds information split into stereo.

The surround info is never split into "stereo P and Q" in the processor or control unit.

Correct?...................... Thanks.... Ray

Posted by Sam D. Chavez (Member # 1841) on 12-14-2006, 10:33 AM:

Optical P and Q outputs are the same as the S, that is is to say, they all are the same, mono output.