Film-Tech Forum ARCHIVE: SR Cat 280 to 280T mods

This is topic SR Cat 280 to 280T mods in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Brad Morris (Member # 1175) on 11-15-2004, 12:07 AM:

Does anyone have the sheet that describes the jumber mod. needed to convert the Dolby cat. 280 to a 280T (SR playback only)?

Many thanks.

Posted by Tony Bandiera Jr (Member # 2365) on 11-15-2004, 12:41 AM:

Brad:

It is an easy mod, you need to cut the tiny jumper marked "J801". If you look down at the top of the connector end of the card, holding the connector to your left, it is on the bottom board in line with the first of the second group of contacts ("A") (under the word "Switch" on the top cover).

IIRC, the Dolby website has the modification sheet archived.

Since you're local in LA, email me if you need more info/help!

Edit: Thanks, jhawk!! [beer]

Posted by John Hawkinson (Member # 1135) on 11-15-2004, 12:42 AM:

Brad,

This is covered in a bunch of threads, including:

Converting a Cat 280 SR to a Cat 280T SR
Dolby CP50 up grade to SR and Non sync switching proble

It's really easy.

Also, I strongly recommend following Steve Kraus's suggestion of prominently stickering the card with "modified for playback only."

--jhawk

Posted by Brad Morris (Member # 1175) on 11-22-2004, 10:53 PM:

Thanks to all for help with the mods.

Now my CP200 puts out pink noise instead of Dolby tone. Is this standard with SR cards?

Cheers-

Brad

Posted by John Hawkinson (Member # 1135) on 11-22-2004, 10:57 PM:

I can't speak to the CP200, but the SR cards use "Dolby Noise" instead of "Dolby Tone" for calibration. This is mostly irrelevant for optical sound, since you always calibrate with Dolby Tone...

--jhawk

Posted by Steve Guttag (Member # 268) on 11-23-2004, 06:05 AM:

The Dolby Tone or Dolby noise is generated by the noise reduction card so when you have an SR card installed, it outputs what it knows. The CP200 has always used the NR card to generate its tone (format 66) so when you replaced the NR card, you took its tone generator...generally only important when setting up Cat 64s made prior to the Cat 64B

Steve