dolby cat92C schematics

[Elia Orselli]

Hello!
I've searched the warehouse section, but I've found schematics only of older cat92 version. Does anyone have schematics for newer dolby cat92C magnetic preamplifier boards for MPU?
(I've raised a case in the dolby portal, but maybe somebody has these materials on hand...)

Thanks!

[Sam Chavez]

Don't believe Dolby ever published 92C drawings. I am in communication with the designer so I will get a yes/no answer right quick. It has all the features one could wish for. Is yours broken or just curious?

[Steve Guttag]

I'm not sure if I ever saw a CAT92C schematic. If we have one, it is probably on paper in either D or E size. I don't recall ever asking for it as it isn't something I ever had to troubleshoot. They just worked. The fringing compensation was a nifty feature too. It would have been nice if it worked with the high/low links were in either position. Many people moved the links to "low" in 1983 when the new recording level would drive things into oscillation (particularly before teh CAT 92-4 mods were done (and some just loaded down the head with things like 330Ω resistors.

I agree with Sam, the CAT92C was a good piece and most things one could want in a cinema mag preamp. I would have liked what Teccon put in their MPU compatible preamp...two sets of level and EQs so one could have Pre-1983 and Post-1983 settings (or "standard" and whatever walks in the door for a 1-off festival).

[Elia Orselli]

I'm mostly curious, as currently I have only cat92 boards

[Marin Zorica]

There is quite a difference between two. CAT92 is just simple pre amp with some eq and transformer input, while 92c is quite different with improved eq, input section and gain, with less noise. But still is not complicated for some troubleshooting in case you have bad one....

As for schematic, I think after CP-50/100 time Dolby newer published schematic for any newer equipment....