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Author Topic: Manual/Schematics for Dolby SA2 Surround Adaptor Robert W. Jones Film Handler Posts: 74 From: San Antonio, TX Registered: Mar 2007 posted 10-08-2007 01:06 PM                     Hello all, Looking for a manual for the SA2. If you can help me out please contact me. Need if for my screening room equipment. thanks, Rob  |  IP: Logged Bill Gabel Film God Posts: 3873 From: Technicolor / Postworks NY, USA Registered: Jan 2002 posted 10-08-2007 01:41 PM                     Look over in the manual section, there is info under the Dolby CP-100 install manual about the SA 2 Surround Adaptor.  |  IP: Logged Robert W. Jones Film Handler Posts: 74 From: San Antonio, TX Registered: Mar 2007 posted 10-08-2007 02:13 PM                     Bill, Thanks. Actually the SA2 is going on a CP100 in my screening room. What I would like to have if anyone has access to a copy is the schematics for the unit with a 116A card. The reason is I can do any repairs as need, and the schematic or service manual will provide the values and test points. Thanks for your help. Forgot about the section in the CP-100 manual for connection diagrams and setup. Rob  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 10-08-2007 02:51 PM                     Exactly what is the problem or are you trying to figure out if its in the mainframe or the 116 card? BTW: CAT 116 cards are really unacceptable for SR playback so you might want to nix the whole thing and just build in a late model CAT 150 card right into the CP-100. There's plenty of room in there and I've done this to quite a few of them. The later decoders are unbelievably superior.... the 116 is a dinosaur. The optical preamps can also be modified for proper slit loss compensation characteristics for narrow slit lens or reverse scammers. Mark  |  IP: Logged Marin Zorica Jedi Master Film Handler Posts: 671 From: Biograd na Moru, Croatia Registered: May 2003 posted 10-08-2007 04:49 PM                     quote: Mark Gulbrandsen The optical preamps can also be modified for proper slit loss compensation characteristics for narrow slit lens or reverse scammers. Can you tell me how to modify Cat 108? Because with 108 on CP50 I've reaching 12,5KHz flat with HF correction, and no isn't problem in sound head because with mine own designed preamplifier I reach 16KHz flat!!!!  |  IP: Logged Robert W. Jones Film Handler Posts: 74 From: San Antonio, TX Registered: Mar 2007 posted 10-08-2007 06:14 PM                     Mark, Good info, thanks! Not trying to diagnose a problem. Just looking for a set of schematics for future reference. Guess I'm a geek, but track down schematics for everything I have. Makes it easier to find a bad electolytic cap (which fail often in time), or a handy test point value. I do have pleanty of room in the CP100, as I'm not running 70mm. Rob  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 10-08-2007 08:00 PM                     Actually I would reccomend re-working the power supply in it... replace alll the electrolytics. Although the CP-100 power supply is one of Dolby's best designed power supplys the sheer age of the caps justifies rebuilding it. You can find the 116 schematics in the Dolby CP-50 manual here on Film Tech... the 50 used it in its early years along with I think a 146 front decoder card. There is a big problem though and that is finding the delay I.C.'s... they are VERY obsolete and were also used in the early CAT 150's. If you look around for a 150 card stick to one of the later ones. Mark  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 10-08-2007 08:38 PM                        I believe the old cp-50 front decode was a cat 110, with the 116a in the surround slot. Louis  |  IP: Logged System Notices Forum Watchdog / Soup Nazi Posts: 215 Registered: Apr 2004 posted 12-14-2008 01:20 PM                 It has been 432 days since the last post.  |  IP: Logged Stephen Furley Film God Posts: 3059 From: Coulsdon, Croydon, England Registered: May 2002 posted 12-14-2008 01:20 PM                     I'm still somewhat confused about this. The CP-50 manual says: "Note: Early CP-50's used a Cat. No. 110 (or Cat. No.82) in slot 6 to provide left, center, right decoding. Slot 7 contained a link card (Cat. No. 115) for non-surround installations, and a surround decoder (Cat. No. 116A) for installations with surround. This arrangement was superseded in April, 1979 by the Cat. No. 110L/150 system." What was the difference between the Cat. 110 and 82? I'd never heard of the 82 before, but it seems to be the Mono/Stereo Optical Module used in the CP-100. It seems that Dolby Stereo progressed quite quickly in its first few years. As far as I can make out, with the CP-100 there were five generations: 1. Three channel, without surround, using internal modules. 2. Surround channel by the addition the Cat. 92 Pentoptical module and an early model SA-2 containing a Cat. 116 surround decoder and a separate delay module, with the front channels still being handled by the modules in the CP itself. 3. As above, but using a Cat. 116a decoder, which included the delay on a daughter board. Later SA-2 units did not include the separate delay module, and therefore could not use the original Cat. 116. They also did not require mains power, as the earlier units did. 4. The SA-3 did not change the decoding, but introduced internal switching for optical/magnetic surround, in place of the external relay unit. 5. SA-4 introduced, using the Cat. 150 to decode all four channels. Have I got that about right? What was the Cat. 94 Pentoptical Module which had to be installed in the CP-100 when used with the SA-2 and 3. If a Cat. 82 and 116a between them could decode all four channels in an early CP-50, why was this extra card needed in the CP-100? Life really does seem to have become much less complicated with the introduction of the new cardset for the CP-55, and the use of the Cat. 150 for everything. What were the differences between the various generations of Cat. 150?  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 12-14-2008 02:22 PM                        The SA-2 had the 116 in it with a permanently mounted delay system. The 110 was kept in the cp-50. The Sa-2 was an option. The pentoptical module was a somewhat successful 5.0 attempt. Probably deemed too noisy on the surrounds. Combining the two channels helped a little bit on the noise problem. (Look at the drawing for early CP-50, you can see the l&r surrounds tied together.) Really great stuff for its day; not too shabby now with SR and 150 card! Early Dolby did not support surround since "the reality is on the screen." Louis  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 12-14-2008 02:48 PM                       "What was the Cat. 94 Pentoptical Module which had to be installed in the CP-100 when used with the SA-2 and 3. If a Cat. 82 and 116a between them could decode all four channels in an early CP-50, why was this extra card needed in the CP-100?" There were 3 format slots in the 100 occupied by various cards over the years. I believe the Cat. No. 82 LCR card had no way of returning the audio signal from the SA2 or SA3 surround adaptor, so the Pentoptical(sp) module was needed for this purpose. This module also decoded the LCR in a slightly different way than the 82 so one could switch from the format with the 82 and the 94 and the front channel separation was slightly different. Steve will be a long any minute now to correct me on all this. Speaking of the 100, there was the Cat. 135 that superceded the 84 to provide 10db more gain from the MPU, and the 148 card to interface with the SA4 and the 148B to interface with the SA5 and this is a topic all to itself.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-14-2008 02:57 PM                     Nope, the CP100 history pre-dates me a bit. I've had my hands on them, tuned a few but mostly observed its history from afar. The Cat 110/82 thing though...they were the same card, I'm pretty sure with the metal frame being the difference (it was in a metal frame for the CP100 for use in a format slot). Sam did fail to mention the Cat 148SR for use with the SRA-5...I bring it up here just for completeness. Steve  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 12-14-2008 08:41 PM                     the cat 82 and the 110 were the same they decoded LCR with a gain riding circuit of 3 db this was passed on to the surround decder that was outboard in the SA2  |  IP: Logged

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