Film-Tech Forum ARCHIVE: "Fuzzy" or "Scuzzy" drive?

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Posted by Brent Francis (Member # 5008) on 03-05-2019, 11:43 AM:

Hi. Old ex-projectionist with old/former tech question. Trying to remember details of a sound system (we called it "Fuzzy" drive),used at the start of digital sound. When the film started running, the projector was interlocked with an audio card (I think?) that would send a repeating electronic pulse to the audio system, keeping it in sync. My nephew's curious about this for a school project & I can't seem to find anything on the net. All I remember is that it broke down half the time!
Thanks.

Posted by Martin McCaffery (Member # 37) on 03-05-2019, 04:35 PM:

Do you mean a SCSI drive? Which were called "scuzzy drives"
Wikipedia

Posted by Monte L Fullmer (Member # 2797) on 03-05-2019, 05:09 PM:

Sync with audio to begin the digital audio .. sounds like DTS where it was a new version of "sound on disc" during the talkies era.

..where the disc would sync with the frame of the feature (even though with DTS, there were more processes needed to make this work.

IMAX 15/70 used Sonics where the frame would be in alignment with a roller where it would send pulses to the Sonics system so audio would be in sync with the image.

Monte

Posted by Carsten Kurz (Member # 5396) on 03-05-2019, 05:19 PM:

Around the early nineties, there were a few prototype digital film sound systems around using a separate medium, synced to the filmstrip via a so called timecode. Of these systems, only DTS had a considerable market share later.
DTS indeed used SCSI CD-drives. You can find some documents about these systems in the film-tech warehouse download section unter Manuals - > Sound Equipment. Look for DTS 6 or DTS 6D. These manuals also contain a short introduction to the system. Wikipedia has an article about DTS, but, over time, DTS created many different systems and it may be complicated for you to understand the differences. You may read unter 'History' and 'Theatrical use'.

- Carsten

Posted by Armand Daiguillon (Member # 10334) on 03-05-2019, 05:23 PM:

Yeah, you're definitely thinking of DTS. It was one of the 3 digital sound formats of the time (least popular) the others were SDDS (sony) and Dolby Digital.
DTS used separate discs for the audio - these followed a time code on the film. It differed from the rest in that the digital audio was not on the print - but on separate discs.
SDDS and Dolby had the digital sound on the print itself. In SDDS case the digital info was poorly placed and often wore out over time. I remember going into the booth and seeing all the SDDs processors on bypass with any older prints ....but yeah if you need spec info just look up DTS Digital Sound.

Posted by Monte L Fullmer (Member # 2797) on 03-05-2019, 05:58 PM:

Then, you had the obscure 70mm only CDS.

Pixel audio track printed on the film and no analog backup.

The DTS-6 and DTS-6D drives were SCSI attached to a SX25 motherboard via SCSI controller card.

Posted by Marcel Birgelen (Member # 6801) on 03-05-2019, 06:12 PM:

Fuzzy drive sounds like a drive mechanism involving fuzzy logic...

CDS was also available on 35mm, but it indeed replaced the analog audio tracks. It used awkward delta modulation on PCM tracks. I've never really heard the system in action, but I suppose the delta modulation must have sounded far worse than what DTS and Dolby had to offer.

Anyway, it stored the audio on the primary playback medium, so there was no real reason to sync between both systems.

IMAX's digital sound system for film was based on the DTS system, also using SMPTE time code to sync the sound playback system to film. The difference was, that they used uncompressed audio, while the standard DTS format used a compression similar to Dolby's AC3 (MP3) compression.

quote: Armand Daiguillon
Yeah, you're definitely thinking of DTS. It was one of the 3 digital sound formats of the time (least popular) the others were SDDS (sony) and Dolby Digital.

DTS didn't really involve a soundcard. Although you could call the timecode signal an "audio signal", the DTS decoder could interpret the timecode from the reader directly.

Also, I don't remember DTS to be a system that broke half of the time. It was, all in all, a pretty reliable playback system.

Posted by Brent Francis (Member # 5008) on 03-06-2019, 02:46 PM:

Thanks for all the info folks. We had DTS/SDDS/E-I-E-I-O and all that. But this was like trying to send the pulse signal to a separate audio player in another room that was patched into our speakers. It screwed up so often one gerbil, oops, I mean client, said "somebody's gonna get fired" if it didn't work. Thanks heavens it got better later!

Cheers

Posted by Scott Norwood (Member # 30) on 03-06-2019, 02:55 PM:

Was this something for postproduction or preview screenings? There are a few different devices that work like dubbers for synchronizing, say, a DA-88 tape or sound file on a hard disk to film. Tascam makes/made DA-88 and Fostex makes/made a hard disk recorder for that purpose. I have no idea if these were reliable or not. My only experience with such screenings is with 35mm dubbers (which seemed to work fine).

I can't imagine anything as unreliable as the one mentioned here ever being used for mainstream releases in regular cinemas.

Posted by Brent Francis (Member # 5008) on 03-06-2019, 03:06 PM:

DA-88 maybe? Sounds familiar Anyway. Yes, I worked at a film lab where we did answer prints, previews & such. Thanks,

Posted by Sean McKinnon (Member # 612) on 03-06-2019, 04:20 PM:

#1. CDS wasnt 70mm only

#2. I think you are thinking of an unmarried interlock using a bi-phase shaft encoder either with a mag dubber or some other type of audio player.

Posted by Mark Gulbrandsen (Member # 72) on 03-06-2019, 07:44 PM:

Very early DTS Large Format players did use SCSI drives.

Mark

Posted by Marcel Birgelen (Member # 6801) on 03-08-2019, 05:37 AM:

E-I-E-I-O?

Like in Old MacDonald Had a Farm?

Posted by Dave Macaulay (Member # 813) on 03-08-2019, 09:52 AM:

Early IMAX® digital sound was not DTS. In 1987 or so IMAX first commissioned a 6 channel CD based system that used three professional CD players (Tascam?) and normal Red Book CDs: this managed to get the players synced with sample accuracy, but the system had reliability issues.
Then Sonics Associates produced a similar 3 CD system that was widely used.
The sync source was a biphase shaft encoder on the projector: once the film was threaded with START in the aperture, a sync lock button is pressed - just like with the 35mm 6 channel mag dubbers IMAX used. IMAX 15/70 projectors are still manually synced to their sound player this way.

Posted by Brent Francis (Member # 5008) on 03-08-2019, 09:59 AM:

Hi again. Sorry 4 the delay. After it left our end, I had no clue since the audio dept. was separate from us & we didn't communicate much. All I really know is that it wasn't mag track because we had interlock for that.
Thanks.

Posted by Gordon McLeod (Member # 33) on 03-08-2019, 11:27 AM:

During its long life span DTS remained a SCSI based system even after they started using IDE DVD drives each had a daughter board that converted it to SCSI
There was also a early system that used laser disks with the time code printed on the outer edge of the film but it never caught on
Overall DTS was a stable system that was very reliable