quote: Ian Parfrey

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That linky, she no worky.

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quote: Tony Bandiera Jr

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One would think so, but Sony screwed up big time by doing one major thing wrong: both tracks are in the same time relationship, not offset so if one side is damaged (or at splices/missing frames) you lose the data from BOTH tracks.

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Come on Tony...if you are going to slam something, at least get your facts straight. The two tracks are indeed offset from each other! I don't have the offset handy but it is pretty easy to demonstrate. Put a piece of tape across the film (clear) and run the software and run the error test. When the tape runs through, they will not jump at the same time...I believe "P" will jump first. Since both P and S carry the center channel in an uncompressed format, the offset ensures that it takes a dual failure for a protracted period to drop center channel, ever.

While it is fun to put up the different names of SDDS...and they were mostly earned...at its end, it was a reasonably reliable system. Those that we have in operation still are tracking fine. The AFI/Silver, which often runs "previously enjoyed" prints...if they are SDDS can and do run them...with rarely, if ever an SDDS problem. Note, the AFI/Silver has the rare but coveted DFP-D2500s...known in the booth as the "best damn 8-channel VU meter for that is what they mostly do for non-SDDS films).

Steve
 

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Posted by Bernie Anderson Jr (Member # 410) on 08-17-2010, 08:23 PM:
 
my understanding, the offest between the two tracks are 19 frames difference
 

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Posted by Tony Bandiera Jr (Member # 2365) on 08-19-2010, 01:01 PM:
 
Steve/Bernie:

I stand corrected, thank you both. My information came from a former AMC tech, who we all know had tons of SDDS units.

Come to think of it, he wasn't the sharpest tool in the tool chest...

I still stand by my remark that SDDS has the worst track location and reliability.
 

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Posted by Monte L Fullmer (Member # 2797) on 08-19-2010, 01:13 PM:
 
My understanding that a new SDDS track would only last a week or two. Afterwards, the error counts would begin to climb on the soundtrack side before the other one would begin to kick in.

Also, didn't Dolby have a fit with this and threatened lawsuit for copyright infringement since it basically had the same form of track layout and read method as did the Dolby?
 

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Posted by Tony Bandiera Jr (Member # 2365) on 08-19-2010, 01:21 PM:
 
I don't know about lawsuits, but I was told (if this is true or not I have no idea but it makes a great story) that when the studios ordered all the players to make sure they could exist on the same print (no mulit-inventory like in the past), when Dolby had to send samples of its track to Sony they replaced the "double-D" logo with a picture of Ray Dolby giving them the finger.

Sony sent the sample back with a picture that was supposedly the head of Sony mooning them.

This exchange allegedly went on for the duration of the track development process.
 

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Posted by Marin Zorica (Member # 1716) on 08-19-2010, 03:49 PM:
 
Hmmm....when talking about last of SDDS track, I have some traillers and print, both have SDDS and Dolby D, few of them even can't read more than F on Dolby, but when played on SDDS it work's even without any drop.....but, this can't be precise factor, as prints can be damaged on different area.

And, Sony was first to use visible red light, as will give more immune reading due scratches and so if I'm correct?
 

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Posted by John Hawkinson (Member # 1135) on 08-19-2010, 07:48 PM:
 
I think a lot depends on how your prints are cared for. Because of its proximity to the edge, SDDS is extremely suceptible to dirt, perhaps more so than it is to scratching (which SRD is). But dirt can be removed and prevented.

So if you run a very clean booth or use filmguard or various other factors, SDDS can have extremely good performance.

Also, anecdotally, we have heard here on Film-Tech that the labs are much better at churning out SDDS prints now than they were 10 years ago, which is somewhat ironic given the state of things...

--jhawk
 

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Posted by Mark Gulbrandsen (Member # 72) on 08-20-2010, 03:41 AM:
 

quote: Tony Bandiera Jr

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I don't know about lawsuits, but I was told (if this is true or not I have no idea but it makes a great story) that when the studios ordered all the players to make sure they could exist on the same print (no mulit-inventory like in the past), when Dolby had to send samples of its track to Sony they replaced the "double-D" logo with a picture of Ray Dolby giving them the finger.

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quote: Peter Castle

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Dolby tracks were often bad from day 1

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quote: John Wilson

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Okay, the definative test for the efficiency of FilmGuard has ended here. After 11 weeks and 254 passes, we have finally finished with the print.
It leaves in 'as new if not better' condition. Not a single speck of dirt, dust or markings of any kind and with an SRD error rating hitting 0. in some parts of the film on a basement reader.

NO kidding, Michael Barry witnessed this phenomenon

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quote: Michael Barry

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Indeed, I was there! It looked better after all those runs than many films I've turned up to at (insert major megaplex here) on opening weekend! It didn't just look good for the age - it just looked incredible in an absolute sense. And yes, the Dolby Digital error rate was on 0 when I looked

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quote: Peter Castle

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Whether the print is brand new or four weeks old, why is (SDDS) fine but the Dolby Digital is already dropping out.

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I think his SRD readers are out of adjustment, or as Monte suggested he has bad trap bands or other parts that are damaging the SRD tracks.

Either way a service call by a competent tech is in order for his theatre.
 

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Posted by Louis Bornwasser (Member # 3063) on 08-20-2010, 03:50 PM:
 
I concur. (Stop using the computer and start using the scope for alignment. This is a sure sign of misalignment.) Louis
 

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Posted by Joe Redifer (Member # 3) on 08-20-2010, 04:36 PM:
 
My prints rarely change Dolby Digital error rates over their lives. Sometimes it'll even get slightly better over time due to cleaning. I've never gotten a used print with bad Dolby Digital, either.
 

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Posted by Mike Blakesley (Member # 26) on 08-20-2010, 05:02 PM:
 
After using Dolby Digital for about 4 years, we only had 1 print that would not play in that format. But it was due to sprocket damage from a previous use. Other than that, we had 100% reliability on all prints including used ones.
 

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Posted by Joe Redifer (Member # 3) on 08-20-2010, 08:02 PM:
 
The only time I've had unplayable Dolby Digital is on a few Indian prints where the blocks were printed "out of frame" (for lack of a better term). Usually in that case I'll just play in DTS as they've always offered both formats when they fubar the DD.
 

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Posted by Bill Duelly (Member # 3612) on 08-20-2010, 10:40 PM:
 
I have a 3000 and I think it does a great job with analog and I love the SDDS... when I don't have a damaged print. Then the kicking back and forth between digital BU as well as down to analog is rather annoying. The initial problem I had was finding the right tension setting as I generally run from 6000' reels. Too tight and I would get too many errors on SDDS tracks.
 

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Posted by Mark Gulbrandsen (Member # 72) on 08-21-2010, 06:10 AM:
 
Bill.... The 3000 does a great job with SDDS and is quite reliable in that aspect... It also makes a great D-Cinema processor. But compare it side by side to a CP-650 or better yet a Panastereo CSP-1200 if you can find one and you're in for a big analog disappointment! A USL JS Series with it's SR card actually does a more credible job at decoding SR than the 3000 does.

Louis... Use both the scope AND the laptop. The laptop offers pertinent info that the scope does not.

Mark
 

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Posted by Marin Zorica (Member # 1716) on 08-21-2010, 12:07 PM:
 
Talking about SR on Sony 3000 and rest would be long here, but thing that hates me on dolby units, also CP650 is that analog multichannel inputs are unbalanced!! Again, on all sony equipment is balanced, which again gave it great for using on D cinema, or some multi house which has more than one audio source.
 

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Posted by Tony Bandiera Jr (Member # 2365) on 08-21-2010, 02:51 PM:
 
Marin, balanced inputs/outputs don't offer any real advantage in a typical cinema installation. Unless the cable length gets much over 50' you are NOT gonna have the noise and signal loss issues that balanced lines are supposedly correcting for.

At UC Irvine in my one room the lines run unbalanced in conduits to the amps backstage, passing through a patchbay at a second rack, for a distance of well over 125 feet and I do not have any noise or signal loss issues. They were fed by first a CP-65 and now a CP-650 with no noise or other problems. (Caused by the unbalanced lines that is. Now the tie-in from the classroom system is another issue and it is causing problems.)

Depending on the amplifier, you either tie the shield to the (-) pin at one end or you can do as I have done, which is connect the shield at the amp end ONLY and float it at the processor end. (Depending on the amp's input design though my method does result in a 3-6dB reduction in level.) Noise though has never been an issue with my method..so far. I am sure I will eventually run into the exception to it.
 

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Posted by Brad Miller (Member # 2) on 08-21-2010, 04:10 PM:
 
So am I the only person here who thinks the DFP3000 is awful with optical sound???

The DFP3000 and DFP2000's EQ are also awful in my opinion with hf deficient pn. The only way I will use a Sony product is if I flatten the EQ and do it elsewhere.
 

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Posted by Steve Guttag (Member # 268) on 08-21-2010, 05:25 PM:
 
I'm not a fan of the 3000's A-chain and their NRII doesn't cut it...haven't played with NR 1 enough to determine if it is passable for "A".

As for their EQ...it actually is pretty decent...their Pink Noise is tainted and will cause one to overly brighten a signal. However, knowing that...one can achieve a good EQ with it and it can out-sound other film based digital formats. I don't agree that one need go to another EQ system as the other system may be the limiting factor.

-Steve
 

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Posted by Marin Zorica (Member # 1716) on 08-22-2010, 01:05 PM:
 
I prefer balanced inputs and outputs mostly (and probably) because I do work around some festivals and special venue, where we need to feed couple of sources to unit, then Sony units works as master, and mostly BETA and other systems have balanced outputs with +4dBu reference, which is better to patch in balanced input than unbalanced.

Brad, you mentioned couple times Sony B chain, why you don't find EQ good? Is it because of EQ itself, or because internal PN generator?

On A chain, I think is pretty okay on 3000, NR1&2 are different thing, even this summer I installed one 3000 in open air for festival, I was relly suprised how did sound good. Even today on my opinion many optical mixes are bad and pretty distorted, as we know in postproduction probably guys don't give lot of time about analog sound. I remember one time talking with guy who did sound mix, it was first run of movie and I was called to do A & B chain, sound was okay, even I didn't like it much, this cinema had analog only, but movie was mixed in digital also, when I asked a guy do they make test and run analog mix for itself, because there is about 10dB difference minimum, he said they just compress it a bit and that is all, doing that I'm not suprised why sometimes SR sounds distorted, specialy when after that I run some print from 1988 and find that mix sound great.
 

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Posted by John Hawkinson (Member # 1135) on 08-22-2010, 07:51 PM:
 
Tony writes, "depending on the amplifier, you either tie the shield to the (-) pin at one end or you can do as I have done, which is connect the shield at the amp end ONLY and float it at the processor end. (Depending on the amp's input design though my method does result in a 3-6dB reduction in level.) "
(emphasis mine).

Huh?????????

--jhawk
 

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Posted by Tony Bandiera Jr (Member # 2365) on 08-22-2010, 08:36 PM:
 
John,

There were certain amplifiers (I believe it was Peavey CS series and QSC Series Ones) where my connection method (a "psuedo=balanced" connection) was supposed to have resulted in less gain than when the amp's shields and (-)terminals were tied together.

The QSC MXa Series manual here on the site says something about it on page #6 of the pdf file. They state:

"For use with unbalanced signals, connect the unused terminal to ground to avoid a reduction in gain caused by a floating input; use a two-conductor (tip-sleeve)plug, or connect a jumper between the inverting input terminals on the barrier strip and their adjacent ground terminal."

In the real world usage I have (so far) never had a problem if I did not install that jumper.

IIRC it was in wither the Peavey or Series One manual that they stated an actual dB range.
 

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Posted by Scott Norwood (Member # 30) on 08-22-2010, 09:08 PM:
 
Given the choice of balanced outputs or unbalanced outputs, wouldn't everyone choose balanced? That at least gives the option of putting the amp rack behind the screen (or even using powered speakers in a temporary setup) without needing extra transformers. It can also make life easier when fixing ground loop issues.

Balanced non-sync inputs would also be a good idea, especially for multiplexes. It is not uncommon for a multiplex to use a single CD player with a distribution amp for non-sync music in all houses, and doing so properly would require transformers at each end (cumbersome and expensive).

I actually had this discussion recently, regarding why it would be a bad idea to run unbalanced lines for non-sync throughout a multiplex.

Pretty much every other piece of professional sound equipment has balanced I/O; why shouldn't the same be true of cinema processors?
 

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Posted by Monte L Fullmer (Member # 2797) on 08-22-2010, 10:51 PM:
 
Interesting discussion here, for I also have a question on a theatre that called me for a sound issue while in optical where the optical sound has the sound of a transitor radio (like the center channel has the LF turned down), and they also have SDDS for the digital sound:

When in SDDS, it does sound good.. all 6 channels are doing good.

They have unmodified CP55's for their optical for 4channel playback. (??? How would that work - having 4channel for one process, yet can do 6 with another??)

The have CE-M100's for their monitors.

leads for the monitor's input are tapped from the processor's outputs to the amplifiers (ASHLY's) in which the leads to the amplifiers are connected in the balanced fashion (plus, minus, shield)

Yet, the plus leads are running up to the monitor amp are heading up to the plus connections, yet the sheild is floating (unconnected, or like a drain of sorts).

I told the owner to disconnect the leads from the rear of the monitor amp and his sound return to normal.

How should his setup been connected so the house sound would not have been affected and can still use his monitor amp?

thx-monte
 

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Posted by John Hawkinson (Member # 1135) on 08-22-2010, 11:33 PM:
 
Err...OK, Tony, your case is if you connect your unbalanced signal to ground/+ and your amp is expecting to see voltage between -/+ not ground/+, then it might think your voltage is half as much as it really is? Ummm...I guess. I think there's something wrong with this. If you only hook up two wires (i.e. don't connect the shield), don't you generally tie the ground of your unbalanced cable to the signal - input anyhow?

Scott: basically lots of people don't have the choice. Historically Dolby processors only offered unbalanced outputs. So you had to jump through hoops to convert to balanced.

I also think the risks/dangers of unbalanced are probably overstated. A lot of people have no problems. And if your amplifier has an input transformer, then does it even matter at all? (That said, we have transformers.)

--jhawk
 

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Posted by Tony Bandiera Jr (Member # 2365) on 08-23-2010, 12:12 AM:
 
John, Not my case and don't try to make it into mine. I'm telling y'all what those makers have said (See the MXa manual) about their inputs' requirements. I don't know precisely why they claim that and I don't care. As long as my systems work without noise and gain issues it's all good.

You are correct, in that I use the (-) for my unbalanced signal ground, for example, coming from a CP-65, using Belden 8451/9451, at the CP-65 end, red goes to Center channel, black goes to "E" (earth terminal in Dolby-speak) and the shield is not connected. At the amp, red goes to (+), black goes to (-), and the shield goes to the amp's ground terminal.

Now according to the MXa manual, I am supposed to connect the (-) and the ground together at the amp end.

I think if I were to connect my black wire in the example I gave above to the gnd at the amp instead of the (-), I'm willing to bet there would be problems.

To whit:

quote: Monte L Fullmer

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....The have CE-M100's for their monitors.

leads for the monitor's input are tapped from the processor's outputs to the amplifiers (ASHLY's) in which the leads to the amplifiers are connected in the balanced fashion (plus, minus, shield)

Yet, the plus leads are running up to the monitor amp are heading up to the plus connections, yet the sheild is floating (unconnected, or like a drain of sorts).

I told the owner to disconnect the leads from the rear of the monitor amp and his sound return to normal.

How should his setup been connected so the house sound would not have been affected and can still use his monitor amp?

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Monte, more important is how is the output of the CP-55 tied in to the system? IIRC when feeding the outputs of the Dolby into the balanced inputs of a Sony SDDS you would connect the channel (+) outputs to pin 2 of the xlr, and tie pins 1 (gnd or shield) and 3 (-) together. If you don't tie the pins 3 and 1 together with unbalanced sources you can get the thin sound you describe. (Try lifting pin 3 or 2 of a microphone and you'll get the same effect. )

If the SDDS and the CP-55's outputs are "piggybacked" onto the amp's outputs then that is the problem. The Dolby should feed through the SDDS system. (Another thing I never liked about the whole SDDS debacle..you have to feed your optical processor through the SDDS to ensure reliable fallback..)

The connections to the CE monitor are pretty much normal, I have seen where all the processor sides have only the (+) leads connected and one of the speaker side (-) is used as a return. (My experience with CE MS-100 is that it seems to work best when I connect only one of the processor side (-) to the monitor and do not connect any of the speaker side (-) to the monitor.)

Bear in mind that the CE MS-100 sometimes fails and loads down the processor outputs.
 

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Posted by Monte L Fullmer (Member # 2797) on 08-23-2010, 01:15 PM:
 
Thx Tony for the help. No, they do have the optical feed from the Dolby going into the SONY as you described, thus I do believe that it was how the monitor was connected. But I'll check to see how the XLR is connected for unbalanced signals.. Monte
 

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Posted by Dominic Espinosa (Member # 2122) on 08-23-2010, 01:55 PM:
 
This has little to do with the topic but is an amusing anecdote nonetheless.

I recently visited the US assembly line for the 4K projectors, it's in my backyard actually.
They have an SDDS unit set up on a test-bed in the lab but no one, at least none of the folks on the tour including a veteran trainer, had any idea what the thing was.

When I explained the history in brief you could see light bulbs going on. Sort of like the Sony guys going "so THIS is why theater people don't like us..."
 

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Posted by Tony Bandiera Jr (Member # 2365) on 08-23-2010, 05:43 PM:
 
You're welcome Monte. Let us know what you find...

Dominic, That is funny and sad at the same time. But not surprising considering their track record in the cinema (and according to Mark G., the broadcast) business.
 

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Posted by Frank Angel (Member # 248) on 08-23-2010, 05:47 PM:
 
Re: how to deal with vexing ground loops that can't be resolved by the usual apparent methods. From the RCA Technical Service protocol --

1) Turn on the system so you hear the offending hum

2) start at the signal origin point

3) if the sheild not connected to ground, connect it

4) if the offending hum gets louder, disconnect it

5) if the offending hum gets lower, solder it

Repeat until you get to the amplifer

If none of this helps, tell the exhibitor he needs to call in an Ampex Service technician.
 

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