Film-Tech Forum ARCHIVE: Optical Sound Troubleshooting Help

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Posted by Martin McCaffery (Member # 37) on 07-20-2009, 01:03 PM:

SH1000 soundheads, CP650, Kelmar basement readers, duel projector

Problem on single projector

Digital sound is fine. Optical is all over the place from muddy to garbled with perfectly fine parts in the same scenes. Discovered it this weekend while showing the Breakfast Club. Very new print. Dolby A. Going to mono masks, but doesn't get rid of the problems

Digital trailers are fine on that machine in digital, same problems in A and SR.

Brass in the music totally falls apart. Molly Ringwald sounds like she's gargling, but only in the upper register. Some scenes sound like they are in a barrel.

Quick checks don't yield any results. Buzz track fine. Dolby 69P slit loss shows no problems.

Where to look next?

Posted by Tony Bandiera Jr (Member # 2365) on 07-20-2009, 01:19 PM:

What is the error rate on the digital? Is digital a basement reader as well? If the error rate on digital has gotten higher, then it's a mechanical issue.

In order of probability:

Problem sounds like an issue with either the lateral guide roller assembly, which could be not closing properly (especially if the symptoms came on suddenly) as the lever to open it can twist on the shaft so that the latch pawl in the back won't seat properly.

The lateral guide rollers could be stuck (remember that one flange should be able to move slightly on the shaft to allow for splices and worn film).

The roller on the lateral guide that touches the film may have dirt build-up or a piece of tape or film stuck on it, or may be worn out.

The bearings on the sound drum may be going bad.

The flywheel on the sound drum shaft may be loose or rubbing on something.

Could also just be a bad print. Try another film on the same machine if possible.

Finally it could be an impending electronic or power supply failure of the Kelmar basement reader. (Least likely.)

Those are the things to check out.

Posted by Demetris Thoupis (Member # 833) on 07-20-2009, 02:22 PM:

Ermm sorry but he says that he has a problem in optical sound not Digital! Is the sound drum spinning fine or is it having a hard time spining?

Posted by Martin McCaffery (Member # 37) on 07-20-2009, 02:36 PM:

Sound drum.

The screw holding the flywheel to the shaft fell out, so the drum was slipping.

Now have to find a new screw and get it in there.

Anyone ever have that screw come loose on its own before?

Posted by Tony Bandiera Jr (Member # 2365) on 07-20-2009, 04:28 PM:

quote: Demetris Thoupis
Ermm sorry but he says that he has a problem in optical sound not Digital! Is the sound drum spinning fine or is it having a hard time spining?

Errm sorry to you too sir, IF the digital is a basement reader it WILL be affected by the sound drum issue..by showing increased error rates. As long as the error rates stay low enough, yes digital will still play without major audible issues. Try it on any of your machines, use your finger to drag on the scanning drum of any reader and watch the error rate shoot up.

Martin, if memory serves that screw is an 8/32 thread. You can temporarily substitute any 8/32 screw long enough to pass through the flywheel and shaft. I think one that's 1 1/2 inches long will do the trick.

I may also have the proper screws in my stock, if you can't find or get one send me a PM and I can send the part to you.

Posted by Mark Gulbrandsen (Member # 72) on 07-20-2009, 07:07 PM:

quote: Martin McCaffery
Molly Ringwald sounds like she's gargling

Thats nothing new she always did sound that way!

I bet you have oil in the analog sound lens assy...

Posted by Monte L Fullmer (Member # 2797) on 07-20-2009, 09:37 PM:

quote: Tony Bandiera Jr
8/32 screw long enough to pass through the flywheel and shaft. I think one that's 1 1/2 inches long will do the trick.

On that scanner drum shaft, there should be a thrust washer inbetween the flywheel and scanner drum bearing.

Have some one hold the scanner drum in while you do the flywheel -it's not too fun trying to put on one of those fluid filled flywheels to get the holes aligned up when the scanner drum shaft moves in on yas.

I just did a main drive seal on a XL/SH1000 setup and if you don't think that was fun getting that flywheel back on by myself when I couldn't reach around to hold the scanner drum in too well..

I've seen so may regular 8x32" screws used that weren't of stock used in holding down the flywheels on these things ...

-Monte

Posted by Mark Gulbrandsen (Member # 72) on 07-20-2009, 10:10 PM:

quote: Monte L Fullmer
I just did a main drive seal on a XL/SH1000 setup and if you don't think that was fun getting that flywheel back on by myself when I couldn't reach around to hold the scanner drum in too well..

When you come down to BYU I have a good trick I'll share with you that makes putting the flywheel back on a snap!!

Mark

Posted by Monte L Fullmer (Member # 2797) on 07-20-2009, 10:15 PM:

Sounds like a plan - I could stood to learn some new tricks with Simplex units and sound stuff in general ... thx - Monte

Posted by Martin McCaffery (Member # 37) on 07-21-2009, 08:44 AM:

Monte, I know what you mean about getting the flywheel back together. Yesterday I discovered a way to do it in under a minute. The secret is an extendable pickup magnet (one of those things that looks like an car antenna with a magnet on the end).

Hold the screw with the magnet, push the flywheel until the holes line up, insert screw into the proper hole, let go of the flywheel and there will be enough pressure to pull the screw off of the magnet.

Note to people doing this for the first time, there is a big hole and small hole. Put the screw into the big hole and push thru. The screw is screwed into the small hole on the other side.

Don't know if this was Mark's trick, but it worked for me.

Posted by Louis Bornwasser (Member # 3063) on 07-21-2009, 10:22 AM:

Martin; I just reach around with the projector door closed. Louis

Posted by Martin McCaffery (Member # 37) on 07-21-2009, 11:25 AM:

You clearly have better eyesight than I [Wink]

Posted by Demetris Thoupis (Member # 833) on 07-21-2009, 02:09 PM:

quote: Martin McCaffery
Digital sound is fine.

Sorry Tony but which part of that did you not understand?

Posted by Tony Bandiera Jr (Member # 2365) on 07-21-2009, 04:45 PM:

Demetris, what part of the following did YOU not understand?:

quote:
IF the digital is a basement reader it WILL be affected by the sound drum issue..by showing increased error rates. As long as the error rates stay low enough, yes digital will still play without major audible issues. Try it on any of your machines, use your finger to drag on the scanning drum of any reader and watch the error rate shoot up.

Because even with flutter that would be very bad in analog, the digital WILL still play acceptably, up to a point.

That is why I asked if the digital had a higher-than-normal error rate.

Like this:

quote:
What is the error rate on the digital? Is digital a basement reader as well? If the error rate on digital has gotten higher, then it's a mechanical issue.

Which, by the way, if you read Martin's posts, you will see it WAS a mechanical issue.

Please try to read ALL posts carefully before coming back with smart-ass remarks.

I have over 26 years experience as a service tech and one of the many things I have learned over the years is to get ALL the facts , even if it doesn't seem to be related to the problem at hand. It saves a lot of time.

Posted by Monte L Fullmer (Member # 2797) on 07-21-2009, 05:45 PM:

May I add a side comment on this issue on SR-D above: I tend a small 4plex that has SR-D in one house. Yet, they have a BACP penthouse reader.

They off and on experience occasional digital error rate problems were it's close to fail.

I look over their system and notice something that could be an attribute to this above mentioned condition that they presented to me: On their 5star head, they're using an induction motor, not a sync motor..

I told the owners that the error rate issue could be coming from having the induction motor driving this setup since they do have slight voltage fluctuations within the building. And with voltage fluctuations will cause film speed variances across the reader which the end results is the higher error rate to an occasional dropout in digital all together.

I left it up to them on what they want to do ...

-Monte

Posted by Demetris Thoupis (Member # 833) on 07-22-2009, 12:34 AM:

If a sound drum is not spinning correctly definately the Digital will not playback most probably at all. Martin clearly said that Digital is fine so most probably he was using a Penthouse reader. As far as the garbled sound I saw this effect 2 times and both times was the sounddrum not spinning correctly.
Demetris

Posted by Monte L Fullmer (Member # 2797) on 07-22-2009, 03:18 AM:

Don't you hate it when flywheels holddown screws - both bolt and allen set love to come loose...?

Posted by Martin McCaffery (Member # 37) on 07-22-2009, 08:52 AM:

FWI at this point. Basement red reader for both optical and digital. The digital continued to read properly, at least in the short term trailer testing. The problem with using trailers for tests, they all have different failure rates.

Contributing to the problem was a crappy track on The Breakfast Club. After getting rid of the gross problems caused by the flywheel, there was still high sibilance and distortion, just not as much. Sounded like an unfocused exciter lamp on both machines. Beverly Hills Cop started last night and it was crystal clear, with no adjustments made.

Nonetheless, all suggestions were helpful. Thanks

Posted by Kenneth Wuepper (Member # 1174) on 07-22-2009, 11:27 AM:

Martin,

What kind of printing was used for the analog track on The Breakfast Club? If it was high magenta it might have given distortion from the red reader. Also it might have been CCIR equalized and that is brighter than SMPTE.

KEN

Posted by Martin McCaffery (Member # 37) on 07-22-2009, 11:55 AM:

Ken, the print's gone, so I can't check. Looked like a plain black Dolby track the bit I looked at (I wasn't the one inspecting the print).

Judging from the soft, mushy look of the picture, and the amount of negative dirt, I lean towards just a sloppy printing job.

Posted by John Wilson (Member # 269) on 07-22-2009, 04:59 PM:

quote: Martin McCaffery
The Breakfast Club. After getting rid of the gross problems caused by the flywheel, there was still high sibilance and distortion, just not as much. Sounded like an unfocused exciter lamp on both machines. Beverly Hills Cop started last night and it was crystal clear, with no adjustments made

Hey Martin,

What model Time Machine are you using now? [Wink]

Posted by Martin McCaffery (Member # 37) on 07-22-2009, 09:53 PM:

A Simplex XL [Wink]

Posted by Tony Bandiera Jr (Member # 2365) on 07-22-2009, 10:58 PM:

quote: Demetris Thoupis
If a sound drum is not spinning correctly definately the Digital will not playback most probably at all. Martin clearly said that Digital is fine so most probably he was using a Penthouse reader.

Sigh. It turns out it IS a Basement reader and it was playing digital OK, but most likely with higher error rates. Martin admitted he wasn't sure if the error rates were higher or not.

A key to good troubleshooting is to look at ALL possible cause/effect, even if it isn't at first glance directly related to the problem at hand.

If you want to become a better projectionist/technician, you really need to listen to what other people have to say and be willing to admit it when you're wrong.

In all my years I am STILL learning new things and when I'm wrong, I'm the first to admit it, whether here on the forum or to a client. I get a LOT of referrals and good customer feedback because I keep open-minded.

Example of unusual cause/effect: Customer had a CP-200 that would randomly switch to Format preset "D" (set for non/sync in that case) with no thumps or other drop-outs in the sound. After disconnecting the automation connection (rules out automation issue), pulling and re-seating ALL of the cards (rules out bad connection at the cards), pulling, inspecting and re-seating the power supply DC bundle (rules out bad Molex connections/loose pins) the problem persisted. What I eventually found, was that in the rat's nest of power cords (ALL the plug ends were cut off and tied in by a terminal strip) that the neutral on the CP-200 power supply cord's screw was loose. Tightened up the screw and no more problems. The loose connection would interrupt the power just long enough to fool the logic circuits into thinking the processor was powering up, but not long enough to make a thump in the sound. I found the bad connection when I kicked the rack in frustration. [Big Grin]

I can look back and laugh at that service call now, though it wasn't so funny then. But it's unusual stuff like that that keeps me on my toes and keeps the job interesting.

Posted by Mark Gulbrandsen (Member # 72) on 07-22-2009, 11:09 PM:

I'm still thinking oil in the analog sound optics... I've seen this happen on both C.E. and Kelmar basements. Sounds very murkey... no high end and lots-o-distortion. Note that on both companies basement readers the analog lens points slightly up to better accept any oil drips... of which there are usually more then plenty available from X-Ls. If digital reads fine and analog sounds like hell just run a pink noise loop and use the spectrum analyzer feature on the processor and you'll see it right away...

Mark

Posted by Demetris Thoupis (Member # 833) on 07-23-2009, 12:34 AM:

quote: Tony Bandiera Jr
A key to good troubleshooting is to look at ALL possible cause/effect, even if it isn't at first glance directly related to the problem at hand.

If you want to become a better projectionist/technician, you really need to listen to what other people have to say and be willing to admit it when you're wrong.

Hmm so when there is no sound in the auditorium I need to take the ladder and check first if a speaker cable is out, then go back to the amplifiers to see if the cable is out, then see if the signal cable from the amps to the processor is damaged and THEN check if they are off!! Hmm does not sound like a good advice to me. Sorry but his point clearly mentioned analogue sound. Someone saying that analogue has a problem means that the analogue has a problem! Why start checking anything else besides obvious reasons. In any case it WAS the sound drum as I suggested in my very first post so sorry sir but I was not wrong regardless of the fact that he had a basement reader for digital.

Posted by Monte L Fullmer (Member # 2797) on 07-23-2009, 04:26 AM:

Big simple question for Martin: Now that you don't have that one questionable print in that house, how is the sound in optical in that house now?

Cleaned up or still iffy?

-Monte

Posted by Martin McCaffery (Member # 37) on 07-23-2009, 08:39 AM:

Optical cleaned up when we switched from Breakfast Club to Beverly Hills Cop.

Posted by Louis Bornwasser (Member # 3063) on 07-23-2009, 01:05 PM:

I LIKE that kind of fix!! Louis

Posted by Gordon McLeod (Member # 33) on 07-23-2009, 03:51 PM:

I think two people need to take a valium
they are many methods of troubleshooting and often the equipment type or common method of installation in a given region needs to be taken into account

Posted by John Wilson (Member # 269) on 07-23-2009, 04:01 PM:

quote: Martin McCaffery
Optical cleaned up when we switched from Breakfast Club to Beverly Hills Cop.

Eddie cleaned up Molly? [Eek!]

Posted by Scott Christopher (Member # 834) on 07-25-2009, 12:21 AM:

Sorry Demetris, but Tony is right. Everything he suggested I would have checked aswell.

Yes you did suggest the sound drum, but Tony mentioned it in his post before you which would indicate you didn't read the entire post.

Posted by Demetris Thoupis (Member # 833) on 07-25-2009, 01:14 AM:

Scott, I did not say that Tony was wrong. Read all my posts and you will see. I have read a lot of Tonys' posts in other threads as well and they are very well detailed posts. What I was simply saying and nobody seems to have understood is that when a client says that something is working fine your should not start checking the things that are working fine!

quote: Martin McCaffery
Digital sound is fine.

How much clearer shall it be for a technician to NOT start looking for Digital errors. From Martin's posts it was clear that is was something mechanically error, lateral guide roller not sitting correctly as Tony suggested e.t.c. But because I've seen this effect 2 times I went straight to the drum. If the drum was not spinning correctly I am sure Martin would check all that is necessary to fix it and that was the case.
Demetris

Posted by Victor Liorentas (Member # 5272) on 07-25-2009, 11:46 PM:

Despite Demetris having seen this 2 times. I see why Tony would ask about digital error rate and i agree with his quick connect the dots approach!

Posted by Scott Christopher (Member # 834) on 07-26-2009, 07:14 AM:

quote:
What I was simply saying and nobody seems to have understood is that when a client says that something is working fine your should not start checking the things that are working fine!

I've found MANY times what the client THINKS is working fine, actually isn't. The digital may be working, but the error rate is higher than usual.

If there's a problem with optical sound I start from the sound head and work my way through the system... Even if the client has reported digital is ok (in a basement reader setup).

Posted by Tony Bandiera Jr (Member # 2365) on 07-26-2009, 01:31 PM:

Victor and Scott, thanks for your support on this. Some people cannot be convinced that there are other and sometimes better ways to troubleshoot problems. Perhaps the methods they use have worked well for them, but then again they may not be on the clock and expected to get to the bottom of a problem in the shortest time possible, and without making a lot of incorrect guesses.

When dealing with ANY troubleshooting, it pays to look at the WHOLE picture to help pinpoint the actual cause of a problem. The time spent looking at the whole picture is a LOT less than the time wasted chasing a wrong diagnosis and repeat service call. For example this, which was a 4-hour(!) call which, had I applied a bit more logic from the start, could have been found in 20 minutes:

quote: Me a few posts back
Example of unusual cause/effect: Customer had a CP-200 that would randomly switch to Format preset "D" (set for non/sync in that case) with no thumps or other drop-outs in the sound. After disconnecting the automation connection (rules out automation issue), pulling and re-seating ALL of the cards (rules out bad connection at the cards), pulling, inspecting and re-seating the power supply DC bundle (rules out bad Molex connections/loose pins) the problem persisted. What I eventually found, was that in the rat's nest of power cords (ALL the plug ends were cut off and tied in by a terminal strip) that the neutral on the CP-200 power supply cord's screw was loose. Tightened up the screw and no more problems. The loose connection would interrupt the power just long enough to fool the logic circuits into thinking the processor was powering up, but not long enough to make a thump in the sound. I found the bad connection when I kicked the rack in frustration.

In Martin's case, yes it turned out to be a mechanical issue, which WILL show as higher error rates in Digital. Had Martin mentioned or noticed that, it would have led to a quick pinpointing of mechanical trouble. BUT, let's say the Digital errors were running at 1-2 or 3, but the analog sound was a mess. NOW we can say let's focus on the analog part ONLY, as now the trouble could be:

Bad optical lens focus;
Oil in the optics (good call Mark);
LED for analog bad;
Power supply for analog bad;
Electronics for analog bad;
"A" Chain needs adjustment.

Demetris mentioned the following:

quote: Demetris Thoupis
If the drum was not spinning correctly I am sure Martin would check all that is necessary to fix it and that was the case.

I agree with that, BUT: how many people can look at that drum and see it's not spinning "correctly"? With the flywheel loose it may, to the inexperienced eye, APPEAR to be spinning correctly. Only if the bearings are grossly tight or some other issues cause it to spin VERY erratically the average projectionist will NOT be able to tell that it is the problem.

And if it was so obvious, I doubt Martin would have asked us for help, he would have perhaps made a "Did this ever happen to you" kind of posting.

quote: Demetris Thoupis
Hmm so when there is no sound in the auditorium I need to take the ladder and check first if a speaker cable is out, then go back to the amplifiers to see if the cable is out, then see if the signal cable from the amps to the processor is damaged and THEN check if they are off!! Hmm does not sound like a good advice to me. Sorry but his point clearly mentioned analogue sound. Someone saying that analogue has a problem means that the analogue has a problem! .....

Now that's the kind of smart-ass attitude I was talking about. You need to open your mind and close your mouth a bit and you'll find a lot of things that you don't know, just like I have found out after 26 years in this business there are LOTS of things that I don't know!! Why do you think I have continued this job for so long? Because I like encountering new things and situations and when the day comes that it gets to be routine that's when I'm retiring. [Big Grin]

You can ask other techs here on F-T and find out that I have asked questions to get to the bottom of something I couldn't figure out. It's all part of the learning curve.

Oh, and by the way, on the screening room I'm currently updating for D-Cinema, the HF horn for the left channel was out. AFTER checking the processor, crossover, amp and yes the cabling connecting to the amp, the problem was simple: someone had stepped on the cable backstage and pulled the wire out of the driver's terminals. And yet I STILL fell into the trap of ASSUMING at first that the driver was blown out. Good thing I dug deeper before ordering the parts.

quote: Gordon McLeod
I think two people need to take a valium
they are many methods of troubleshooting and often the equipment type or common method of installation in a given region needs to be taken into account

LOL as for the Valium, I don't need to, I don't get riled by people I don't know. [Smile]

But yes you are absolutely right, there ARE many methods of troubleshooting and yes region and equipment play into it. BUT a basement reader here in California and a basement reader in other parts of the world will still operate on the same basic principles and the same logic to find the trouble apply.

It still boils down to looking at the WHOLE picture to help narrow down the possibilities. As I said above, IF we could have proven that the Digital in this case WAS "fine", with NORMAL LOW ERROR RATES, then of course the cause of the problem would NOT have been the mechanical issue that Martin had.

Posted by Tony Bandiera Jr (Member # 2365) on 07-26-2009, 03:34 PM:

quote: me with dyslexia
Only if the bearings are grossly tight or some other issues cause it to spin VERY erratically the average projectionist will NOT be able to tell that it is the problem.

That line should read:

Only if the bearings are grossly tight or some other issues cause it to spin VERY erratically, the average projectionist might be able to tell that it is the problem.

It is totally wrong as originally posted. A few misplaced words makes a big difference.

Posted by Tim Reed (Member # 137) on 07-26-2009, 09:05 PM:

quote: Scott Christopher
I've found MANY times what the client THINKS is working fine, actually isn't.

This is true. Especially if you ask them on the phone and they say "yes" before you even finish the question. That has proven to be a big red flag for me. I have saved myself countless unnecessary trips, and client down time, just by not accepting broad statements of condition as 100% fact. It often helps to approach in a circular fashion and zero-in on the problem.

I'm not saying this is the case with Martin, but some people think that if a pilot lamp is lit, the device is working.

Posted by Monte L Fullmer (Member # 2797) on 07-26-2009, 11:50 PM:

quote: Tim Reed
but some people think that if a pilot lamp is lit, the device is working.

May I borrow an incident from a movie that had this similar situation:

How many of us remember Universal's "Patch Adams?" There was a section that one can take heed from that really holds true-which also includes what Tony's coming across and from what Tim above quotes:

Remember the scene where the one patient had "Patch" hold his hand to his face and ask him how many fingers he could see? Course, the answer was obvious 4 fingers..and the patient told him that he was wrong. Moving towards the movie, the patient had him do the same test again, this time "Patch" could see more,and the patient told him that he was right...

People, in general, only see what's in front of them (like if the bulb is lit, everything is okey..as what Tim mentions), but if we can see "past our noses" - "past the okey" - then we really can see what we really need to see.

Here's an example that happened to a fellow worker of mine: He comes back from the shop from having his car worked on since he had mentioned of a strange engine noise and an oil change. It still has the noise and the shop told my friend that he's looking at major engine repair bill.

Out of my curiosity, we went out to the car, he started it up and there definitely was the noise. I told him to stop the motor and I pulled the dipstick - bone dry. I then asked my friend, "didn't they change the oil as requested?" I went to the local quickcare auto parts place, bought a 5quart container of oil, shoved it down in the oil fill which got the oil level up on the dipstick, he started up the car and the noise was definitely gone.

I then told my friend to go back to that shop and raise some hell on this one...which he did.

Case in point: shop heard the noise and said 'motor repair' (even though I'm sure it was planned that way so they could earn his business back....), I went farther and with a simple check found the problem being no oil in the crankcase.

I also agree with Tony: being a tech is a continual learning experience, sometimes on a trial and error basis (which is actually good for us for that helps up to really remember what we experienced) - we never will get all the learning that we always need since it's always changing..

quote: Tony Bandiera Jr was the last to post
Only if the bearings are grossly tight or some other issues cause it to spin VERY erratically

May I borrow this statement as well: Thx to STRONG not having pressed in bearings on their 5-star units, how many of us seen grooved out scanner drum shafts due to bearing failure, yet the scanner drum still rolls smoothly in the normal eye? Why, when I do belts on the 5-star units, I spin both the scanner drum shaft and the main drive shaft with the flywheel/pulleys off so I can check these bearings out.

-Monte

Posted by System Notices (Member # 2357) on 02-13-2013, 07:52 AM:

It has been 1297 days since the last post.

Posted by Allan Riddelll (Member # 5090) on 02-13-2013, 07:52 AM:

On much the same subject regarding analog sound distortion, am having problems regarding sibilance mainly during music passages *particularly high freq and piano . equipment involved Kinoton FP50 reverse scan. Any help from you guys and gals appreciated. Not speaker trouble as digital not affected. Optics thoroughly cleaned and rubber o rings replaced either side of sound pressure roller as a precaution but to no avail.

Posted by Sam D. Chavez (Member # 1841) on 02-13-2013, 09:57 AM:

This is not a mechanical problem. It could be a number of things having most likely to do with slit loss adjustment.

You don't mention the processor so can't comment further as to what to do.

Posted by Jim Cassedy (Member # 4115) on 02-13-2013, 10:12 AM:

quote: Martin McCaffery
Anyone ever have that screw come loose on its own before?

Yes, but it was because someone had not re-assembeled the
soundhead drum back on the shaft properly to begin with.

Posted by Allan Riddelll (Member # 5090) on 02-14-2013, 03:43 AM:

Thanks Sam. Processor is a Sony DFP D3000. Would playing the track in mono for the time being solve the distortion prob.

Posted by Louis Bornwasser (Member # 3063) on 02-14-2013, 09:53 AM:

Hard to say with a Sony in optical. (Their optical is decidedly bad)

If this were a Dolby, I would assume radical overload of something, perhaps hf controls up full on preamp card or level problem internally.

"It's a Sony!" Louis

Posted by Sam D. Chavez (Member # 1841) on 02-14-2013, 10:27 AM:

Allan,

I don't know the Sony at all but assume it has some sort of slit loss correction on the optical preamp. I would start by turning this down.

Reverse scan readers have freq. response to 12 Khz and beyond so there's not much useable audio up beyond there.

It's strange you hear it on piano, it almost suggests wow and flutter problems which are mechanical

Posted by Louis Bornwasser (Member # 3063) on 02-14-2013, 03:01 PM:

I read that differently, Sam. Voice and piano have a lot of irregular, almost square, waves. Sometimes they will be the first overload you hear. (Piano has an attack that can be very much more than the remainder of the wave.) Louis

Posted by Brad Miller (Member # 2) on 02-14-2013, 11:50 PM:

quote: Louis Bornwasser
Hard to say with a Sony in optical. (Their optical is decidedly bad)

That's the answer. The Sony DFP-3000 has a HORRIBLE optical A-chain. Just awful.

Posted by Allan Riddelll (Member # 5090) on 02-16-2013, 06:12 AM:

Sam

Further to my post regarding analog distortion, I replaced the analog board in the Sony processor with no success. You were probably right in your assumption that it is indeed a wow and flutter problem, so therefore mechanical. I have a selection of Dolby test loops which I can use so where do I proceed from here.

Posted by Sam D. Chavez (Member # 1841) on 02-16-2013, 10:08 AM:

If it's mechanical, it could be anything from o rings to bearings to downward pressure of the lateral guide roller. The only loop that will measure flutter wow is a flutter bridge and it just gives you a percentage #. Usually high flutter and wow is a symptom not the cause as it were so it will not go away until you find the problem.

Posted by Rob J. Buskop (Member # 3338) on 02-24-2013, 01:14 PM:

A couple of years ago I had a late nineties reissue copy of Sound of Music here, with Dolby A soundtrack. It looked like new.
The film actually could not be shown because off the erratic
scratchy and heavily distorted sound......
After much ado, I finally examined the track, that seemed at first to be in pristine condition.
Now I scrutinised the track under the microscope.
Then and only then the culprit showed it's ugly head: The masking
of the dark magenta analog track was riddled with myriads of very small orangy "globules" that were randomly present.
Clearly a lab fault, and one that, as it turned out had started much earlier showing itself and which had worsened over time to the point of the film being useless and un-runnable.
Another copy that crossed my path with somewhat similar defects
was a print of Zefferelli's "Tea with Mussolini". But here the
effects were in the image area and larger in size.
Anyway, before starting to blame the hardware it's always a good idea to have a really good (and magnified..) look at the film
first. Just my cent's worth of some 40 years experience...

Posted by Gordon McLeod (Member # 33) on 02-25-2013, 11:20 AM:

That orange splatter was caused by the applicator that applied a almost gelatinous redevelopment solution to the sound track area
It was either applied by a small spinning wheel or a small nozel

that was one of the issues that the caused a lot of rejected prints as processing speeds increased to meet print demands and deadlines