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Author Topic: Analogue Sound Problem
Ian Bailey
Master Film Handler

Posts: 317
From: Nambucca Heads, Australia
Registered: Jun 2003


 - posted 01-28-2008 01:03 AM      Profile for Ian Bailey   Email Ian Bailey   Send New Private Message       Edit/Delete Post 
This is the same machine that has the Ghosting(or Flaring) problem I'm trying to resolve.
There is a hum in the analogue system that can be easily heard in the monitor speaker....not so easily heard in the auditorium.....my hearing is also pretty bad.
But what I can hear in the auditorium when running an analogue show...which has normal dialogue and no extra sounds in the background ......is the Hum increases when there is dialogue and is a lot less in a quiet patch of the show.
JUNO was the one I noticed this on.
It's not the print as we've ran this print in another house.
The equipment is:
Component Engineering Red Led/Reader
Component Engineering Power Supply(only recently installed)
CSP1200
Crap Twin amps
Crap Monitor
The general hum in the monitor can be stopped by pulling either or both of the inputs(will check this again)to the top twin amp which drives the Left & Centre speaker.
I ran out of time to check any further.....and I wanted to get you guys opinions on this one before I have another look.
At the moment all our shows are DTS in this house so there is no rush.
Cheers Ian

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Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002


 - posted 01-28-2008 02:19 AM      Profile for Michael Schaffer   Author's Homepage   Email Michael Schaffer   Send New Private Message       Edit/Delete Post 
What happened to your funny hat?

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Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 01-28-2008 02:39 AM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
pull the CE reader out and chek the attached leads going into that phoenix (green) plug and see if any of the cel leads have came loose and retighten the screw taps down...for machine vibration loves to work them screws loose and you might have either a hot or gound wire loose in that plug.

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Ian Bailey
Master Film Handler

Posts: 317
From: Nambucca Heads, Australia
Registered: Jun 2003


 - posted 01-28-2008 04:22 AM      Profile for Ian Bailey   Email Ian Bailey   Send New Private Message       Edit/Delete Post 
Hi Michael
I submitted another photo of me holding a bloody big fish I caught right out the front of my house......but Brad doesn't seem to like having more than one person in the photo [sex] ......so now you've ended up with my bloody ugly head!!
I'm semi retired at the moment(and very poor!!) so most of my time is spent at home doing house duties while my lovely wife slogs it out at The Pickle Factory to make a few peso's.
I could send a "Tuesday's" shot of me which is Nude Ironing Day!
[Eek!]

Monte
That was going to be my approach to this.....check connections from Red Led to CSP1200 inputs.I know the shielded cable to the CSP1200 input runs in some couduit with a few other nasties....amd there is a join in the cable.
The Reader power supply was replaced not that long ago and the led was replaced recently(by a service tech).
I have had problems before with the wiring connection for the Led housing.
What was unusual to me was the way the hum would increase with dialogue....not sure if I'm missing the obvious here but this seemed wierd to me.
I did run a Buzz track and set Dolby level without any improvement.
Will let you know how I go.....after Tuesday [Big Grin]
Cheers Ian

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 01-28-2008 05:53 AM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
I would disconnect the led and see if the hum is still there as you mention that the hum increases with changes in the track volume
I would suspect if that is verified that there is some AC on led current
Also is the hum present in non sync or digital

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Ian Bailey
Master Film Handler

Posts: 317
From: Nambucca Heads, Australia
Registered: Jun 2003


 - posted 01-28-2008 06:38 AM      Profile for Ian Bailey   Email Ian Bailey   Send New Private Message       Edit/Delete Post 
Hi Gordon
I'll try disconnecting the led......I think you could be on the right track here as I did notice that when I turned the led off there was a small residual glow.We have a toggle switch which we use to turn the led off for a No Show.....I know this could be done through the automation but haven't got around to that one.
I'll measure the voltage at the connector for the Led housing....so what your saying is there should be no AC voltage here? I'll also check the wiring terminated on the power supply to see if that's OK(no wires touching etc)
Non Sync and Digital work fine,,,no hum.
Cheers Ian

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