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Optical sound troubleshooting: Difference between revisions
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(Created page with "These are some examples of common optical sound issues, and their potential causes and remedies. =Buzz/Hum= Buzz and Hum can be caused by: 'Ground Loop': If there is a hum...") |
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Buzz and Hum can be caused by: | Buzz and Hum can be caused by: | ||
'Ground Loop': If there is a hum in the system with no film running, there is likely a ground loop. | '''Ground Loop''': If there is a hum in the system with no film running, there is likely a ground loop. | ||
'Light leak': Check for light from an overhead light or a reflection from the port window spilling into the optical sound system. | '''Light leak''': Check for light from an overhead light or a reflection from the port window spilling into the optical sound system. | ||
'Lateral Guide Roller Alignment': Film is not properly aligned in the soundhead, and the solar cell is picking up parts of the image, DTS timecode, or perforations in addition to the soundtrack. Align with [[Buzz Track]] test film as described in your projector's manual. | '''Lateral Guide Roller Alignment''': Film is not properly aligned in the soundhead, and the solar cell is picking up parts of the image, DTS timecode, or perforations in addition to the soundtrack. Align with [[Buzz Track]] test film as described in your projector's manual. | ||
'Damage to Optical Soundtrack': scratches, gouges, or sprocket run can cause audible buzzing. If damage is limited to only one side of a mono track, the undamaged side can be isolated by blocking off half of the slit lens or solar cell with a business card, or bringing the gain all the way down on the left or right channel. | '''Damage to Optical Soundtrack''': scratches, gouges, or sprocket run can cause audible buzzing. If damage is limited to only one side of a mono track, the undamaged side can be isolated by blocking off half of the slit lens or solar cell with a business card, or bringing the gain all the way down on the left or right channel. | ||
'Shrunken Optical Soundtrack': Print is shrunken and not aligned laterally in the soundhead. As with soundtrack damage, part of the track can be blocked off with a business card. The lateral guide roller can also be adjusted to the shrunken film, but must be set back afterwards. Consult your projector's manual for this adjustment. | '''Shrunken Optical Soundtrack''': Print is shrunken and not aligned laterally in the soundhead. As with soundtrack damage, part of the track can be blocked off with a business card. The lateral guide roller can also be adjusted to the shrunken film, but must be set back afterwards. Consult your projector's manual for this adjustment. | ||