Film-Tech Forum ARCHIVE: CE LS-40 LED issue

This is topic CE LS-40 LED issue in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Tom Wienholt (Member # 1510) on 06-26-2015, 05:50 PM:

I am having trouble achieving dolby tone. I have boosted the pre-amp gain controls of my CP65 and the gain control on the LS-40 power supply all the way up. Aside from replacing the LED itself, is there any other way of boosting the gain? Thanks!

Posted by Sam D. Chavez (Member # 1841) on 06-26-2015, 06:46 PM:

The LEDs do age and around 5 years more or less you can no longer reach Dolby level.

There may be a high gain jumper on the the preamp. This boosts the gain (and noise) by about 6dB and may get you by.

There is the possibility the LED bracket has moved and the red LED may not be in the sweet spot.

Most likely though the LED's are worn out.

They are available from BACP, CE, or Kelmar. Prices do vary for the identical Dolby part.