Orban OPTIMOD 5750 Operating Manual page 112

5-5
Orban 5750 Technical Manual Troubleshooting
You will always achieve better peak control by defeating the pre-emphasis and input filters of an external stereo
encoder, permitting the 5750 to perform these functions without overshoot.
Dull Sound
If you are using the Two-Band structure, dull-sounding source material will sound dull on the air. The Five-Band
structure will automatically re-equalize such dull-sounding program material to make its spectral balance more
consistent with other program material.
If the 5750's output is set to Flat in System Setup > Output, there will be no pre-emphasis unless it is supplied
somewhere else in the system. This will cause very dull sound.
System Will Not Pass Line-Up Tones at 100% Modulation
This is normal. Sine waves have a very low peak-to-average ratio by comparison to program material. The processing
thus automatically reduces their peak level to bring their average level closer to program material, promoting a more
consistent and well-balanced sound quality.
The 5750 can generate test tones itself. The 5750 can also be put into Bypass mode (locally or by remote control) to
enable it to pass externally generated tones at any desired level.
System Will Not Pass Emergency Alert System ("EAS" USA Standard) Tones at the Legally
Required Modulation Level
See System Will Not Pass Line-Up Tones at 100% Modulation (directly above) for an explanation. These tones should
be injected into the transmitter after the 5750, or the 5750 should be temporarily switched to BYPASS to pass the
tones.
System Receiving 5750's Digital Output Will Not Lock
Be sure that the 5750's output sample rate is set match the sample rate that the driven system expects. Be sure that
the 5750's output FORMAT (AES3 or SPDIF) is set to match the standard expected by the driven system.
You See A "Communications Board Error" Message
This can be caused by applying an AES3, AES3id, AES11, or AES11id to the 10 MHz/wordclock input. Use the XLR
AES3 input as an AES3 sync source.
19 kHz Frequency Out-of-Tolerance
First, verify that a problem really exists by using a second frequency-measuring device and/or verifying the problem
with a monitoring service. If the problem is real, contact Orban Customer Service for a crystal replacement; there is
no frequency trim available.