14
Symetrix 506E Headphone Amplifier User’s Guide
Troubleshooting
SYMPTOM
PROBABLE CAUSE / WHAT TO DO
No output
Check cables and connections to see if:
• Inputs are driving outputs, and outputs are driving inputs.
• Unit is plugged in.
• The DIRECT INPUT jack of the headphone channel you are monitoring
has a cable plugged in. If so, unplug this source.
Check controls to see if:
• PROGRAM INPUT and CUE INPUT gain controls are turned up.
• The gain control of the headphone channel that you are monitoring is
turned up.
• If the PROGRAM INPUT’s Mono/Stereo switch is set to MONO, try setting
the switch to STEREO (you may have a phase cancellation problem with
the signal that you are sending to the PROGRAM INPUT).
Verify cables, source, and load.
Replace or verify that headphones are in working order.
Hum or buzz in output
Check input and output connector wiring.
Check for a ground loop problem. Inspect related system equipment ground-
ing to verify that all system components are on the same AC ground.
Distortion
Check if line input signal is too hot or already distorted. If so, turn down the
PROGRAM INPUT and/or CUE INPUT gain controls.
Check the output loading.
Check if something else is clipping.
Check if you are overdriving your headphones. If so, turn down the output
gain control for the channel that you are using.
Noise (hiss)
Check input signal levels. The 506E is intended to operate at or near “line”
level (+4 dBu is nominal). Make sure that the signal you are feeding to the
506E is a line level signal, not mic level.
Check that all systems components are on the same AC ground.
Check gain settings on upstream equipment. The system gain structure
should be such that the 506E re4 dBu nominal signal. Check if the
input signal is already noisy.
No LED display
Check if unit is plugged in.
Verify that AC outlet works.
