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TROUBLESHOOTING
I am using the amp for a subwoofer application and it sounds “rubbery”, what’s up?-
• Verify that the Clip Limiters are OFF. Why? The Clip Limiter is set to respond as quickly as possible after clipping is detected. On
low frequency material, this may be perceived as a “rubbery” effect. It may be preferable to turn Clip Limiting off, and let the amp
clip occasionally, especially if the speakers are robust.
• If your subwoofer is rated for frequencies below 50 or 20 hertz, set the Low Frequency (LF) filters accordingly.
The output sounds distorted-
• Indication: Clip indicator flashing- If the red clip indicator flashes before the signal indicator does, the load impedance is
abnormally low or shorted. Unplug each speaker one-by-one at the amplifier. If the clip LED goes out when you disconnect a cable,
then that cable or speaker is shorted. Try another cable and speaker to locate and/or remove the fault.
• Indication: Clip Indicator not flashing- This could be caused by a faulty speaker or loose connection. Check the wiring and try
another speaker. If not the speaker or connections, see next item to test for signal source distortion.
• The signal source may be clipping. Keep the amplifier gain controls at least halfway (19 dB or so) up so that the source does not
have to be overdriven. Reduce signal levels upstream of the amplifier to identify overdrive source.
No channel separation-
• Use a common AC ground connection for all audio equipment.
• Check the input cables for broken ground (shield) connection.
• Use balanced connections where possible for the entire signal chain.
• The design of the
amplifier eliminates internal hum fields, but external transformers or other magnetic devices may cause hum.
Move cabling and signal sources to identify "hot spots" in the system; then avoid those spots. Cables with faulty shielding are a
common entry point for hum. Use top quality cabling. Another common source of magnetic fields are “wall warts” or pluggable
transformers; keep input wiring away from them.
• Troubleshoot the system for ground-loop problems. Any identified ground loop must be broken using audio signal isolation. Do
not “lift” or break AC power grounds under any circumstance as safety of the system will be compromised.
• Check the mode switch settings on the back of the amplifier. If the mode switches are set for PARALLEL mode, there will be no
channel separation. The mode switches must be set for STEREO for each channel to operate independently.
• Make sure other equipment in the signal path to the amplifier, such as DSP, mixers, preamps, etc., is set for stereo, not mono.
There seems to be a lot of “hiss” noise on the outputs-
• Unplug the input cables to the amplifier. If the hiss goes away, then the problem is with the equipment or cables leading to the
amplifier.
• If the hiss is present with no audio input cables connected, check that the AC line cord is properly grounded at its connection to
the line. If the ground connection is OK and the hiss continues with no input cables connected, then the amplifier requires
servicing.
• To keep the normal noise floor low, operate the primary signal source at full level, without clipping, and avoid boosting the
signal further between the source and the amplifier.
The output has a “hum” noise-
