Octave HP 700, Manual

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TROUBLESHOOTING
Troubleshooting
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TROUBLESHOOTING
Troubleshooting
Hum and crackling
Hum in an audio system is often caused by several system components being grounded individually. It is
particularly common with tuners, VCRs, or satellite receivers, where the grounded aerial cables cause a
ground loop via the aerial input.
Power amplifiers are normally also grounded. Removing the ground wire on
your safety plugs is not a solution. You can isolate the aerial earth connection with a special signal isolator.
This device has no adverse effect on the sound or picture quality of tuners or TVs.
The HP 700 is not grounded and therefore cannot cause ground loops.
Solution The XLR output on the HP 700 can be connected without ground connection to interrupt a
ground loop in the power amplifier with a grounded source device. Alternatively, the IN 8 line
input module can be used. This transformer-coupled XLR input module also allows for ground
separation.
Clicks and pops
Older refrigerators and 12 V halogen lamps can generate strong radio interference, and when they are
switched on and off, audible clicks and pops in the system’s loudspeakers may occur.
Solution The only solution is to use a single-power socket board for your entire system and to use a
different power outlet in your listening room.
Channels are not balanced
Check that the RCA plugs are plugged in properly. Bend the outer ground contacts inward if necessary.
Sometimes the internal pin in an RCA plug may not be a tight enough fit, in which case you should either
replace the cable or the socket.
1) Damaged cables and poorly fitting RCI plugs can create resistance in the signal path, enough to reduce
the output level of one channel.
Solution Try new cables or clean plugs and sockets with isopropyl alcohol. You could also try cleaning
or contact fluid.
2) A faulty tube can cause a drop in output in one channel and generate distortion. This is a rare occurrence,
the heater inside the particular tube may also be the cause of the problem.
Solution Replace the tube.
Increased hiss on one channel
Hiss that varies in level is a sign of a faulty or worn driver tube.
Solution Replace the worn tube.
Tubes with this type of error can generally still be used in power amplifiers; the increased hiss
is rarely an interference.