Recommendations; Troubleshooting - Margules I-240 Manual Del Usuario

RECOMMENDATIONS

The amplifier may be operated with or without the tube
protecting cages; however, by not leaving them installed
while the amplifier is operating, you will improve heat
dissipation.
Thanks to the Active Servo Bias developed by Margules,
you can change the tubes without making any kind of
adjustment, with the peace of mind of knowing that they
will always operate in their ideal range and in Class-A.
To change the tubes, they must be removed by slowly
pulling them upwards with gentle lateral movements.
They should not be removed abruptly, as ceramic
sockets with gold-plated connectors could be damaged.
If you change the tubes for another brand or allowed
type, you may obtain different sound qualities.
Nevertheless, changing the tubes constantly is not
recommended since this may damage the sockets.
When you need to change the tubes, we recommend you
substitute them with matched tubes (at least per
channel) and all the same brand and type.
When changing the tubes, make sure the positioning
guides are oriented correctly.
Do not substitute 12AU7 tubes with a different type
because this could increase distortion.
The useful life of tubes may last several years under
normal use conditions (two hours per day); however, for
an optimal performance of the amplifier, we suggest
changing the tubes every two years.
Avoid using long interconnect cables (longer than 10m),
since this may induce noise into the signal.
The quality as well as the DC offset in the AC powerline
are important to avoid any mechanical noise induced by
the transformers.
Placing the amplifier on vibration dampening or isolation
devices (spikes) usually
instrumental detail. The I-240 is an equipment sensitive
to small adjustments, therefore we recommend the use
of high-quality cables as well as firm amplifier stands.

TROUBLESHOOTING

1. The amplifier does not turn on:
Verify the equipment is correctly connected to the
•
mains power or AC power source.
Verify that the switch on the back of the amplifier is
•
on.
helps to improve the
Try again to turn the equipment on, by pressing the
•
switch of the source selector or by turning it to select an
input source.
• Check the electrical supply input fuse located at the
back of the amplifier. If it is damaged, replace it by one
that meets the correct specifications.
If the fuse blows again, directly contact our
•
technical support department.
2. The amplifier turns on and the LED indicators light
up but it no sound is heard:
Verify the source cables as well as the speakers'
•
cables are properly connected to the terminals on the
amplifier.
• Verify the source selector is placed at the position
corresponding to the right source.
3. One of the channels does not emit sound:
• Verify that the cables of the sources, as well as
those of the speakers, are properly connected to the
terminals on the amplifier.
Check that the LED indicators at the base of the
•
output tubes are on.
If the two LED indicators of a same channel do not light
up, it is possible that the Active Servo Bias fuse of said
channel is blown.
In that case, unplug the amplifier from the AC power
supply and wait a few minutes. Check the fuse
corresponding to the channel that does not emit sound,
which is located at the back of the amplifier (near the
speakers' terminal).
In case the fuse is blown, one of the tubes of that
channel has failed, so you should replace both tubes.
Never replace these fuses by other of different
characteristics.
4. The sound is distorted or a humming sound is heard
(coming from one of the channels only):
Check that both the source cables and the
•
speakers' cables are properly connected to the
terminals on the amplifier.
Make sure the source of the signal is operating
•
correctly.
Verify the tubes are properly installed on their
•
sockets.
ENGLISH - 20