Troubleshooting
1.
When I power on the amplifier from the rear rocker switch, nothing happens. What should I do?
Check to make sure that the power cord is properly connected to the amplifier’s Power AC inlet as well
as the AC outlet from the wall. If there is no problem with the power source, check the fuse unit in the
back panel of the amplifier with a Multimeter. If the fuse is blown, replace it with a new fuse, and try
turning the power on the amplifier again. If the problem still persists, contact your authorized VTL
dealer or the VTL factory immediately.
2.
When I try to power on the unit, the
Mute LED
blinks at a fast rate, and I cannot turn on the amplifier from the
Power On button
.
What is the problem?
The amplifier is indicating that there is a tube fault in your amplifier. Refer to Chapter 3 on how to
identify which tube causes the fault, and how to replace the faulty tube and clear the fault.
3.
I am getting a noise and hum coming from my speakers when I turn the amplifiers on. What can I do to
eliminate the noise?
It is recommended that you connect your audio components to a good clean AC ground in your system,
and for quietest operation it is recommended that all components be plugged into the same ground
potential (or same AC outlet.) In single ended mode a ground loop hum can result from a difference in
ground potential between different components in the system and it is recommended that the system be
operated in the balanced mode to defeat ground loop problems. Under no circumstances should you
attempt to defeat the ground with a ground lifter cheater plug, as serious damage to the components and
yourself could result. If the noise persists you should either contact your dealer or the VTL factory to try
to resolve this problem.
4.
I am getting a noise and hum coming from my system when I plug in a video source. What can I do to
eliminate the noise?
The noise may be coming in from your video cable system. First disconnect the video component from
the system to see if this will solve the problem. If it does then you will need to try to lift the ground from
the cable TV wire by means of a cable ground-lifting transformer available from most electronics stores.
If the problem still persists contact your VTL authorized dealer or the VTL factory service department.
5.
I am getting a ringing noise from the amplifier when I touch or bump it. What should I do?
One or more of the tubes in the amplifier may be microphonic and the source of the problem. Follow
the procedures listed in this manual to remove the tubes and change them for new ones.
MB-450 Series III Signature Monoblock Owner’s Manual
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