C H A P T E R 4
Care and Maintenance of your VTL
Amplifier
Break In Period
Your VTL amplifier is a pure tube product designed to give you the continued optimum performance over a
long time period. Even though the amplifier has undergone a burn-in cycle in the VTL factory, the tubes and
circuits will require further usage and burn-in to reach maximum performance. During the first 100 hours of
usage the amplifier will undergo noticeable improvements in sound.
Power-on Period
We recommend that your amplifier should be powered-off when you are done with your listening session.
Leaving your amplifiers running idle when you are not listening to music will be a waste of electricity as well as
unnecessary usage of the tube life.
Tube Types
The VTL MB-125 Monoblock amplifier uses a total four EL34 tubes for the output stage and two 12AT7
tubes for the input and driver stages.
Tube Life
Your VTL amplifier has been designed to ensure long tube life. Tube replacement need not be considered
until after approximately 3000 hours of use (roughly 3 to 4 years depending on your listening requirements.)
As the tubes age beyond their peak performance they begin to lose their ability to provide full power. This
usually results in some loss of control in the bass and a general softening of the sound in the upper frequencies.
We recommend a complete replacement of all tubes in your amplifier at that time, which will restore it to a
“like new” sound quality. Your VTL dealer or VTL factory service department will be happy to assist you with
the re-tubing process.
Note: use only tube types and tube brands that are recommended by VTL. VTL specified
replacement tubes are available from your authorized VTL dealer or the VTL factory
service department. Any damage incurred to units which use non-VTL approved tubes will
not be covered under the warranty.
MB-125 Owner’s Manual
VTL
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