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VACCUM TUBE LAYOUT
Top Panel
This section is dedicated to those who do not have an abundant amount of experience with tube amplifiers. The
above drawing is an illustration of the top panel of your Fusion F35. Your amplifier uses a complement of 8
tubes spread over three vacuum tube types. This tube complement is made up of 4 pieces of 6CA7/EL34s or
6550s and 4 pieces of 12AX7s. Please note that the vacuum tube type KT88 to KT150 can be used in place of
the 6550s. The placement of the tubes in their correct socket is critical. If you need to replace a tube, consult
the tube layout for positioning. The placement of your tubes in your amplifier is:
V1 = 6550/EL34 tube type
V2 = 6550/EL34 tube type
V3 = 6550/EL34 tube type
V4 = 6550/EL34 tube type
V5 = 12AX7 tube type
V6 = 12AX7 tube type
V7 = 12AX7 tube type
V8 = 12AX7 tube type
These tubes are readily available at Specialty Audio stores, guitar amplifier stores in your local area, mail order
houses for guitar and audio equipment as well as internet sites that specialize in vacuum tubes (search Vacuum
Tubes) The majority of professional guitar amplifiers sold are tube driven since the music industry uses the best
sounding amplifiers for professional reasons. The vacuum tubes in your Fusion F35 amplifier are rated for 3,000
hours of life. The average usage of an audio amplifier is 500 hours per year or 10 hours a week so changing
the power output tubes should be every 6 or more years. Our experience is the 12AX7s (smaller front tubes)
should last 6,000 hours. There is no exact method for determining the life of the tube since the life expectation is
a combination of how the tube was built, how it is used, and how long it is operated.
Handling a tube amplifier is not complicated even though most people are used to solid state. Replacing tubes
every six years or more, and taking time to bias the amps are not difficult especially with the Exact Biasing
System. What you get with a tube amplifier is a reliable piece of electronic equipment that can give you years
of service. Many people remember tube equipment in terms of old radios in the 1940s and 1950s. However, in
the past, tube equipment was known for its reliability and, in fact, vacuum tubes currently are still in widespread
use. Radar, microwave ovens, ham radios, guitar amplifiers, cat scanners, X-ray machines, plastic sealing
machines and power radio transmitters, to name a few types of equipment, still use vacuum tube technology.