If we look under the hood we find three
tubes: the preamp tube is a Groove Tubes
12AX7; the power tube is a GT 6V6GT; and
the tube rectifier is a Ruby (Chinese) 5Y3.
The speaker input jack has mercifully been
changed from an RCA phono to a 1/4"
TS jack. The tube sockets, all connections
to other components and the component
mounting eyelet board are all expertly
handwired and soldered. There are three
internal fuses (new) and one external fuse
(original). The power supply transformer is
beefy, as is the output transformer—both
made by Schumacher, which have been
used in Fender amps since the ‘50s. All
components are of very good quality and
tight tolerance. The speaker deserves special mention, being designed and manufactured for Fender especially for this amp by
Ted Weber of Weber VST. It uses an Alnico
magnet with no bell cover to allow it to fit
into the tight space afforded.
AB, some use a mix of the two modes and
some use pure class A. Class A lends itself
nicely to small, low-power amps. Larger,
higher-powered class-A amps can be identified by their heavy weight, high price tag,
and high heat (often requiring cooling fans).
What makes the Class-A amp desirable for
many guitarists is the way the output tube
distorts. Class-A output distortion strongly
favors the even order distortion overtones,
while class AB favors the odd order overtones. Even order distortion is far more
pleasing to the ear in most situations and is
Why all the Fussy Tech Stuff?
What is it about this Champ that spawned
a demand for its reissue when Fender
already has a few Champ models in its
present-day lineup? The 5F1 Champ is a
single-ended, Class-A-operating, cathode-biased circuit. Its main change from the
preceding 5E1 circuit was the change of
the power supply to a capacitative input
filter power supply, which added low end
and a punchier attack envelope. Later
circuits added a negative feedback loop
to the output to flatten out the frequency
response. This would be a characteristic of
the blackface circuits with their increased
high end and scooped mids, while the lack
of negative feed back would be a characteristic of the “brown sound” of the tweed
generation represented by this amp.
Class-A operation essentially means that
the power tube is running at full power all
the time, as compared to class-AB/push-pull operation, which requires at least a
pair of power tubes, and each side “rests”
in either the positive or negative excursion of the speaker. Class-A operation
requires a heavier power supply and output
transformer designs, and due to its high
operating temperatures will cause tube and
component failure in fewer hours of operation. Most modern tube amps use class
