YAMAHA REVSTAR

87
JUNE 2022 GUITARIST
YAMAHA REVSTAR
UNDER THE HOOD
Let’s see what powers these Revstars… is that a transformer?
T
here’s a surprise on opening the
control cavities: all the models with a
Focus Switch have a small transformer
lurking in the corner – something we’ve
never seen in our many years of writing about
guitars! The rest of the circuit is simple:
small Alpha 500k audio pots for volume and
tone, the latter with a pull-push switch that
introduces either the Focus Switch or, on
Element models, the Dry Switch from the
previous series. Both the Dry Switch (which
introduces a bass cut) and treble bleed on the
volume controls use a simple capacitor and
resistor wired in parallel. The Dry Switch uses a
.0033 microfarads cap (like the famous Fender
Jaguar ‘strangle’ switch) and a 330k resistor;
the treble bleed uses the same resistor with
a 561 code cap, which indicates a value of
.00056 microfarads (or 560 picofarads).
While the actual theory involved in the
position 2 and 4 sounds on the five-way
selector is complex, it’s achieved in a simple
fashion. The neck pickup, for example,
is voiced in positions 5, 4 and 3, but in
position 2 it passes through a capacitor (the
same-value .0033 microfarads cap used in
the Dry Switch), attenuating the low-end.
In position 1, the neck pickup is not voiced.
Now, the bridge pickup is the reverse of this:
it functions in positions 1, 2 and 3, and in
position 4 it passes through another .0033
cap to thin the sound. So while positions 1, 3
and 5 are standard (bridge, both and neck), in
position 2 we have the full bridge humbucker
with the thinned neck humbucker; in
position 4 we have the full neck humbucker
with the thinned bridge humbucker.
“The intention of the capacitor is to shift
the phase of the pickup slightly (not like the
typical out-of-phase sound) and create a taste
of a ‘half-tone’ sound when they’re mixed,”
says Takashi Yamashiro, manager of Guitar
Development. “You can get more variety of
sound from a two-humbucker guitar.”
Fender uses a similar concept on the Baja
and Vintera ’50s Telecaster Modified where
a .01 microfarads capacitor, wired to ground,
applies a high-frequency roll-off to the
neck pickup. This means it produces a less
Not what you’d
expect to see in your
guitar: a transformer!
Along with that Focus Switch
transformer in the RSS20, you can
see the two capacitors on the four-
pole five-way switch that are the
key to the mixed pickup sounds
The circuit in the RSP02T is
identical to the other Standards,
although it uses slightly different
capacitors, albeit of the same value
“We modifi ed the
humbuckers to
get more high-
frequency brilliance
and cut-through”
‘strangled’ sound when it’s mixed in parallel
and out-of-phase with the bridge pickup.
What about the Focus switch? “We
designed a custom small transformer for
it,” says Takashi. “By passing [through]
a transformer, the signal level could be
increased a little without a battery and also
shift the frequency range. It could give an
effect as if the pickup is overwound. The
construction is like a standard transformer,
but we tried several types…”
Although the pickup names are the same
here as they were on the original Revstars,
Takashi explains that “every time we develop
a new model, we like to match the pickups
to the new construction as well. This time,
we modified the humbuckers to get more
high-frequency brilliance and cut-through by
changing materials. As of the P-90, however,
it’s the same one as the original models.
We had great feedback from artists and
customers on the originals and it matched
the new construction very well.”
The baseplates of the Element’s ’buckers
are brass and bear the standard G&B logo.
Moving up to the Standard’s humbuckers,
the baseplates are nickel-silver and state
“Yamaha Guitar Development MFG by G&B”.
They also have an etched YGD logo on the
cover’s corner, unlike the Element’s units.
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