Boss V-Wah PW-10 Owner's Manual page 25

The Relationship Between the Wah Input Impedance and the Tone
Pedals known as "vintage" wah pedals have
a low impedance; this attenuates a guitar's
high-frequency component when a guitar is
connected to the pedal. However, this high-
end attenuation occurs in conjunction with
the wah's filter tone, the result being a pleas-
ant-sounding effect. Rather than using a low-
er impedance, the PW-10 models the effect
that this low impedance has on the tone.
Presence controls this effect. Turning the
knob completely to the right results in no at-
tenuation of the high frequencies, while the
high-frequency components become more
attenuated as the knob is turned further to
the left.
Creating "Custom" Wah Effects (Customize Mode)
Setting the knob at the center position results
in the tone produced when connecting gui-
tars equipped with single-coil pickups, while
setting the knob to the ten-o'clock position
produces the degree of attenuation you get
when connecting guitars with humbucking
pickups.
fig.11a
Single-coil Humbucking
25