Active/Passive Retro-Fit for P-Style Basses
• OPERATIONAL DESCRIPTION
The P-Retro is based on a novel dual mode circuit which has a flat response setting, a conventional variable frequency
mid range boost, as well as a combined bass/treble boost. A ‘deep’ setting is available too, as well as a bright option.
NOTE: With regard to knob rotation:
CW = Turning a knob up towards maximum or clockwise
ACW = Backing a knob off, turning it anti-clockwise or counter-clockwise
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Tone
Volume
ACTIVE
Deep
Frequency
Dual Boost
• P-RETRO - PASSIVE MODE
• Volume knob push/pull switch in its down posi-
tion, sets the P-Retro into its Passive Mode.
• This is exactly like the stock instrument Volume
and Tone controls, except that the knobs are
stacked instead of separate.
• In Passive, the active circuit is bypassed, and the
signal from the Volume is passed directly to the
jack, via a high quality relay.
• P-RETRO - ACTIVE MODE
• Volume knob switch pulled up, sets the P-Retro
into its Active Mode, bringing the active stack into
operation.
• The Volume and Tone work as normal but their
output feeds the active circuitry, which in turn
feeds the jack.
• When the Boost knob is in its centre click, there is
some additional gain with a flat response.
• Turning the Boost knob CW from its centre click,
boosts the mid spectrum according to the Fre-
quency knob setting.
• Turning the Boost knob ACW from its centre click,
boosts the bass and treble spectrums combined,
with overall balance set by the frequency knob.
• Pulling the Boost knob actuates an internally pre-
set Deep boost.
PASSIVE
Volume
Tone
X