Fishman PREFIX PLUS-T User Manual

PREFIX™ PLUS-T USER GUIDE

Thank you for choosing Fishman. Our goal is to provide you with the fi nest acoustic
amplifi cation products available; products that will compliment your style and let you
sound your very best onstage. Please read these instructions carefully.

Overview

The Prefi x Plus-T preamp offers the tonal variety and feedback-fi ghting
capabilities of Fishman’s deluxe Prefi x Plus onboard preamp system, with the
addition of a high-quality chromatic tuner and a streamlined new look.

The preamp module incorporates a unique fl ip-top compar tment for easy battery
access. Bass, treble, brilliance & semi-parametric “Contour” EQ let you quickly
dial in your personal tone. For real-world playing conditions, a problem solving
phase switch and notch fi lter help keep acoustic feedback under control. A
convenient low battery indicator rounds out the preamp features.

The Fishman Acoustic Matrix™ pickup used in the Prefi x Plus-T is regarded as
the industry-standard acoustic transducer. A unique proprietary co-polymer
sensing material is the secret to the Acoustic Matrix’ excellent sensitivity and
dynamic range. The transducer is fully EMI shielded and is comprised of a
multi-layer sandwich of co-polymer strips that run the length of the pickup. The
continuous length design allows the pickup to sense the motion of the entire
saddle length, for superb string to string balance and sensitivity to both the
strings and soundboard.

Plug and Play!

Plug a standard 1/4 inch instrument cable between the endpin jack and a stage
amp, a direct box or an unbalanced input on a mixer. When you plug in, the
Prefi x Plus-T switches on. To conserve the battery, unplug the instrument when
you fi nish playing.

Note: Turn down the volume on the amp or mixer before you plug in, to protect
your speakers (and your ears) from loud pops.

Setup

Battery Compartment

Pull the small tab at the top of the Prefi x Plus-T toward you. The body of the
preamp will swing out, revealing the battery compartment. Observe the polarity
marks on the battery compartment and install a fresh 9V alkaline battery
accordingly.

You can also turn on the tuner if the guitar is unplugged. It will automatically shut
down after about 30 seconds at idle to conserve battery power. The “in tune”
indicator will fl ash several times before the tuner shuts down. Note that the tuner
is calibrated to A = 440.

ABCDE FG #

Flashes when the note is below pitch

Lights up when note is in tune

Flashes when the note is above pitch

Lights up when the note is raised 1/2 step

VOLUME

Set this as high as possible (without causing your amp or mixer to distort) for
the cleanest signal.

NOTCH and PHASE

These controls work hand in hand to suppress two adjacent ranges of acoustic
feedback. When you set them properly, you can play your instrument as loud as
you like, feedback free.

Tune the NOTCH fi lter to scoop out the lowest range of feedback when you play
bass notes between the open low E string and (up to and including) the fourth
fret G sharp on the same string. Low frequency “cavity resonance” feedback
can usually be squelched by setting the NOTCH control between one o’clock and
two o’clock on the dial. Note that the NOTCH can be defeated by moving the dial
to the OFF (seven o’clock) position.

Push the PHASE switch in and out until you fi nd the position that sounds best
and subdues mid-bass feedback. Midbass feedback generally occurs when you
play bass notes above the fourth fret G sharp on the low E string.

Lower

Feedback Range

(E to G#)

Upper

Feedback Range

(A and above)

NOTCH

OFF 300 Hz

PHASE

BATTERY Indicator

Plug into the endpin jack and the BATTERY indicator will fl ash momentarily,
indicating the power is on. When the BATTERY indicator stays on, it is time to
change the battery.

Controls

TUNER

Depress the TUNER button to turn the circuit on and off. This digital chromatic
tuner accommodates all standard and alternate tunings. For your convenience,
the tuner button also acts as a mute switch. The tuner circuit devours battery
power, so turn it off when you fi nish tuning.

BASS

A boost here will add depth and weight to the sound the instrument.

CONTOUR EQ

Two sliders (CONTOUR and FREQUENCY) make up this EQ. The FREQUENCY
slider lets you tune in on the specifi c range of sounds that you can boost/cut
with the CONTOUR (level) slider. With the Contour EQ you can boost or cut a
wide range of frequencies, from gutsy low midrange (250 Hz) to brilliant, high
treble (10 kHz). Often your instrument will benefi t from a slight midrange cut.

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PREFIX™ PLUS-T USER GUIDE CONTINUED

PLUS-T

BRILLIANCE

+ 9 dB

­ 9 dB

FREQUENCY

250 Hz 10 kHz

TREBLE

+ 12 dB

­ 12 dB

CONTOUR

+ 12 dB

OFF 300 Hz

­ 12 dB

BASS

+ 12 dB

­ 12 dB

PLUS-T

BRILLIANCE

+ 9 dB

­ 9 dB

FREQUENCY

250 Hz 10 kHz

TREBLE

+ 12 dB

­ 12 dB

CONTOUR

+ 12 dB

OFF 300 Hz

­ 12 dB

BASS

+ 12 dB

­ 12 dB

PLUS-T

BRILLIANCE

+ 9 dB

­ 9 dB

FREQUENCY

250 Hz 10 kHz

TREBLE

+ 12 dB

­ 12 dB

CONTOUR

+ 12 dB

OFF 300 Hz

­ 12 dB

BASS

+ 12 dB

­ 12 dB

To cut mids, boost the CONTOUR control and then sweep the FREQUENCY
control until you find the band of frequencies that are brash and nasal sounding
(usually around the center of the FREQUENCY slider’s travel). Then move the
CONTOUR slider below its detent to taste.

TREBLE

A boost here will help to “cut through the mix”. Conversely, cutting the TREBLE
will mellow and subdue your amplified
tone.

BRILLIANCE

When boosted, the BRILLIANCE control can add presence to your sound or
brighten up dead strings.

Specifications

Nominal Input Level: -20dBV

Input Overload: (20Hz - 20kHz) -2dBV

Input Impedance: 20MOhm

Output Impedance: Less than 3.5kOhm

Nominal Output Level: -12dBV

THD: Less than .04 %, -20dBV input

Signal to Noise Ratio: 82dB

(A-weighted referred to nominal -20dBV input)

Suggested EQ Settings

Mid Cut

You can scoop out harsh midrange
by setting the FREQUENCY slider
slightly above center with the
CONTOUR Level cut to taste below
the center detent. You can also cut
midrange by
boosting the BASS and TREBLE
sliders to realize an “implied” mid cut
at 800 Hz.

Battery Life:

Preamp only, tuner off: 160hrs. @ 3.8mA

Tuner on, no signal: 71hrs. @ 7mA

Tuner on, with signal: 25hrs. @ 20mA

Power Supply: 9V Alkaline battery

(estimated 160 hours continuous use with low

battery indicator at 6.5V)

Notch Filter Range: 30Hz – 300Hz (-15dB)

Bass Control Range: ± 12dB at 60Hz

Treble Control Range: ± 12dB at 10kHz

Contour Control Range: ± 12dB

(adjustable from 250Hz to 10kHz) Q = 0.5

Brilliance Control Range: ± 9dB at 10kHz

± 3dB Bandwidth 5kHz

All specifications subject to change without notice.

Fingerstyle

This setting will add fullness to the bass
and definition to the treble.

Cut Through

For cutting through a live band mix at
high volumes.

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513-000-002 RevA 11-04