Fender Acoustic Junior, Junior Go, and SFX II Guitar Amplifiers

This document provides a comprehensive guide to the Fender Acoustic Junior, Acoustic Junior Go, and Acoustic SFX II amplifiers, detailing their features, controls, operation, and specifications.

Introduction

Fender's Acoustic Junior, Acoustic Junior Go, and Acoustic SFX II amplifiers deliver full, natural tone for acoustic-electric guitar and microphone, housed in specially tuned wooden cabinets. All three amplifiers feature wireless Bluetooth streaming, studio-quality stereo effects, an auxiliary input, and a headphone output. They also offer configurable XLR line outputs and USB ports for audio recording.

These amplifiers are ideal portable systems for solo performances. The Acoustic Junior and Acoustic Junior Go feature two channels, each with a variety of studio-quality stereo effects. The Acoustic Junior Go offers convenient, eco-friendly rechargeable battery operation, providing five hours of full volume from a single charge. With 100 watts of power, a single 8-inch speaker, a compression tweeter, a convenient kickback support, and lightweight design, both models are perfect for guitar and vocal practice and performances in various settings.

For solo performances or stage use with a band, the Acoustic SFX II amplifier boasts a dual-channel design with studio-quality stereo effects and impressive Stereo Field Expansion (SFX) technology. This technology goes beyond standard stereo to create room-filling tonal landscapes that envelop listeners in a rich acoustic experience. It increases the power output to 200 watts for enhanced guitar and vocal performance.

Image Description: Three Fender acoustic amplifiers are shown. From left to right: Acoustic Junior (smaller), Acoustic SFX II (medium), and Acoustic Junior Go (taller).

Control Panel

The control panel provides access to all amplifier functions. The following controls are available:

A. CHANNEL INPUT: Combination jack accepting XLR and high-impedance 1/4" inputs. Use for instruments or microphones. The XLR input provides phantom power for microphones that require it (avoid using ribbon microphones as they can be damaged by phantom power).
B. VOLUME: Adjusts the overall volume level, including headphone and USB/line outputs.
C. FX LEVEL: Determines the intensity of the selected effect.
D. FX SELECT: Selects from various effects including room and hall reverb, echo, delay, chorus, Vibratone, delay plus chorus, and delay plus reverb, indicated by the EFFECTS DISPLAY. No effect is selected when the control is fully clockwise or counter-clockwise. An optional footswitch allows tap-tempo control for delay time.
E. EFFECTS DISPLAY: LEDs illuminate to show the effect settings for each channel.
F. POWER INDICATOR: For Acoustic Junior and Acoustic SFX II, a green light indicates the amplifier is on. For the Acoustic Junior Go, a green light indicates sufficient battery charge, yellow indicates low battery, and red indicates insufficient charge or a battery fault. When plugged into AC power, the indicator flashes during charging and stays solid green when charging is complete.
G. PAIR: Bluetooth pairing button.
H. STEREO SFX (Acoustic SFX II Only): Controls the extent of the Stereo Field Expansion effect, creating a 360-degree stereo image using built-in effects and the side-mounted speaker. For SFX to be audible, an effect must be selected with FX SELECT and FX LEVEL set above minimum. Delay effects pan in stereo through the PHONES output and BALANCED LINE OUTPUTS if this control is set above minimum.
I. PHASE: Press to invert channel polarity to reduce feedback.
J. LOW, MID, HIGH: Adjusts bass, midrange, and treble frequencies.
K. LOOPER BUTTONS (REC/DUB, PLAY/STOP, UNDO): Functions for recording/overdubbing, playback/stop, and undoing the last recorded loop.

Note: The asterisk (*) indicates identical function for Channel 2 on the opposite side of the control panel. Refer to the "Footswitch" section for additional functions not on the control panel, including remote effects on/off, tap-tempo control for delay times, and the built-in tuner.

Diagram Description: A visual representation of the amplifier's control panel with labeled knobs and buttons: CHANNEL 1 (with PHASE, LOW, MID, HIGH, FX LEVEL, FX SELECT), VOLUME, LOOPER (REC/DUB, PLAY/STOP, UNDO), STEREO SFX, PAIR, POWER INDICATOR, and EFFECTS DISPLAY.

Back Panel

The back panel provides various input and output connections:

L. POWER: The main power switch for the amplifier.
M. IEC POWER INLET: Connects the IEC power cord. For Acoustic Junior, this connection is also used to charge the battery.
N. PHONES: 1/8" stereo headphone output that automatically mutes the speaker output.
O. AUX IN: 1/8" stereo input for connecting an external audio player. Use the external device's volume control for the accompaniment level.
P. BALANCED LINE OUTPUTS: Balanced XLR line-level outputs for connecting to external sound reinforcement or recording devices. Control panel setting changes affect the balanced line output signal, including aux input and Bluetooth signals.
Q. MONO/STEREO: "Out" position provides normal left/right stereo effect output, summing channels 1 and 2. "In" position configures both outputs to mono.
R. MARK LYFT (Ground Lift): "Out" position is for normal (grounded) operation. "In" position can help eliminate unwanted line noise.
S. MONO CONFIGURING: When the MONO/STEREO button (Q) is engaged, the "Out" mode sums channels 1 and 2 at both output jacks (CH2 + CH1), useful for small PA applications with minimal inputs. The "In" mode provides separate outputs for channel 1 and 2 (CH2 or CH1), useful for isolating instrument/vocal mixes for recording or performance.
T. USB-PORT: For audio recording. Connect a micro-USB cable (not included) to a computer with recording software. The computer's audio control panel will show "Fender Acoustic" as an audio recording device. Visit support.fender.com for setup help. Stereo USB output sums channels 1 and 2 (including aux input and Bluetooth signals).
U. RECOVER: For Fender service personnel use only.
V. FIRMWARE UPDATE: Instructions for firmware updates are available at support.fender.com.
W. FOOTSWITCH: 1/4" input jack for connecting the optional MGT-4 four-button footswitch.

Diagram Description: A visual representation of the amplifier's back panel with labeled jacks and controls: POWER switch, IEC POWER INLET, PHONES jack, AUX IN jack, BALANCED LINE OUTPUTS (P), MONO/STEREO switch (Q), MARK LYFT switch (R), MONO CONFIGURING switch (S), USB-PORT (T), RECOVER (U), FIRMWARE UPDATE (V), and FOOTSWITCH jack (W).

Pedal

The included magnetic overlay for the MGT-4 four-button footswitch should be applied to the footswitch for use with these amplifiers.

X. MODE LEDS: Indicate whether Channel 1, Channel 2, or Looper mode is selected via the MODE BUTTON (Y).
Y. MODE BUTTON/LED: Press repeatedly to select between Channel 1, Channel 2, or Looper mode, as indicated by the MODE LED (X). In tuner mode, this red LED indicates a greater degree of pitch flattening.
Z. FUNCTION BUTTON/LED 1: Press for "FX BYPASS" function to disable the effect in the active channel. In tuner mode, this red LED indicates a flattened pitch closer to correct tuning. This button also serves the Looper's "REC/DUB" function.
AA. DISPLAY WINDOW: Shows information about the selected mode and function.
BB. FUNCTION BUTTON/LED 2: Press repeatedly for "FX SELECT" function, cycling through effects on the control panel's EFFECTS DISPLAY (E). In tuner mode, this red LED indicates a sharpened pitch closer to correct tuning. This button also serves the Looper's "Play/STOP" function.
CC. FUNCTION BUTTON/LED 3: Controls time-based effect tempo (echo, delay, etc.) for both channels. Press at least twice at the desired speed to set delay time. The red LED above the button flashes in time. TAP TEMPO is global. Press and hold this button to enter hands-free tuner mode. The four red LEDs along the top of the pedal indicate pitch accuracy. This button also serves the Looper's "UNDO" function.
DD. CENTER TUNER LED: In tuner mode, this green LED indicates correct pitch.

Diagram Description: A visual representation of the footswitch pedal with labeled buttons: MODE, FX BYPASS, FX SELECT, TAP/TEMPO, LOOPER (REC/DUB, PLAY/STOP, UNDO), and MODE LED, FUNCTION BUTTON/LED 1, FUNCTION BUTTON/LED 2, FUNCTION BUTTON/LED 3, DISPLAY WINDOW, CENTER TUNER LED.

Looper

The Looper mode allows users to record loops up to 90 seconds long and overdub subsequent parts. Any number of overdubs can be layered, but only the last created overdub can be undone.

Looper functions can be operated manually using the LOOPER BUTTONS (K) on the control panel, or hands-free using the footswitch in looper mode.

Recording: Press the "REC/DUB" button on the control panel or the footswitch's FUNCTION BUTTON 1 (Z) after selecting Looper mode with the MODE BUTTON (Y). The "REC/DUB" button/LED will flash, and the DISPLAY WINDOW will show "REC". Play a passage of up to 90 seconds.
Playback and Overdubbing: Press the "PLAY/STOP" button (on the control panel or footswitch) to stop recording and start playback. The "PLAY/STOP" button/LED will illuminate, and the DISPLAY WINDOW will show "PLA". Press "PLAY/STOP" again to stop playback ("STP"). Alternatively, press "REC/DUB" again to enter overdub mode ("DUB"). Overdubbing can be done during playback or after stopping. Continue overdubbing as needed. Press "PLAY/STOP" to play back all recorded parts.
Undo Function: While recording, playing, or stopping the initial passage, press the "UNDO" button (on the control panel or footswitch) to undo the recording. The recording will stop, and the DISPLAY WINDOW will show three dashes. If overdubs have been added, the UNDO function only applies to the most recent overdub.
Clearing Looper: To clear all looper content, press "PLAY/STOP" (once during playback, twice during recording/overdubbing) to stop recording. Then, press "REC/DUB" to start a new recording, effectively clearing the previous audio.

Looper Notes:

Recorded audio is not saved when the amplifier is turned off.
The looper output is mono; stereo effects are not produced.
The VOLUME control (B) does not affect the looper once a recording has been made.
The looper can be used on both channels; both inputs (A) are automatically mixed equally with their volume levels.

Bluetooth

Pairing your device with the amplifier for Bluetooth streaming:

Press and hold the PAIR button (G) for three seconds to activate pairing mode. The PAIR button will flash and then remain solid when the connection is successful (timeout is two minutes). The amplifier will automatically pair with the last connected device if available.
To connect, enable Bluetooth on your external device, scan for Bluetooth devices, and select "FENDER ACOUSTIC". Use your external device's volume control to set the Bluetooth volume level through the amplifier.
To disconnect or connect to a different device, disable Bluetooth on the mobile device or press and hold the PAIR button (G) for three seconds. The amplifier will return to pairing mode for two minutes.

Performance Tips: The amplifier streams audio only from the user's mobile device. Phone calls will not come through the amplifier, but streaming audio will mute when a call is received. To avoid such interruptions, enable airplane mode on your mobile device and manually enable Bluetooth.

Specifications

Detailed specifications for the Acoustic Junior, Acoustic Junior Go, and Acoustic SFX II models:

Feature	Acoustic Junior, Acoustic Junior Go	Acoustic SFX II
Type	PR 5724	PR 5725
Power Requirements	155 watts	300 watts (max)
Power Amp Output	35 watts (typical), 100 watts into 4Ω	49 watts (typical), 2 x 100 watts into 4Ω
Input Impedances	4.7MΩ (instrument), 18.2kΩ (mic), 18kΩ (aux)	4.7MΩ (instrument), 18.2kΩ (mic), 18kΩ (aux)
Input Sensitivity	40mVrms (instrument), 4mVrms (mic), 900mVrms (aux)	40mVrms (instrument), 4mVrms (mic), 900mVrms (aux)
Phantom Power	16V (XLR input)	16V (XLR input)
Tone Controls	Low: ±12dB @ 80Hz, Mid: ±12dB @ 700Hz, High: ±12dB @ 5kHz (shelving)	Low: ±12dB @ 80Hz, Mid: ±12dB @ 700Hz, High: ±12dB @ 5kHz (shelving)
Line Out	Max Level: +19.8dBu, Nominal Level: +4dBu (2x), Impedance: 600Ω (balanced)	Max Level: +19.8dBu, Nominal Level: +4dBu (2x), Impedance: 600Ω (balanced)
Speaker	8" speaker (4Ω) and compression tweeter	Front: 8" speaker (4Ω) and compression tweeter; Side: 6.5" speaker (8Ω)
Headphone Output	140mW into 16Ω/channel	140mW into 16Ω/channel
Battery (Acoustic Junior Go Only)	Rechargeable Lithium-ion. Charging time: 4 hours. Battery life: 5 hours (heavy use). Capacity remains >70% after 500 charge cycles.	N/A
Pedal	Optional MGT-4 four-button footswitch (PN 0994071000) with magnetic overlay.	Optional MGT-4 four-button footswitch (PN 0994071000) with magnetic overlay.
Dimensions (W x H x D)	15.71" (39.9 cm) x 12.02" (30.5 cm) x 9.4" (23.9 cm)	15.7" (39.9 cm) x 19.39" (49.2 cm) x 10.21" (25.9 cm)
Weight	Acoustic Junior: 15.7 lbs. (7.14 kg) Acoustic Junior Go: 17.1 lbs. (7.78 kg)	22 lbs. (9.98 kg)

Note: Product specifications are subject to change without prior notice.

Part Numbers and References

The following part numbers are listed for various regions:

Acoustic Junior:

2314300000 (120V, 60Hz) NA
2314301000 (110V, 60Hz) TW
2314303000 (240V, 50Hz) AU
2314304000 (230V, 50Hz) UK
2314305000 (220V, 50Hz) ARG
2314306000 (230V, 50Hz) EU
2314307000 (100V, 50/60Hz) JP
2314308000 (220V, 50Hz) CN
2314309000 (220V, 60Hz) ROK
2314313000 (240V, 50Hz) MA

Acoustic Junior Go:

2314400000 (120V, 60Hz) NA
2314401000 (110V, 60Hz) TW
2314403000 (240V, 50Hz) AU
2314404000 (230V, 50Hz) UK
2314405000 (220V, 50Hz) ARG
2314406000 (230V, 50Hz) EU
2314407000 (100V, 50/60Hz) JP
2314408000 (220V, 50Hz) CN
2314409000 (220V, 60Hz) ROK
2314413000 (240V, 50Hz) MA

Acoustic SFX II:

2314500000 (120V, 60Hz) NA
2314501000 (110V, 60Hz) TW
2314503000 (240V, 50Hz) AU
2314504000 (230V, 50Hz) UK
2314505000 (220V, 50Hz) ARG
2314506000 (230V, 50Hz) EU
2314507000 (100V, 50/60Hz) JP
2314508000 (220V, 50Hz) CN
2314509000 (220V, 60Hz) ROK
2314513000 (240V, 50Hz) MA

Manufacturer Information:

Made by Fender Musical Instruments Corp.
311 Cessna Circle
Corona, Calif. 92880 USA

Importer Information:

Imported by: Fender Ventas de México, S. de RL de CV
Calle Huerta #279, Int. A. overste El Naranjo. CP 22785. Ensenada, Baja California, México.

Customer Service: 01(800) 7887395, 01(800) 7887396, 01(800) 7889433

Part Number: US+5 PN 7719919000 rev. c

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