Mass-Kobo 404 A - User Manual

model404 A/S
Full Balanced Portable Headphone Amplifier
User’s Manual
HOW TO USE
<Battery Loading>
Slide open the latter half of the body and load 6 (six) AAA batteries.
Please set the polarity of the batteries right carefully.
The circuit in the amplifier may be broken by the wrongly placed batteries.
<Battery Replacing>
Please replace the batteries with new ones when the Power Indicator turns red.
Though you may use the amplifier for a while after the indicator turns red, replacing batteries
immediately is recommended.
The Power Indicator will turn red as the voltage goes down below 6.5V.
<Power by USB>
You can use the amplifier by the power provided by USB.
Use any USB charger or mobile battery that can provide more than 1A.
Use thicker USB cables; the voltage may be not enough with thinner cables.
The Power Indicator will turn red as the voltage goes down below 4.6V in this case.
R- L- R+ L+
For Line-in by the
Standard Balanced Plug
3.5mm
For the balanced
plug of AK series
2.5mm
R-R+L+L-
LR
G
1
23
4
L-
R+
R-
L+
USB Charging Connector
Balanced Line-in
Balanced Headphone out
for Balanced Armature
Balanced
Headphone
out
Unbalanced
Headphone out
Unbalanced
Line-in
Power
Indicator
Input Selector
Volume Control
Power
Switch
made in Fujieda JAPAN
ON
POWER
UNBAL
BAL
INPUT
UNBAL INUNBAL HP
Headphone Amp. model４０４
BALANCE HP
BAL-IEM
BAL-IN
EXT POWER

Summary

How to Use

Battery Loading

Instructions for opening the body and inserting six AAA batteries with correct polarity to avoid damage.

Battery Replacing

Guidance on replacing batteries when the Power Indicator turns red, indicating low voltage (below 6.5V).

Power by USB

Details on using USB power with chargers/batteries rated over 1A and using thicker USB cables for sufficient voltage.

Safety Warnings

General Handling Precautions

Warnings against dismantling, dropping, hitting, or using incorrect batteries to prevent injury or damage.

Connection and Usage Safety

Advice on handling plugs gently, connecting ports correctly, and avoiding induction noise with mixed outputs.

Output Port Restrictions

Crucial warning not to connect headphones or earphones to both balanced and unbalanced outputs simultaneously.

Warranty Information

Warranty Coverage and Repair

Details the one-year warranty for defects and the necessity of sending the User's Registration Card.

Warranty Exclusions

Outlines damages not covered by warranty, such as accidents, misuse, or external causes.

Refusal of Repair

States the right to refuse repair for units that have lost their original form or are excessively damaged.

Specifications

Mass-Kobo 404 A Specifications

General

Brand	Mass-Kobo
Model	404 A
Category	Amplifier
Language	English