Asl intercom ROXX 301 User Manual
RoXX-Series
301 Personal Headphone Amplifier / Line Checker Manual
The RoXX-Series 301 by ASL is a versatile professional stereo headphone amplifier for
personal and portable use. The unit is battery powered and accepts all commonly used
audio signals: balanced and unbalanced signals at microphone, line or speaker level.
This Personal Headphone Amplifier has been designed with great precision. However, designing equipment like this
is always a matter of finding compromises between: max. gain, noise, max. output power, distortion, power
consumption, flexibility, mechanical aspects, costs etc. The starting point of this design was to make a versatile unit,
which can be used for many purposes in different circumstances, with long battery life and as little as possible
controls. We hope we managed to meet your requirements. Read this user manual first.
Applications for the ASL RoXX - Series 301 Personal Headphone Amplifier
Practicing through headphones Checking microphone signals
An electronic instrument (guitar, keyboard) or a CD Very usefull to, for instance, boom operators.
player can be connected to the (stereo) Jack input(s),
and a dynamic microphone can be connected to the
XLR input. These signals can be mixed to the stereo
headphone output to practice. Even two headphones
can be connected in order to allow a singer to practice
together with an instrumentalist.
Creating a monitoring system for studio or on
stage use
An output of the mixing console can be connected to
the stereo input of the PHA, and a microphone or
instrument can be connected to the XLR input with a
loop through to a mixing console input. The performer
can make his own mix between his own voice /
instrument and the signal from the mixing console.
Headphones can be used in a studio, ear plugs on
stage.
Boosting a headphone output
Whenever the headphone output power of any equipment is not sufficient, the Personal Headphone Amplifier can be connected to that headphone output.
The output power of the PHA will be high enough for
most circumstances/purposes.
Trouble shooting
A sound engineer can check lines, microphones or
outputs, to locate signals or to solve problems.
Routing two headphone outputs to one headset
For instance the monitor outputs of two mixing consoles, or the monitor output of a mixing console and
an intercom signal.
Setting up a (battery powered) two station intercom system
A dynamic (headset)microphone can be connected to
the XLR input of each of the two PHA’s. The loop
through XLR’s are interconnected. The two users can
hear eachother (and themselves) through the connected head(set)phones. Two identical microphones
need to be used, and the microphone signals are
summed by there output resistance.
Sending an audio signal to many headphones
Two headphones can be connected to one PHA.
Personal headphone amps can be interconnected
using the loop through connectors.
More applications to be discovered by yourself!
A S L C O M M U N I C A T I O N S Y S T E M S RoXX-Series 301 Manual
FRONT PANEL
1 Power switch
With this switch the unit is turned on and off.
5 -20dB switch
With this switch the gain of the unbalanced inputs
can be reduced by 20 dB for monitoring speaker or
2 Power-on LED indicator
This LED illuminates green when the unit is
switched on.
high level line signals.
In the normal position the input impedance of the
unbalanced inputs is very high (1M Ohms),
enabling the monitoring of electric guitar signals (or
* When the Personal Headphone Amplifier is
other pick-ups).
prepared for charging Ni-MH batteries within the
unit, this LED also indicates fast charging of the
cells. During fast charging, while the unit is
switched off, this LED lights up burns red. During
6 Stereo/mono switch
In mono position a stereo signal on the unbalanced
input(s) is made mono.
fast charging, while the unit is switched on, this
LED lights up orange.
7 Unbalanced input Volume control
With this knob the volume of the unbalanced input
3 Stereo headphone 3,5mm mini jack
signal can be controlled
Two headphones can be connected to this
headphone amplifier at the same time. A headpone
with a 3,5mm mini jack can be plugged in this
connector.
8 Balance control
With this knob the left / right balance of the
unbalanced input signal can be adjusted.
Both high and low impedance headphones can be
used (when using 2 headphones at the same time,
9 Mic / Line switch
use headphones of the same type). The internal With this switch the sensitivity of the balanced input
power amplifiers are short-circuit and overload can be selected.
protected.
10 Balanced input Volume control
4 Stereo headphone jack 1/4”
With this knob the volume of the balanced input
A headphone with a 1/4” jack can be plugged in signal can be controlled.
this connector.
11 Pan control
With this knob the left / right panning of the
balanced input signal can be adjusted.
A S L C O M M U N I C A T I O N S Y S T E M S RoXX-Series 301 Manual
REAR PANEL
12 Balanced input + loop thru XLR’s
These XLR-3 female and male connector are
paralleled and are the input & loop thru for a
balanced signal (mic. or line level).
13 Mono left / stereo input jack
This 1/4" jack connector is the input of the left
signal of a stereo signal when a mono jack is used
(input 14 is the right input), or the left and right
signals when a stereo jack is used (input 14 is not
used). It accepts signals of line or speaker level.
14 Mono right / mono input jack
When no signal is connected to the left jack input
(13), the mono signal on this input is sent to the left
and right cans of the headphone. When there is
also a mono signal connected to the left jack input
(13) the signal on this input is sent only to the right
input (input 13 is the left input). It accepts signals of
line or speaker level.
15 Stereo loop thru connector
This jack connector is always configured as a
stereo loop thru for the signals connected to the
unbalanced inputs 13 and/or 14.
When a stereo signal is connected to input 13 this
connector provides a stereo link. When mono left
and mono right signals are connected to inputs 13
and 14, this connector outputs those signals as a
stereo signal (left=tip, right=ring). When a mono
signal is connected to input 14, this connector
outputs the mono signal (on tip and ring). This
connector is especially useful for connecting
multiple headphone amplifiers to one source.
SIDE PANEL
16 DC adaptor input
An external DC adaptor can be used to power the
RoXX-Series 301. The internal batteries will
automatically be switched off. The unit accepts DC
voltages from 9 V to 24 V.
* When the Personal Headphone Amplifier is
prepared for charging Ni-MH batteries within the
unit, the external DC voltage can range from 12 V
to 18 V. The adaptor must be capable of delivering
a current of at least 700 mA.
17 Internal battery compartment
Accepts 4 AA-type 1.5 volt batteries or 1.2 volt
rechargeable cells.
The Personal Headphone Amplifier can be
modified so that Ni-MH cells can be charged in the
unit. Consult your distributor for more information
18 Beltclip
Powering the Personal Headphone Amplifier
Battery Operation Open the battery compartment on the side of the unit
A S L C O M M U N I C A T I O N S Y S T E M S RoXX-Series 301 Manual
Loading...