Filter
Top Products
Chapter 3: Operation
RA150/300/500 Reference Manual 23
USING THE RA150 AS A
HEADPHONE AMPLIFIER
The RA150 is particularly suited for use driving
high-impedance headphones in studio applica-
tions. However, the power is considerably greater
than that provided by most "headphone
amplifiers", which are often rated at 1 watt or
below.
Due to the high efficiency of headphones
and the power of the amplifier, serious
hearing damage may result from misuse
of this product. Exercise caution
regarding sound levels.
Keep the following in mind:
• Many studio-quality headphones feature
impedances of 600 ohms or greater. This
means that many headphones of the same
type may be plugged in parallel to the
output of the RA150/300/500 before the 4-
ohm limit is reached.
• If you plug in a headphone with a lower 8-
ohm impedance, it will be dramatically
higher in level than the others, and the
high-impedance headphones may drop to
inaudibility.
• The TRS 1/4" jack used in headphones will
tie together the grounds of the left and
right amplifier channels. Use caution and
only connect or disconnect head-phones
when the amplifier is powered off.
• Keep the RA150's front panel volume
controls at a very low level and the controls
of the headphone send near maximum.
This will prevent accidental "blasting"
during a session.
CHOOSING THE CORRECT
SPEAKERS
Near-field monitoring through “reference”
speakers has become the preferred way to
monitor and mix music. With near-field
monitoring, small speakers are placed so that
they are a few feet from the engineer’s ears. As a
result, room acoustics become less important
since the primary acoustic interaction involves
direct sound from the speakers rather than
reflected sounds from the room. Since few home
and project studios have good acoustics, near-
field monitors can provide realistic monitoring in
a small space at relatively low levels.
Near-field monitors offer other advantages
compared to large studio speakers, including
smaller size, lower cost, and easier
transportability to other studios for reference
purpose.
Because of its moderate power rating, excellent
fidelity, and lack of a noise-generating fan, the
RA150/300/500 “Reference Amplifier” excels in
driving reference near-field monitor speakers in
smaller studios. However, you should choose
speakers that can handle the power the
RA150/300/500 can generate. Speaker wattage
ratings are often confusing, and standards by
which ratings are obtained vary from
manufacturer to manufacturer. If a speaker can
handle 100 watts RMS continuous power, it
should be able to handle the RA150/300/500.
However, under conditions of clipping or other
abuse of the RA150/300/500, damage to speakers
is possible. For best results, use speakers
designed for medium- to high-power
applications.