If you have an amp that sounds great when
you crank it up but it’s just too loud for most
playing situations, you’ll want to know about
the new Aracom Power Rox PRX 150-Pro
amp attenuator. Designed for use with tube
amps, this unit lets you reduce the level of a
fully cranked head or combo.
Construction
The PRX 150-Pro is housed in a black
anodized-aluminum case with an amp-style
strap handle, and it looks all business. When
I unpacked my review unit, the vented front,
side, and rear panels caught my eye. They
are, of course, for cooling, but they give
the box a striking, industrial vibe. A passive
device, the PRX 150-Pro requires no AC
power for operation.
Two front panel knobs—Step Attenuation
and Variable—let you control your amp’s output
level. Step Attenuation has six discrete
settings labeled A-F. Settings A-E reduce
the level in 3 dB increments. Switching to
position F engages the Variable knob, which
lets you further attenuate the output by
as much as 16 dB. The unit can handle a
150-watt input signal and our review model
provided an overall cut of 30 dB (which
effectively takes a 100-watt amp down to
0.5 watts—3% of the amp’s power rating).
However, Aracom informs us that the latest
PRX 150-Pros can attenuate up to 40 dB—
which can take a 150-watt amp down to .015
of a watt.
The PRX 150-Pro’s magic really happens at
the back panel. The input—where you plug
in your amp’s speaker output—offers 2-, 4-,
8,- and 16-ohm settings, and that’s what sets
the PRX apart from most other attenuation
devices. Having a variable input selector lets
you use the PRX with different amps with various
fixed output impedances. You don’t have
to purchase separate units to accommodate,
say, a Fender Super Reverb and a Marshall
JCM900. And if your amp offers selectable
output impedance, you can explore the
different taps on the output section, which
can alter the amp’s tone and feel.
The Aracom’s own output impedance is also
variable, and you can set this independently
of the unit’s input impedance. You can switch
the PRX 150-Pro’s parallel output jacks to
2, 4, 6, 8, and 16 ohms, which gives you
complete flexibility to mix and match amps
and speaker cabs with dissimilar impedance
ratings. Very flexible. Further, a true-bypass
switch on the back panel allows you to bring
the PRX in and out of the circuit.