Owner's Manual and Installation Guide 5/3 Channel Power Amplifiers 255, 355, 555
RUBITM
(Rapid-Use Branched
jmpulse)
This new proprietary power
-
-
supply topology eliminates “power sags” during low frequency repro-
duction by rapidly increasing the duty cycle, stabilizing the power sup-
ply and allowing it to deliver the power required when reproducing low
frequencies. Also, greater reserve gate power is stored for low volt-
age situations that occur during extreme conditions.
STACTTM
(STabilized
Apex
Qrrent
_Topology)
Reduces power sup-
ply stress by 50%. Typical designs degrade the stereo image due to
phase reversal of even-order harmonic distortion that occurs between
the inverted channels. In the STACT design, inversion is done at the
power amplifier drive stage. Since the fully symmetrical power ampli-
fier produces no even-harmonic distortion itself and all preamplifier
circuitry is run completely in-phase, no even harmonic distortion phase
reversal occurs.
TridentTM
Protection
Topology
provides three types of protection:
1. Output protection against short circuits or improper loads.
2.
Ground fault detection: Shuts down the amplifier when
a
significant
voltage
(~5
Volts) fluctuation occurs between electrical (turn-on lead)
and battery ground.
3. Thermal Protection: Puts the amplifier into thermal rollback or shuts
the amplifier down in extreme thermal conditions.
Hawkins Bass Control
provides a focused subwoofer boost (O-9
dB
at 45 Hz) and routes otherwise wasted amplifier power back to the
audible bandwidth.
Harmonic Bass Alignment
TM
The 2nd and 3rd order harmonic peaks
are critically aligned to fundamental peaks at low frequencies. This
produces tighter, more accurate bass reproduction.
Drive Delay
llTM
Amplifier section powers up 2 to 3 seconds after the
power supply eliminating turn-on pops. Turn off process is reversed:
Amplifier section turns off first, followed by the power supply.
Dynamically Optimized
Power Grid
TM
Power grid is evenly distrib-
uted between primary and secondary power supplies, providing
greater
dynamics and improved RF filtering.
4
ChassisinkTM
All transistors are ideally located and sandwiched be-
tween the circuit board and the heatsink to provide cool efficient ampli-
fier operation.
Differentially Balance RCA Input
eliminates ground loop related noise
in the audio path.
Continuously Variable Crossover Networks (355
&
555):
12 dB/
Octave 2-way
highpass
crossover, variable from 65 to 220 Hz and 24
dB/Octave
lowpass
crossovers variable from 30 to 120 Hz. 555 on/y
-
12 dB/Octave 3-way crossover which can be selected for mid-bass
(65 to 500 Hz) or midrange (65 to 4,000 Hz) operation.
Built-in Staggered S.I.P. Crossover Network (255)
Built-in two-way
electronic
crossover is designed to send high pass information to
channels 1-4 of the amplifier and send low pass to channel 5 of the
amplifier.
12dB/oct
Highpass
and
Lowpass
crossovers.
Flexible
Stereo1
Input Level Control allows 200
mV
to 5 V input
sensitivity.
Symmetrical Discrete Balanced Class A Drive Boards Auto-ad-
just for linear performance while driving low impedance loads.
Removable Front Spoiler allows for stealth installation of RCA,
Speaker and Power wiring.