The main amplifier PCB uses through-hole parts entirely. All resistors are high-tolerance parts, and film capacitors are used where it counts in order to keep the signal path clean. The input/DSP daughter board is entirely surface-mount except for the RCA input and remote level control connectors. The daughter board connects to the main board through a 26-pin header and is held in place by no less than five screws.
From the terminal block, the +12V goes through a pair of ATC 20A fuses and a heavy-gauge air-core inductor hash filter. There are actually two separate power supplies, both managed by separate TL494CN PWM controllers running at approximately 30kHz. One supplies the heavy lifting of the amplification itself while the other provides a stable power source for the digital stuff. The Litz-wound transformer for the "big" side is switched through two pairs of IRFZ44's capable of 150 watts each, for a total of 600-watt capability. There is a total of 4400F filtering on the primary side and 4000f on the secondary, in addition to a cap/inductor filter on each of the positive and negative rails. The outputs consist of two complementary pairs of TO-247 size devices for each channel at the business end of a Darlington-type circuit, each pair handling up to 160 watts at 25 degrees Celsius. That's 640 watts total, so the amp should easily be capable of delivering the promised 400 watts of dynamic power.
The two pairs of RCAs are paralleled together, in essence no more than a built-in "Y" connector. The outputs (PAST(tm)) are exactly the same as the inputs with no buffering or crossover filtering.
The brains of this amplifier are on the Input/DSP board. Even the input gain is adjusted through the digital interface. The input signal is buffered through low-noise op-amps and is then sucked into the digital domain by analog-to-digital converters (ADCs) where it exists as nothing more than a string of numbers. The primary component is a DSP chip that facilitates the parametric equalizer, crossovers, gain and compression by manipulation of the string of numbers. Think of the chip as a calculator performing various calculations on the "numbers" that make up the signal path. The modified digital number string is then converted back to analog by, you guessed it, a digital-to-analog converter, and is sent to the amplifier's output section. There is an 8-bit Micro controller with programmable flash memory that holds the instructions for the DSP chip, a vacuum fluorescent display and driver, and an array of push-button switches so you can tell it all what to do.
PerformanceFrequency response measured 20Hz to 23.5kHz, a little better than the 20Hz to 20kHz that Kicker states. There is a very pronounced roll-off at 23.5kHz (see frequency response graph) that is probably a result of the digital signal processing.