Overview: The Marantz PM8004 is a two-channel integrated
amplifier rated at 70 watts x 2 into 8-ohms and 100 watts x 2 into 4-ohms. In
both the pre-amp and power amp sections, the PM8004 uses fully-discrete, high
speed current feedback circuits for minimal phase shift and better detail
resolution. Even the phono input is a fully discrete, constant-current design
optimized for moving magnet phono cartridges. Marantz's HDAM SA3 (Hyper Dynamic
Amplifier Module) performs critical stage-to-stage signal transfers. Five of the
inputs (all but CD) share a buffer circuit to minimize unwanted interactions
between the source and amp. The CD input has a separate buffer for even better
isolation. The record outs are also buffered for enhanced recording clarity.
Chassis Construction: The amplifier's chassis uses a triple-layer
bottom plate to insure long-term alignment and vibration control. The unit's
front panel uses a combination of aluminum and glass-reinforced resin to create
a distinctive three dimensional appearance. Indirect reflecting blue LEDs indicate
the input selection.
HDAM (High Definition Amplifier Module): Marantz uses HDAMs
instead of standard op-amps, resulting in a more dynamic sound with less susceptibility
to radiated noise, heat, and vibration. The V/I converter circuit, the key
block of the current-feedback pre-amplifier and power amplifier, is equivalent to
the HDAM-SA3 amp-module developed for higher-grade Marantz components.
Momentary-Current Supply: The PM8004's main amp has the
capability to momentarily pass 25 amps or more, providing high-powered drive
to the speakers.
Short Power Line: To improve the momentary-current supply,
the large current line connections are as short as possible, while remaining
symmetrical. The individual power supply segments are located on the same heat
sinks as the output transistors for quicker response to musical transients.
Discrete Current-Feedback Phono Equalizer: The PM8004 provides
an all-discrete, current-feedback phono equalizer optimized for moving magnet (MM)
Double-Shielded Toroidal Transformer: This unit is equipped
with a toroidal power transformer to minimize vibration and leakage flux, which
affects sound quality. The outside is double-shielded, using a core ring and a
Power Amp Direct: The PM8004 can be used as just an
amplifier, with a separate pre-amp. Connecting the outboard pre-amp's output to
the Power Amp Direct In input bypasses the PM8004's input selector, balance,
tone, and volume controls. In this configuration the amp's signal to noise ratio
is 125 dB.
Auto Standby: With the Auto Standby Mode turned on this unit
will enter standby mode after approximately 30 minutes (continuous) of no output
from the speakers or headphones.
Master Power: A mechanical switch turns the main power on/off.
When off, the remote has no effect. When on, the remote can be used to switch between
on and standby.
Input Selector: A rotary knob on the front panel is used to
select the input source (Phono, CD, Tuner, AUX/DVD, Recorder 1, Recorder 2,).
Using the remote you can select the input directly.
Bass: A rotary knob adjusts the bass output, +/-10 dB at
Midrange: A rotary knob adjusts the midrange output, +/-6 dB
at 900 Hz.
Treble: A rotary knob to adjust the treble output, +/-10 dB
at 15 kHz.
Balance: A rotary knob adjusts the left/right balance.
Speakers: Two buttons allow you to independently select
speakers A and B. When
using headphones turn them both off; they are not automatically muted.
Power Amp Direct: To engage the Power Amp Direct feature
hold this button for three seconds. This bypasses the PM8004's input selector,
balance, tone, and volume controls.
Source Direct: When source direct is engaged the bass,
and balance circuits are bypassed.
Remote Control: The supplied wireless remote will control the
PM8004 and Marantz CD players, DVD players, tuners, and tape decks.
Speakers: The speaker system A and system B outputs are binding
posts. They are not 5-way posts, but will accept single banana plugs, pin connectors,
and bare wire up to 10 gauge.
Line Inputs: The CD, Tuner, and Aux/DVD inputs have stereo RCA
Recorder: Recorder 1 and Recorder 2 each have stereo RCA inputs
Phono: The stereo RCA phono input will accept moving magnet
cartridges. There is a ground terminal beside the phono input.
Pre Out: Stereo RCA outputs feed a powered subwoofer or another
Power Amp Direct In: Stereo RCA inputs feed the amplifier
section directly from an outboard pre-amp when using the Power Amp Direct
Remote control: An RCA Remote Control input and output are used with
other compatible Marantz components; CD player, DVD
player, Tuner, etc. This allows the included remote to control the other Marantz
Headphone: A standard 1/4" headphone jack is on the front
panel. The speaker outputs are not automatically muted when you plug in headphones
so the speakers must be manually turned off.