Soundstream MC.500 User manual

MC 500
Five Hundred Watt
Multiple-Channel
Amplifier
P

.
Thank you for purchasing a Soundstream amplifier. You now own the finest high
power amplifier available, a precision component capable of audiophile-quality
performance.
CONTENTS
Wiring diagram
3
Design feature
4
Installation
5
Power connections
6
Remote power-on connection 7
LED power indicators
a
Selecting operating mode
a
Input connections
9
Output connections
10
Optimizing for speaker impedance
11
Input level adjustment
11
Linear Subwoofer Extension
12
Protection circuits
13
Service
13
Specifcations
14

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Figure I2Channel Opmztian
Flgun 2 3.Channel OperatIm
I
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DESI6U FEATURES
The Soundstream MC500 is the ultimate amplifier for high-power automotive
applications.
The MC500 is conservatively rated at 500 watts into 4 ohms. This power can
be divided into four channels (4 x 125 watts.), three channels (2 x125 watts,
1 x 250 watts), or stereo (2 x 250 watts).
Each output device is individually
rated at 125 watts, and there are 24 discrete output devices in the MC500, for
a total of 3 kilowatts of device capability. With such reserves and no current
limiting, the MC500 operates without strain even at maximum output. Power,
ground, and speaker connectors are rated to handle up to 80 amps and up to
6 gauge wire.
The MC 500 incorporates a unique protection system that prevents thermal
overload without the need for a fan. Should the unit approach an overheated
condition, dynamic headroom is reduced instead of a complete shutdown,
until normal operating temperature is reached. Then full output capacity is
restored. The entire process is automatic and inaudible. In the case of a
malfunction which should cause continued overheating, secondary thermosats
will shut down the amplifier in a conventional manner.
An especially useful feature of the MC500 is the Linear Subwoofer Extension
Circuit (LSE), which c.ompensates for the natural rolloff of most speakers and
extends bass as much as a full octave. LSE provides a
~linear boost of 6 dB/octave.
starting at a point which is continuously variable over the range 35-280 Hz.
A steep 24 dB/octave filter attenuates the signal below 20 Hz.
Only premium parts are used in the MC500, such as metal-film resistors, go!d-
plated input connectors, and imnersible sealed potentiometers. The case is
equipped with generous heat sinks. Input sensitivity is adjustable to match
any tuner/deck--the MC500 can even be used as a power booster.

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The MC500 features dual-monaural construction, with two fully independent soft
regulated pulse-width modulated power supplies that provide stability for low-
impedance reactive loads (down to 2 ohms/4 channel operation) and still allow
greater than 2 dB IHF dynamic headroom. All gain devices are biased by regu-
lated active current sources, so that even low-frequency performance is
unaffected by supply-line noise and temperature fluctuations.
INSTALLATION
Proper installation and adjustment will reward you with reliable operation and
optimum performance. Automotive sound system installations can be tricky,
especially for first timers. For this reason, you may want to consider using
a professional installer who has the tools and, more importantly. the experience,
to do the job right. If you decide to install your equipment yourself, we hope
that this manual will serve as a helpful guide.
Location and mounting
The first step in installation is thorough planning. Choose the location for
your amplifiercarefully. The amplifier should be located in either the passen-
ger compartment or the trunk, never in the engine compartment or in any outside
location exposed to dirt and moisture. Adequate ventilation is important; allow
enough space so that air can circulate around the heat sinks.
Make sure that the installed amplifier will not interfere with normal operation
of the car.
It is best not to locate the amplifier near your antenna. because
the switching power supply can interfere with AM reception.

Your amplifier should be mounted firmly to your car's sheet metal with the four
screws provided.
Use your amplifier as a template for making pencil-marks
where you intend to drill.
(Do not operate your drill through these mounting
holes.)
It's a good idea to bench test your system before mounting the components. If
you have a 12-volt power source, you can connect and test all the commponents
outside the car.
Or you can connect then inside the car before screwing them
down. Either way, connect the components exactly as you intend to in the final
installation: make all power connections last; test the system; then discon-
nect all power until the final installation is complete.
Wiring
Determine how your car's wiring is laid out, and run your wires in the same
locations when possible. Many passageways,wire-hooks, and strain relief devices
already exist in your car; take advantage of them. Keep all wiring inside the
car. Good standard audio practice suggests keeping signal wires short and
away from power lines. Wires can be run under carpet. If you drill a new
passage-hole through metal, make sure no burrs remain to scrape the wire; use
grommets as needed. All wires should be hidden; an exposed wire can inadver-
tently be pulled, causing disconnection or shorting. Wires should never be
under tension or subject to moisture. Use cable ties to bundle excess wire.
POWER CONNECTIONS
NOTE: Your amplifier can only be operated from a 12-VOLT NEGATIVE GROUND
electrical system. If your car was produced before 1970, or if you have any
doubts, make sure of the type of electrical system you have before making any
connections.

The MC500 will draw up to 70 amperes if used to its fullest capability. Deter-
mine the alternator rating of your car and the current consumption of the car's
other accessories. It may be necessary to upgrade the alternator or to install
a separate battery, especially in cold climates.
For power wiring, use 8-gauge wire or larger. (Smaller gauge numbers denote
larger wire.) The (PLUS 12V> terminal ((3, in the wiring diagram) should be
connected directly to the positive (+) terminal of your car battery. Install
two (2) 30 amp fuses (in parallel) in the line close to the battery terminal.
If you have more than one amplifier, each amplifier should be separately fused.
The (GROUND, terminal (2) should be connected directly to the automobile chassis
with 8-gauge wire or larger. Make this wire as short as possible to prevent
noise in the system.
A nearby bolt can serve as a ground terminal. Make sure
that the wire contacts bare metal, not coated metal or paint.
It is important
that the ground connection you select hav_
e minimal noise resistance to the
battery ground post (a maximum of 0.1 ohm).
REEIOTE POWER-ON CONNECTION
If your tuner/deck has a remote power-on control wire or terminal, connect it
to the <REMOTE> terminal
(1) on your amplifier. This is a control line, not a
power line, so small wire (18-20 gauge) is acceptable.
If your tuner/deck has no remote power-on control labeled as such, but has a
power antenna control,it may be possible to wire the power antenna control to
the (REMOTE) terminal.
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If your tuner/deck has neither a remote power-on control wire nor a usable
power antenna control, it will be necessary either to connect the <REMOTE>
terminal tu a +I2 volt source which is switched by the ignition key, or to con-
nect the (REMOTE> terminal to a constant t12 volt source through an on-off switch
you install in series with the ignition switch in a location accessible to
the driver.
LED PDUER INDICATORS
The two main channels of the MC500 (A and B) are completely independent, and
each has its own LED indicating power-on: (13) for main CHANNEL A, and (24) for
main CHANNEL 8. Since power should be disconnected during installation, these
LEDs should be dark until you are finished! Both LEDs will go out if the
power-line fuses are blown; if a chassis fuse is blown, only the LED for that _
amplifier section will go out.
SELECTIND OPERATING mDE
The five hundred watts available from the MC500 can be divided into two
channels (stereo) [Figure 11, three channels (stereo plus a single-channel
subwoofer) [Figure 21, or four channels (front and rear stereo; or stereo
bi-amp) [Figure 31.
To select any of these modes, remove the plug covers marked CHANNEL A and
CHANNEL B on the bottom of the amplifier switch.

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For two-channel operation, set both switches to <MONO>.
For three-channel operation, set one switch to <STEREO>
and the other to (MONO). Note carefully which
is which, because you must connect wires
accordingly.
For four-channel operation, set both switches to <STEREO>.
INPUT CONNECTIONS
Inputs to the amplifier attach by means of standard RCA-type jacks. The MC500
achieves a level of performance at which cable and connector quality is sig-
nificant; the jacks on your amplifier are gold plated, and we recommend premium
gold-plated plugs and high-quality shielded cable.
P In most cases, the signal source will be the preamp output jacks of a tuner/deck.
Some tuner/decks use preamp output connectors other than RCA jacks, in which
case you will need a special cable or adaptor available from your dealer.
If your tuner/deck has speaker outputs and no preamp outputs, you can use the
speaker outputs.
Wire RCA-type plugs to the ends of your tuner/deck's output
wires, making sure that you maintain consistent polarity in all channels.
If you have an equalizer or low-level crossover network(s) for bi-or tri-
amping, these components will be inserted between your tuner/deck and your
amplifier(s).
Refer to the manuals for these components for further details.
In 4-channel mode, all four input jacks <15), (16>, <26>, and (27) are active
for CHANNEL A left and right and CHANNEL B left and right, respectively.
In Z-channel mode, use oniy the "right" jack (16> for CHANNEL A, and only the
"right" jack (27) for CHANNEL E.

In 3-channel mode, use only rthe "right jack for whichever of main CHANNEL A
or CHANNEL B is operating in mono, and both jacks for the other main channel.
OUTPUT CONNECTIONS
Use high-quality loudspeaker cable for best results; use 14-gauge cable as
a minimum size.
In 4-channel mode, all four terminals <6), (7>, <El), and (9) are active for
main CHANNEL A, and all four terminals t17), (18>, <19>, and (20) are active
for main CHANNEL 8.
In 2-channel mode, use only the
"+" terminals (17) and (20) for CHANNEL 6.
The '+ right" terminals (9) and (20) have positive polarity in this mode.
In 3-channel mode, use only the I'+" terminals for whichever of main CHANNEL A
or CHANNEL B is operating in mono, and all four terminals for the other main
channel.
The terminals on your loudspeakers are marked for polarity, and loudspeaker wire
is coded by color or by markings on the jacket. Be sure to connect the left
and right channels with the same polarity. Loudspeaker manufacturers are not
consistent in their polarity markings, so if you have loudspeakers of different
types connected to the same amplifier terminal, verify correct polarity by ear.
The correct polarity produces the most bass; incorrect polarity produces
less bass and a strangely dislocated sound image on mono material.
If you have more than one amplifier: for each amplifier and its loudspeakers.
the left and right channels must always be wired with the same polarity. But
from one amplifier to the next, correct polarity may be the same, or it may be