SERIES AND PARALLEL WIRING
REFERENCE
Class A
5.0 & 10.0
Power Amplifiers
2-4 ohm drivers in parallel
= 2 ohms
OWNERS MANUAL
AND
INSTALLATION GUIDE
4-4 ohm drivers in parallel
=1 ohm
2-4 ohm drivers in series
= 8 ohms
SOUNDSTREAM TECHNOLOGIES
120 Blue Ravine Road Folsom California 95630 USA
ph 916.351.1288 fax 916.351.0414
rev B - 4.17.96
PROTECTION CIRCUITRY
TABLE OF CONTENTS
Your REFERENCE Class A amplifier is protected against both overheating and
short circuits by means of the following circuits:
· Main power supply fuses
· Smart Power Supply Thermal Rollback activating at 85°C.
· A fail-safe thermal protection circuit activating at 95°C.
Design Features................................................................. 4 - 5
AIRBASS™............................................................................. 5
Reference Class A 5.0 Diagram......................................... 6 - 7
Reference Class A 10.0 Diagram....................................... 8 - 9
Selecting Input Modes........................................................... 10
Balanced / Unbalanced Input................................................ 11
Wiring & Wiring Diagram................................................ 12 - 13
Installation and Mounting ...................................................... 14
Level Setting ......................................................................... 15
LSE.Q Theory and Use.................................................. 16 - 17
Protection Circuitry & Troubleshooting.................................. 18
Service.................................................................................. 19
Specifications........................................................................ 19
Your amplifier also incorporates an innovative Fault Diagnosis system that
NOTE: If you experience blown main power supply fuses, DO NOT increase
values beyond the original fuse value! Doing so will void your warranty and may
damage your amplifier.
If you blow fuses with the REFERENCE Class A
amplifiers, it is likely that the amplifier is seeing a dead short, either in the speaker
TROUBLESHOOTING
PROBLEM
CAUSE
No sound and power LED is
not lit
· No power or ground at amp
· No remote turn-on signal
· Blown fuse near battery
No sound, a power LED is lit,
and the AIRBASS™ option
has not been added.
· No signal input
· The AIRBASS™ switch is in the "IN" posi-
tion. Move it to the "OUT" position
Fault LED is lit
· Amp power supply fuse is blown or miss-
ing
Repeatedly blown amp fuse,
frequent activation of Smart
Power Supply Circuit
· Speaker or leads may be shorted
· Verify adequate amplifier ventilation
Not enough input sensitivity
while using Balanced input
· Be sure both Left and Right Input Signal
Switches are set to the "BAL" position
Left and Right Input Over-
load indicators lighting
· Input signal level is too high - readjust in-
put gains, or select the 0.5-5V input signal
level range
Alternator whine while using
Unbalanced RCA inputs
· Make sure the Right Input Signal Switch is
in the "UNBAL" position.
· Try the Left Input Signal Switch in the
"BAL" and "UNBAL" position: leave the
switch in the quietest position. This will
3
not effect the performance of the amplifier.
LSE.Q THEORY AND USE (continued)
8.0
DESIGN FEATURES
This is due to the loss of any
appreciable resistive air mass. At
7.0
· Pure Class A Output Topology for the utmost in musicality and definitive
power output. Soundstream's unique design allows the Class A amplifiers to
deliver incomparable sonics or, when operated at lower impedances, to
provide phenomenal amounts of power.
6.0
5.0
frequencies below resonance, the
Xd
4.0
woofer starts to behave as if it were (mM)
3.0
2.0
mounted in “free-air”. If we wish to
1.0
· Uncompromising Design and Construction including mil-spec glass
epoxy circuit boards and high current custom gold-plated solid brass
connections that will accept up to 4 gauge power/ground wire.
improve the performance of
a
0.0
10
Frequency (Hz)
50
100
200
vented system, we should remove
these unwanted signals from our
system. These can be removed by
adding a subsonic filter. Figure 5 shows the effectiveness of LSE.Q on
woofer excursion. Woofer travel is 7.5 mm at 10 Hz, with LSE.Q
properly adjusted, this excursion can be
reduced to less than 1 mm. This is of great
benefit to lowering woofer distortion and
increasing output.
FIG. 5 Limited Excursion
· Quad Factor™ Circuitry - Soundstream’s newest power supply design
allows the Class A amplifiers to make four times the power when going from
a 4 ohm stereo load to a 2 ohm stereo load, and again when going from a 2
ohm stereo to a 1/2 ohm stereo load!
· Coherent StereoTM/Mixed Mono selection for either “pure” stereo operation
or mixed mono for simultaneous stereo and mono.
· ChassisinkTM Darlington Power Array - Soundstream’s “overbuilding” of
the output section incorporates multiple output transistors instead of a few
for faster, stronger power delivery. The transistors are sandwiched between
the circuit board and the heatsink in a design called ChassisinkTM to ensure
cool, efficient amplifier operation.
Adjustment
An easy method of optimizing your existing
subwoofer enclosure with LSE.Q's “Hz” control
is as follows.
1Adjust frequency and boost control to full
CCW position. (See figure 6)
· PowerGrid Power Supply Design - All power supply components are
located near one another, connected by thick, wide PCB traces, which
ensures rapid, high current delivery. The entire power supply is isolated on
one side of the circuit board while the audio stage is located opposite it,
guaranteeing minimal noise.
FIG. 6 LSE.Q Setting
2While listening to music with strong bass content at a moderate level,
slowly adjust frequency control clockwise. Listen for a reduction of
bass response. Now, rotate
10
· Ultra-Low ESR Capacitance Bank - Multiple small input power capacitors
are used to provide a lower ESR (Equivalent Series Resistance), which
means more power in and out faster.
frequency control slightly
backwards. This serves the purpose
5
0
of removing the “subsonic” bass
energy.
Soundstream’s LSE.Q contains the
-5
dB
-10
· Smart Thermal Rollback - Most amplifiers shut off when they get too hot.
In the unlikely event the REFERENCE Class A amplifier reaches 85° C, it will
gradually roll back its average power (without affecting the dynamics). Once
the amplifier has cooled off, it returns to full power output. If overheating
should continue, a second thermal sensing protection circuit will shut off the
amplifier if the heatsink reaches 95° C.
-15
-20
same type of circuit with the added
benefit of infinite adjustability. Our
“Q” and “Hz” control can provide
virtually any combination of boost
-25
-30
10
Frequency (Hz)
50
100
200
FIG. 7 Various Settings
· Fault Monitor LED on the top panel notifies you of blown power supply
fuses.
NOTE: The LSE.Q circuit on the Class A 10.0 can be defeated for flat
operation down to 20 Hz by placing the LSE.Q switch in the "OUT"
position. You may wish to use this option to achieve a higher S/N Ratio
when using ultra-high efficiency speakers, such as compression
· 1/4 ohm Drive Ability - The REFERENCE Class A amplifiers are designed
to drive virtually any load—all the way down to 1/4 ohm stereo (1/2 ohm
mono).
· Dual Discrete Class A Drive Stages - Over six times the drive current of
4
17
LSE.Q THEORY AND USE (Class A 10.0)
LSE.Q is a unique subwoofer control circuit
most amplifiers in the Class A 5.0, and over twelve times in the Class A
10.0! More drive current maintains the amplifiers' performance into low
impedance loads.
included
with
the
SOUNDSTREAM
REFERENCE Class A 10.0 amplifier. It is
capable of removing subsonic energy in program
material. The circuit consists of two controls.
One adjusts the frequency of operation and the
other adjusts the range of boost. With both
controls adjusted fully counter-clockwise, no
boost is applied and the amplifier is flat in
response down to 30 Hz.
· Drive DelayTM Muted Turn-on/off Circuit - A unique circuit which
completely eliminates any amplifier-related turn-on/off noises.
· Flexible Dual Input Level Sensitivity accepts 2 voltage ranges; from 200
mV to 2.0 V and from 500 mV to 5.0 V, permitting maximum output from the
amplifier with virtually any source unit.
FIG. 1 LSE.Q
· Differential Balanced Input Design for added immunity to noise caused by
component and vehicle electrical system interaction when using Unbalanced
RCA inputs.
The frequency control (Hz) adjusts the starting point of the subsonic
10
filter. This high pass filter can be
adjusted from 30 Hz up to a
maximum of 60 Hz. This control
is useful for setting the lowest
frequency that your subwoofer will
see. (See figure 1)
5
Q=2.8
0
· True Balanced Input for professional-quality performance and noise
cancellation. The 6-pin din plug carries (+) and (-) Signal information for Left
and Right channels, audio ground, and ±15 Vdc to operate the Soundstream
BLT Balanced Line Transmitter.
-5
dB
Q=0.707
-10
-15
-20
-25
-30
The
amount of boost applied at the set
frequency. This is adjustable
Q
control adjusts the
10
Frequency (Hz)
50
100
200
FIG. 2 Variable “Q”
10
5
from .707 (flat) to 2.8 (+9 dB).
(See figure 2)
AIRBASS™ ACCESSORY OPTION
0
-5
When the Q is set to .707
(Butterworth), LSE.Q acts as a dB
sub-sonic filter only. (See figure
3)
Soundstream's new AIRBASS™ feature can be added to the REFERENCE
Class A amplifiers. This feature allows wireless RF remote control level
adjustment of the amplifier.
-10
-15
-20
-25
-30
NOTE: The AIRBASS™ accessory is intended to be used only while the
10
Frequency (Hz)
50
100
200
The simple act of removing the
signal below the vented tuning
frequency can improve system
REFERENCE Class A amplifiers are driving subwoofers.
When the
FIG. 3 Variable High Pass
AIRBASS™ accessory is added to a REFERENCE Class A amplifier, it
automatically configures the amplifier into Bridged Mono mode. (The Coherent
Stereo / Mixed Mono / Bridged Mono switch is bypassed.) Therefore, when
using AIRBASS™, follow the Bridged Mono input and output wiring
output by as much as 3 dB. With Q values greater than .707, boost is
added to the sub-sonic filter. (see
10
figure 4)
5
0
Application
-5
dB
Installing AIRBASS™ involves removing the bottom plate of the amplifier,
adding the AIRBASS™ circuit board, and flipping a switch. The switch is
labeled on the amplifier's main circuit board. DO NOT set the AIRBASS™
switch to the "IN" position unless the AIRBASS™ module has been added.
DO NOT move the AIRBASS™ switch while the amplifier is "ON". Doing so
may damage your speakers. (Please refer to the AIRBASS™ owner's /
installation manual for more details.)
-10
-15
-20
-25
-30
Woofers in vented enclosures have
good power handling characteristics
above the tuning frequency, but
below the tuning frequency, power
handling drops off considerably.
10
Frequency (Hz)
50
100
200
FIG. 4 Variable “Q”
16
5
INSTALLATION STEP 5
Class A 5.0
LEVEL SETTING
The input levels are adjusted by means of the individual channel input level
controls located on the front of the amplifier. This is a unique dual-stage
circuit that adjusts both level and gain. This topology maintains better Signal
to Noise ratios even when using sources with minimal output.
In the ideal situation, all components in the audio system reach maximum
undistorted output at the same time. The reason is because an amplifier will
only make what comes into it bigger. So, if you send it a distorted signal from
the head unit, the amplifier is going to amplify distorted information. The
same thing holds true if an outboard processor or crossover begins to distort
before you have maximum output from the amplifier.
By setting all
components to reach clipping at the same time, you can maximize the output
of your system. For the REFERENCE Class A amplifiers, follow the following
steps for the quickest, easiest means of setting the levels.
1. Turn the amp’s input levels to minimum position (fully counter-
clockwise).
2. Begin with the input level switch in the 0.5 - 5.0 Volt position.
3. Set source unit volume to approximately 3/4 of full volume.
4. While playing dynamic source material, slowly increase the amplifier’s
input level until a near maximum undistorted level is heard in the
system.
If your preamplifier / source unit has an extremely high output level, be sure to
pay attention to the clipping indicators located on the top of the amplifier.
These indicators will notify you if you are clipping the PREAMPLIFIER stage of
the amplifier. If the amplifier's output is distorted and the clipping lights are
not blinking, you are most likely clipping the OUTPUTS of the amplifier, or
driving the speaker to distortion.
6
15
INSTALLATION STEP 4
INSTALLATION AND MOUNTING
Key to Callouts
1. AMPLIFIER LOCATION
The REFERENCE Class A amplifiers employ highly efficient circuitry and a
unique ChassisinkTM design to maintain lower operating temperatures.
Additional cooling may be required if the amplifier is located in a tightly
confined area or when driving especially low impedance loads at extremely
high levels.
1. Fault LED - Indicates a blown fuse.
2. Power LED - Indicates amplifier power on.
3. Input Overload Indicators - Indicates the signal input level or input gain
level is too high.
4. Input Level Selector Switch - Selectable input sensitivity range from 0.2-
2 Volts RMS, or from 0.5-5 Volts RMS.
5. Left Channel Balanced / Unbalanced Input Selector Switch - Select
"Balanced" to use the 6 pin Balanced signal Input. Select "Unbalanced" to
use the RCA signal inputs.
6. Right Channel Balanced / Unbalanced Input Selector Switch - Select
"Balanced" to use the 6 pin Balanced signal Input. Select "Unbalanced" to
use the RCA signal inputs.
When mounting the amplifier, it should be securely mounted to either a panel
in the vehicle or an amp board or rack that is securely mounted to the vehicle.
The mounting location should be either in the passenger compartment or in the
trunk of the vehicle, away from moisture, stray or moving objects, and major
electrical components. To provide adequate ventilation, mount the amplifier so
that there are at least two inches of freely circulating air above and to the sides
of it.
7. Main Fuse - Main power supply fuse. Replace only with the same value
fuse.
8. +12V - Connected to a fuse or circuit breaker, then to the battery's positive
post.
9. GND - Main ground connection. Bolt to a clean chassis ground in the
vehicle.
2. SWITCHES
Set the Coherent StereoTM/Mixed-Mono/Bridged Mono and Amplifier crossover
switches on the bottom of the amplifier to the appropriate positions before
bolting down the amplifier (see pages 13 - 16). Be sure to replace the hole
plugs.
10. REM - Remote turn-on input from the head unit. Accepts +12V.
11. Speaker Output Connections - Left and right channels.
12. Input Level - Independent Left and Right channel input level controls.
13. Balanced Signal Input Connector - 6-pin Balanced signal input
connector for use with the Soundstream BLT Balanced Line Transmitter.
14. Inputs - Right and left channel RCA (Unbalanced ) inputs; only right
channel input is used in "Mono" mode.
15. Coherent Stereo/Bridge/Mixed Mono switch - Select "Bridge" for
bridged mono operation (use right channel input). Select "Stereo" for
coherent stereo operation. Select "Mixed Mono" for simultaneous stereo /
bridged mono operation.
3. MOUNTING THE AMPLIFIER
a. Using the amplifier as a template, mark the mounting surface.
b. Remove the amplifier and drill the holes.
c. Mount the amplifier to the surface using the provided hardware.
4. WIRING
a. Run and connect the audio signal and remote turn-on cables to the
amplifier from the source unit.
b. Carefully run the positive cable from the amplifier to a fuse or circuit
breaker within 18” of the battery.
c. Connect the fuse or circuit breaker to the battery. Leave the circuit breaker
off or the fuse out until everything is bolted down.
NOTE: There may be a sizable spark when connecting the power and ground
lead to the amplifier for the first time. Please see the comment on the previous
d. Secure the ground cable to a solid chassis ground on the vehicle. It may
be necessary to sand paint down to raw metal for a good connection.
e. Double check each and every connection!
14
7
Class A
(Continued from page 12)
of blown power supply fuse, the “Fault” indicator on the top panel will light.
The fuse is accessible from the front panel of the amplifier. See the chart
below to determine the fuse value. Never replace the fuses with a higher
value than what is supplied. This may result in amplifier damage and will
REFERENCE Class A Amplifier Fuse Values
Amplifier
Amplifier Fuse
Battery Fuse /
Circuit Breaker
40 amp Maxi-Fuse
80 amp Maxi-Fuse
60 amp
Class A 5.0
100 amp
Class A 10.0
REMOTE TURN-ON
Connect the “Remote” to the turn-on lead from the source unit. When +12
volts is received, the amplifier will turn on.
SIGNAL CABLE
Use a high-quality cable that will be easy to install and has minimal signal loss
to guarantee optimum performance. Soundstream’s DL 1 and SL 1 are
ideal when using the Unbalanced RCA inputs. While using the Balanced DIN
input, use the cable supplied with the BLT.
SPEAKER CABLE
The REFERENCE Class A amps will accept up to 8 gauge speaker cable.
Use a high quality, flexible, multi-strand cable for best performance and
longevity. Soundstream Speaker120 & 160 (12 and 16 gauge) are ideal.
WIRING DIAGRAM
8
13
INSTALLATION STEP 3
Key to Callouts
WIRING
POWER AND GROUND
1. Fault LED - Indicates a blown fuse.
2. Power LED - Indicates amplifier power on.
3. LSE.Q Bypass Switch - Turns the LSE.Q on ("IN") or off ("OUT").
4. Input Overload Indicators - Indicates the signal input level or input gain level
is too high.
To ensure maximum output from your REFERENCE Class A amplifier, use
high quality, low-loss power and ground cables. The REFERENCE Class A
amplifiers will accept up to 4 gauge power and ground cables. Determine
5. Input Level Selector Switch - Selectable input sensitivity range from 0.2-2
Volts RMS, or from 0.5-5 Volts RMS.
up to 10’
up to 20’
6. Left Channel Balanced / Unbalanced Input Selector Switch - Select
"Balanced" to use the 6 pin Balanced signal Input. Select "Unbalanced" to use
the RCA signal inputs.
Soundstream Power40 or
Power80
Soundstream Power40 only
(4 ga.)
Class A 5.0
7. Right Channel Balanced / Unbalanced Input Selector Switch - Select
"Balanced" to use the 6 pin Balanced signal Input. Select "Unbalanced" to use
the RCA signal inputs.
Soundstream Power40 only
(4 ga.)
Soundstream Power40 only
(4 ga.)
Class A 10.0
8. Main Fuse - Main power supply fuse. Replace only with the same value fuse.
9. +12V - Connected to a fuse or circuit breaker, then to the battery's positive
post.
10. GND - Main ground connection. Bolt to a clean chassis ground in the vehicle.
11. REM - Remote turn-on input from the head unit. Accepts +12V.
12. Speaker Output Connections - Left and right channels.
13. LSE.Q - Frequency and Q adjustments.
14. Input Level - Independent Left and Right channel input level controls.
15. Balanced Signal Input Connector - 6-pin Balanced signal input connector for
use with the Soundstream BLT Balanced Line Transmitter.
15. Inputs - Right and left channel RCA (Unbalanced ) inputs; only right channel
input is used in "Mono" mode.
16. Coherent Stereo/Bridge/Mixed Mono switch - Select "Bridge" for bridged
mono operation (use right channel input). Select "Stereo" for coherent stereo
operation. Select "Mixed Mono" for simultaneous stereo / bridged mono
operation.
Read this, or sparks will fly!
The Soundstream REFERENCE Class A amplifiers have extensive internal
power supply capacitance, called the Ultra-Low ESR Capacitance Bank.
Multiple small input power capacitors act as an internal "stiffening capacitor".
Because of the large amount of internal capacitance, there may be a sizable
spark when connecting the power and ground lead to the amplifier for the first
time. In order to charge the capacitor bank without a spark, we suggest you
do the following:
1. Connect the +12 volt cable to the amplifier and to the battery.
2. Connect one end of the ground cable to the chassis of the vehicle.
3. We have supplied a 150 ohm, 2 watt resistor with the amplifier. One leg
of the resistor has been connected to the ground terminal of the amplifier.
4. To charge the capacitor bank, touch the loose end of the ground cable to
the open leg of the resistor for at least 45 seconds.
CIRCUIT BREAKERS/FUSES
EXTERNAL
Like all audio components, the REFERENCE Class A amplifiers must be fused
near the battery. A fuse or circuit breaker must be located within 18” of the
battery. This will prevent a fire in the event of a shorted cable. See the chart
below to determine the correct fuse value.
INTERNAL
The REFERENCE Class A amplifiers are fused with Maxi-fuses. In the event
(Continued on page 13)
12
9
INSTALLATION STEP 2
INSTALLATION STEP 1
COHERENT STEREO™ /
BALANCED / UNBALANCED INPUT
MIXED-MONO / BRIDGED MONO
The REFERENCE Class A amplifiers have the ability to accept either a
standard Unbalanced RCA signal inputs, or a Balanced "Pro Audio" inputs with
the use of the Soundstream BLT Balanced Line Transmitter or some other
balanced line audio source. Before installing your system, you should decide
The REFERENCE Class A amplifiers have the ability to operate in any one of
the following modes:
Coherent Stereo™ with identical left and right stereo channels for
maximum fidelity. Best choice for satellite speakers. Use this mode unless
Mixed-Mono is necessary.
UNBALANCED INPUT
BALANCED INPUT
ADVANTAGES 1. Most preamplifier / source 1. Improved Signal to Noise
units have "UNBAL" RCA
outputs. (Industry stan-
dard)
2. No Interface module is nec- 3. Immune to noise radiated in
essary the car audio environment.
Ratio. (S/N Ratio)
2. Excellent noise cancellation
characteristics.
Mixed-Mono in order to drive stereo and mono simultaneously; works well
for center channels. It can be used anytime you need a summed mono
channel. Somewhat sacrifices sonic accuracy as additional circuitry is
introduced to one channel. In Mixed-Mono, the left channel is inverted, see
diagram below or on the bottom of the amplifier.
The REFERENCE Class A amplifiers' signal inputs accept two ranges of input
signal levels: 0.2 - 2.0 Vrms, or 0.5 - 5.0 Vrms for both Balanced and
Unbalanced inputs. The input range switch position and level settings are
dependent upon the preamplifier / source unit output signal level. For the best
system Signal to Noise Ratio, we recommend that the input level controls be
set as far down as possible (rotated counter-clockwise), while maintaining an
acceptable level of output.
Bridged Mono for dedicated single channel operation; ideal for driving
subwoofers. It is also used when large amounts of power are necessary for
single speakers. In bridged mono, only the right channel input is active.
Using the "Unbalanced" RCA input
When using the Unbalanced RCA input, the RIGHT channel input signal
switch MUST be in the "UNBAL" position. Also, when first installing the
amplifier using this input configuration, we suggest that the left channel input
signal switch be in the "UNBAL" position as well. If you experience
alternator wine or other installation noise with both switches in the
"UNBAL" position, try moving the LEFT channel input signal switch to
the "BAL" position.
This should remove any system noise due to
installation.
In bridged mono, only the right channel input is active.
Using the "Balanced" RCA input
When using the Balanced 6-pin DIN input, both switches MUST be in the
"BAL" position. Also, we recommend that when using this input configuration,
the "INPUT LEVEL" switch be in the "0.5 - 5V" position, and the gains on the
NOTE:
If you intend to drive
a
REFERENCE Class A amplifier in Mono but
have stereo outputs from your crossover or
source unit, you can put the switch in
NOTE:
The pin
configuration shown
in the diagram is the
view looking into the
Balanced input jack
on the amplifier.
10
11
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