Soundstream REF2.370, REF2.640, REF4.400, REF1.1000, REF4.760 User Manual

Don’t be a fool by throwing away this manual! Grab a couple brews, sit on your butt & READ THIS! You
will NOT be able to set this amplifier properly unless you thoroughly understand the sophisticated pre­amp section of the amplifier. You are now the owner of what may be the finest car audio amplifier ever
made. Please read this manual in its entirety. These brand new, long-awaited Reference amplifiers are
the finest amplifiers we have ever produced and they WILL change the way you hear and feel music…

REF1.500 REF2.370 REF4.400
REF1.1000 REF2.640 REF4.760

REF4.920

2

Table of Contents

Reference Lives 3
Features 4-5
Specifications 6
Installation 7
Controls and Terminals 8-10
Control Definitions 11-13
System Diagrams 14-17
Subwoofer Diagrams 18-19
Troubleshooting 20

3

Reference Lives!

Can you believe that it has been over a decade since the legendary Soundstream Reference amps graced the car
audio industry?! Maybe you bought this amplifier because the best amplifier you ever had was a Reference from back in
the day. Maybe you bought it for its legendary performance. Regardless of the reason, we know you’ll love your new SS
Ref & will appreciate its unparalleled quality.

When we first decided to reintroduce the coveted amplifiers, we just wanted something as fine as the originals.
They were finer than most amplifiers in the marketplace today. After failing to deliver for a couple of years, we decided
to hold back until we were 100% certain that there was nothing else we could do to make the amplifiers any better.
Many crappy clone amps popped up in Germany and Asia, but none were real Soundstream Reference amplifiers, and
they certainly did not come from us. We feel confident that we came up with everything you’d ever want. The preamp
controls are extensive. The circuitry is very advanced. Even the painstaking task of making sure every board trace is in
the perfect location yielded phenomenal results – damping factors from >1500 to >3000! Don’t fall for the foolish tale
that this doesn’t matter! The ability of an amplifier to accurately control the speaker is of critical importance! Duh!

Most amplifier manuals get thrown in the trash or never even make it out of the box. The new Ref amps are very
sophisticated and the silk screening on the front of the amplifier cannot begin to unfurl the powers of the new preamp
sections. It would not be wise to ditch this manual without thoroughly reading it over first. So grab a beer, a glass of
wine or a stupid latte and take a few minutes to chill out and absorb the intensity of the new SS Refs. Actually, if you are
reaching for a latte, you’re a fruitcake and do not deserve this amplifier. Grow a pair! Grab a 6-pack of your favorite mi­crobrew and read the freakin’ manual!!

*Note – while drinking some great beer is one of life’s greatest pleasures, please do not drink the whole 6-pack and attempt to work with electron­ics. Drinking fizzy, yellow light beer is for wussies and will probably make your amplifier spontaneously combust. Seriously, it happens. Sound­stream engineers are willing to install your amplifier for you if you send them a plane ticket for two and cover all expenses, including great beer.

4

Features

In the 80s, it became popular to use acronyms for amplifier features and technologies. In some cases, these acronyms
were nothing more than fancy words put together cleverly to form an acronym not worth its weight in poop! Sales people
memorized the silly acronyms but rarely knew what the feature encompassed. The features below are straight forward
facts about the amplifiers that make them yield audio nirvana.

General:

• Full Signal Path Low Noise/Distortion Circuitry Topology

• Optimal Component Layout for Minimal Distortion Induction & Signal Separation

• Full Differential Feedback Surrounding Power-Amp Stages directly from Speaker Terminals resulting in Uncolored

Sound Reproduction and Elimination of Ground Loops

• Differential Drives Divide Pre-Amp & Power-Amp Stages, Eliminating Ground Looping

• Triple Darlington Audio Output Stages

• Output Stage Bias Individually Sequenced, Optimizing Sound Quality

• Close Tolerance Signal Path Components - 1% Resistors & 5% Capacitors

• Stout 2 Oz. Copper Traces Effortlessly Transfer High Volume Internal Current

• Differential RCA Inputs Isolate 12V/Audio to Ground, Eliminating Ground Loops and Noise

• Sequenced Delays Eliminate Residual Power-Up/Power-Down Pops

• Final PCB Layout Designs are a culmination of examination and fine tuning of all circuit elements to work in harmony

as a whole

• Hawkins Boost Control - Proprietary Bass Equalization

• Continuously Variable Crossovers

• Tri-Mode Capable

5

PSU

• Pulse Width Modulated

• Large TO218 MOSFET Transistors

• High Volume, Low ESR Capacitance Banks Compensate Power Supply Ripple Currents

• Extra Low Current Drive Stage Increases Efficiency & Sound Clarity

• Individually Regulated Preamp/Crossover Power Supplies Ensure Signal Purity

• Separated Capacitor Charging/Discharging Current Paths Prevent Rail Switching Spikes & Ground Traces from En-

tering Signal Stages Resulting in Distortion

Mono-block Models:

• True Class G Circuitry and Regulated MOSFET Power Supply. This allows the Subwoofer Amplifiers to Yield the

Same POWER at 1-2 ohms, and Regardless of Operating DC Voltage. (You can use almost any amount of woofers,
and of any impedance, and wire it to the amplifier safely! See the options in the back of the manual…)

Common Specifications

Bass Boost 0-12dB 30Hz - 80Hz
Input Sensitivity 0.2V - 9V
Total Harmonic Distortion <0.02%
Supply Voltage 11-15VDC
Stereo Stability 2 Ohms
Bridged Stability 4 Ohms
Monoblock Stability 1 Ohm
Input Impedance 10k Ohms

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S P E C I F I C A T I O N S

REF2.370 REF2.640 REF4.400 REF4.760 REF4.920 REF1.500 REF1.1000
Channels 2 2 4 4 4 1 1
RMS Power @ 4Ω, 14.4V 2 x 110 2 x 190 4 x 70 4 x 115 4 x 145 - ­RMS Power @ 2Ω, 14.4V 2 x 185 2 x 320 4 x 100 4 x 155 4 x 215 500 1000
RMS Power @ 4Ω Bridged, 14.4V 1 x 370 1 x 640 2 x 200 2 x 380 2 x 460 - ­RMS Power @ 1Ω, 14.4V - - - - - 500 1000
Total Harmonic Distortion (4Ω power) 0.02% 0.02% 0.02% 0.02% 0.02% 0.02% 0.02%
Frequency Response 15-50kHz 15-50kHz 15-50kHz 15-50kHz 15-50kHz 15-200Hz 15-200Hz
Signal-to-Noise Ratio (4Ω power) 102dB 102dB 102dB 102dB 104dB 102dB 102dB
Damping Factor (100Hz, 4Ω) >3000 >1500 >2000 >3000 >2000 >2000 >2000

Dimensions: 2.25"h x 9.875"w
55mm x 250mm

13.58"

345mm

15.94"

405mm

16.06"

408mm

20.25"

514.5mm

22.81"

579.5mm

14.05"

357mm

18.17"

461.5mm

Ch. 1&2 HPF/Hawkins/Subsonic
(12dB Slope / 0-10dB Hawkins Boost)

15-240Hz or

275-4.1kHz

15-210Hz or

260-4kHz

15Hz-4kHz 15Hz-4kHz

15-240Hz or

240-4.1kHz

- -

Channels 1&2 LPF (12dB Slope)

50-210Hz or

820-4kHz

50-250Hz or

820-4.7kHz

- - - 50-200Hz 50-200Hz

Channels 3&4 HPF (12dB Slope) - - 15Hz-1kHz 15Hz-4kHz

15-220Hz or

255-4.1kHz

- -

Channels 3&4 LPF (12dB Slope) - - 55Hz-4.3kHz 50Hz-4kHz

50-250Hz or

800-3.8KHz

- -

Subsonic Filter Slope 12dB - - - - - 24dB 15-50Hz 24dB 15-50Hz
Phase Control Switch - - - - - 0 or 180

0

0 or 180

0

Remote Gain Control - - - - - Included Included
External Fuse Required 40 80 50 80 100 80 150