Soundstream Reference 4.400 Four Channel Amplifier

Product Details
Manufacturer: Soundstream
Distributor: Pro Plus Audio Distribution
TEL: 0207 993 8889 (for nearest dealer or dealers’ enquiries)
US Website: soundstream
Typical Selling price: £449.00
What It Is
The intention was for the return of an amplifier legendary in its own lunchtime. This is a four channel amp of the Soundstream Reference series, yet the makers state that certain components have improved down the years since they were in production a decade ago and that they are even better nowadays. Below the specifications, I publish their bragging rights about how they design their amplifiers, from their USA website. Rated at 4×70 watts at four Ohms.

In A Nutshell
A pretty and retro-looking amplifier that has some serious electronic constructional chops as a high sound quality product. The GENUINE 102dB signal to noise ratio means huge fidelity and the enormous damping factor really keeps the amplifier’s grip tight on the tunes. I found it clean, sweet, just powerful enough and as long as not over driven, possessed of great clarity and headroom. So much so, that you will find it used as a reference amp (As in no need to listen to anything but the speakers you are testing, like it was, ‘A straight wire with gain’) in a goodly few Talk Audio reviews done recently, prior to this date.
The SCORES
Overall 8.8
Sound Quality 10
Power Output 8
Features 8
Build Quality 10
Value For Money 8
This IS an expensive amplifier and excellence costs, so the Talk Audio Awards are first, Recommended on the points scored overall;

But ALSO and just because it sounds so damn GOOD, we give it the specific Talk Audio Reference award Just like it says on the tin. (er heatsink)


Specifications
Channels 4
RMS Power @ 4Ω, 14.4V 4 x 70
RMS Power @ 2Ω, 14.4V 4 x 100
RMS Power @ 4Ω Bridged, 14.4V 2 x 200
Total Harmonic Distortion (4Ω power) 0.02%
Frequency Response 15-50kHz
Signal-to-Noise Ratio (4Ω power) 102dB
Damping Factor (100Hz, 4Ω) < 2000
Dimensions: 55mm x 250mm x 408mm
Ch. 1 & 2 HPF/Hawkins/Subsonic
(12dB Slope/0-10dB Hawkins Boost) 15Hz-4kHz
Channels 3&4 HPF (12dB Slope) 15Hz-1kHz
Channels 3&4 LPF (12dB Slope) 55Hz-4.3kHz
External Fuse Required 80
General:
Sequenced delays eliminate residual power-up/power-down pops
Differential RCA inputs isolate 12V/audio to ground, eliminating ground loops and noise
Full signal path low noise/distortion circuitry topology
Optimal component layout for minimal distortion induction & signal separation
Triple Darlington audio output stages
Differential drives divide pre-amp & power-amp stages, eliminating ground looping
Full differential feedback surrounding power-amp stages directly from speaker terminals resulting in uncoloured sound reproduction and elimination of ground loops
Output stage bias individually sequenced, optimising sound quality
Stout 2 Oz. copper traces effortlessly transfer high volume internal current
Close tolerance signal path components – 1% resistors & 5% capacitors
Hawkins boost control – proprietary bass equalization
Continuously variable crossovers
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 entering signal stages resulting in distortion

Editor Review : Soundstream Ref 4.400 four channel high sound quality amplifier
Rated at four by seventy watts, this amp will happily run at two ohms all day. I didn’t, using it upon the reviews for a slew of kit, one of which was the Kenwood FLAC headunit seen here: here and if you ain’t clicked away here’s a quote: ‘I fired it up, playing it through a rather lovely Soundstream Ref 4.400 amplifier of reference quality like it says – into some high quality speakers with tiny bullet tweeters and sweet midband capability as well as a bit of bass and I was just delighted.’
I also used it in speaker tests like the Clarion SRE 122S components and described the amp I used: ‘I had them on a really posh amplifier to see how well they worked.’
For the simple fact is that the amp was costly but gorgeous sounding and a less posh Soundstream amplifier is used by our own Rodders of the Modders in his lovely retro Porker. Seen here: here
I used the amp so long as a reference, I simply don’t have a slew of musical try-thises. It actually became something I didn’t fret over and accepted as a reference piece and as such. I can keep it brief for a change!
Damn Fine Amp for audiophiles who really care not just about the notes and the order they are played in, but also that they arrive at your ears in the same order as they were made, too!