Rather than use a Class A design, which is sonically brilliant but generates vast amounts of heat, or a Class AB design, which is efficient but sonically limited, we developed our own Class XD amplifier design which the 851W takes advantage of. This has the sonic purity of Class A and the efficiency of Class AB for the best of both worlds. For more information on our unique patented Class XD technology watch the video at the bottom of the page or click here for a full description.
When designing a stereo system, listeners are often encouraged to think about system matching, where components are handpicked to provide the best overall sound quality. People often assume this is due to the different audio characteristics, but frequently it is due to impedance (the relationship between voltage and current input/output) matching components. Products perform at their optimum when their input and output impedances match. This isn’t always possible though so we decided to develop our unique Terrapin impedance buffering module. This enables the 851W to be paired with a huge variety of audio sources and pre-amplifiers of varying impedance without risking any sacrifice in musicality or overall audio performance.
POWER AND CONTROL
To build the 851W to be the best toroidal transformers were essential. But rather than use one for everything we designated one for the sound amplification itself, and another for the input circuitry. This means the signal is unaffected by audio output volume, so always sounds fantastic. The primary toroidal transformer provides unrestricted power to the dual mono amplification blocks. It’s a true audiophile transformer that will operate without distortion and with no buzz, interference or hum. The second smaller toroidal transformer takes care of pre-amplification processes. View the videos below for an insight on why we use toroidal transformers.
The 851W can be used in stereo, bi-amped or bridged mono configurations. In bridged mono mode into 8 Ohms the 851W is a 500W monoblock amplifier. Into 4 Ohms, this figure increases to an incredible 800W. It can be paired with our 851E pre-amp, any of our digital pre-amps such as the 851N or CXN, or any other analogue pre-amps, and thanks to our Terrapin buffering module it will always sound perfectly matched.
CAP 5 PROTECTION
Our proprietary CAP 5 protection system protects the 851W, plus any connected equipment and speakers, ensuring ultimate reliability and peace of mind. For more information on this unique development have a watch of the video below.
Power output – stereo/mono – 200W per channel into 8 Ohms 350W per channel into 4 Ohms
Power output – bridged mono – 500W 8 Ohms 800W 4 Ohms
THD (unweighted) – < 0.001% 1 kHz < 0.005% 20 Hz - 20 kHz
Frequency response – 5Hz – 80kHz
S/N ratio (ref 1W / 8 Ohn) – >90dB (unweighted)
Sensitivity – stereo or mono – 1.5V rms unbalanced 1.5 + 1.5V rms balanced
Sensitivity – bridged mono – 0.775V rms unbalanced 0.775V + 0.775V rms balanced
Input impedances – Balanced input 38 kOhm Unbalanced input 68 kOhm
Power amp damping factor – > 110 at 1 kHz
Max. power consumption – 2400W
Standby power consumption – Standby <0.5W
Dimensions (HxWxD) – 148 x 430 x 365mm (5.8 x 16.9 x 14.4”)
Weight – 19.1kg (42.2lbs)