Reference Two Channel Power Amplifier 857
Our most powerful reference two channel amplifier has been designed and built to deliver the best possible Hi-Res audio performance from any high-quality passive loudspeaker system. Its low-feedback construction provides ultra-low distortion, ensuring an unparalleled level of clarity and transparency across the audible range.
Bridgeable to over 1.5Kw, the Meridian 857 features a totally new design for a Meridian power amplifier, borne out of extensive research, experience and a thorough understanding of psychoacoustic principles.
Key Features
Effortless power delivery of 500W per channel into four ohms and bridgeable to >1.5kW mono into 4Ω.
1-100kHz frequency response -/+ 2dB – Perfect for high resolution audio.
Fan assisted cooling operating at elevated temperatures enabling silent operation in room and rack installations.
Low feedback construction provides ultra-low distortion, ensuring an unparalleled level of clarity and transparency across the audible range.
With its extensive Research and Development programme Meridian has pioneered the development of a host of innovative audio technologies many of which feature in today’s Meridian products.

The open-loop characteristics of an amplifier are crucial to its sound quality. The power amplifier design is intrinsically linear and uses error correction in the output stage to provide low open-loop output impedance. This allows the power amplifier to achieve impeccable measured performance and a high damping factor while only applying modest amounts of negative feedback.
The use of shunt feedback to eliminate common mode distortion is well known. Meridian’s proprietary ‘Superbal’ circuitry brings this advantage to the balanced input, while also converting unbalanced signals to balanced as they enter the amplifier.
The rack-mount variant of our most powerful
reference two channel amplifier.
AUDIO INPUTS
Two XLR balanced inputs
Two RCA unbalanced inputs
AUDIO OUTPUTS
250W RMS into 8 Ohms per channel both channels driven
500W RMS into 4 Ohms per channel both channels driven
Bridgeable to >1KW RMS into 8 Ohms • Bridgeable to >1.5KW RMS into 4 Ohms
4 WBT terminals per side allow bi-wiring
CONTROL SIGNALS
Trigger input [3.5mm 5-30 VDC]
COOLING
High level of passive cooling for silent in-room running
Six variable speed fans maintain amp functionality if hostile thermal conditions encountered in rack
DISPLAY
Backlit touch sensitive logo changes colour to indicate amplifier’s status
‘Standby’ [BLUE], ‘Normal Operation’ [GREEN]’, ‘Fans Active’ [AMBER], ‘Overload’ [RED]
DIMENSIONS
HEIGHT:
175mm [6.9in] without feet
195mm [7.7in] with feet
WIDTH:
480mm [18.9in]
DEPTH:
Standalone 445mm [17.6in]
Rack-mount 425mm [16.8in]
WEIGHT:
Standalone 32kg [70.5lbs]
Rack-mount 35kg [77.1lbs]
CONSTRUCTION
Black finish in aluminium and glass
Dedicated Rack-mount variant (4U high)
Custom Meridian Select colours also available
POWER
Advanced linear power supply: 100V ac 50/60 Hz | 110-120V ac 50/60Hz | 220-240V ac 50/60Hz