Exceptional Sounding MX1255 Twelve Channel Amplifier

 MX1255 12 channel amplifier...

  • High Current twelve channel amplifier rated at 55 watts RMS per channel (100 watts peak).

  • NEW FEATURE! Bridge two channels together for a 180 watt output. Perfect for subwoofers!

  • Electronic Link feature connects stereo inputs channel two through six to channel one.

  • Side-mounted hush-tone fan for internal cooling.

  • Individual and automatic channel resetting protection for low impedance, overheating, overloading, overvoltage and undervoltage.

  • Two rack spaces (3-1/2") with optional rack mount.

  • Individual level gain controls for all channels.

Nice pool sound system...



The perfect choice when exceptional sound quality is a specific requirement


The Knoll MX1255 is our fourth generation high current multichannel amplifier. It's a class A/B amplifier that produces 55 watts per channel at 8 ohms and 70 watts per channel at 4 ohms. Our legendary amplifier reliability (25+ years) is built into each and every MX1255.

The class A/B amplifier design circuitry was chosen simply because of its obvious sound quality superiority over other high efficiency designs such as class D or class H.

Knoll multi-channel amplifiers sell worldwide because of their legendary reliability and unparalleled sound quality. Features such as gold RCA input jacks, detachable speaker wire connectors capable of using 12 gauge wire, individual channel rear mounted gain controls, and more set this amp apart from all others in its class. An optional 19" rack mount adaptor kit is available.


MX1255 Specifications:

Inputs Gold RCA jacks with adjustable gain
Input impedance 50k ohms
Outputs detachable screw terminals (12g)
Output power 55 watts RMS per channel (8 ohms)
Peak output power 100 watts per channel (8 ohms)
Bridged output power 180 watts per channel (8 ohms only)
Ideal impedance 4 - 8 ohms
Frequency response 10 Hz - 40 kHz +/- 1dB (1w)
S/N ratio over 105 dB A weighted (50 watts)
THD distortion less than 0.1% 20 Hz to 20 kHz
IMD distortion less than 0.01% 60 Hz 7 kHz 4:1 (SMPTE)
Dimensions 17" x 3.5" x 11.5" (432 x 89 x 292mm)
Fan Noise quiet 28 dBA
Power (maximum) 750 watts at 117 VAC or 230VAC
Weight 21 lbs (9.5 kg)


iBoost Stereo signal booster for weak signal sources and when 2 or more MX850/MX1255/MX6120 are linked together the iBoost provides a strong buffered stereo signal. 10/20 dB boost.

MR100 Stereo preamp with wall mounted decorator style keypad. Adjustable bass, treble, balance and volume. Power on/off via keypad. Easy to install.

RACKMA Rack mount ears for a standard 19" rack is available. Occupies two rack spaces and we strongly recommend a blank space above and below the MX1255 for maximum power output.


An eight channel version is available, Knoll model MX855.


MX1255 user manual...  MX855 cut-sheet...