Mono X 300

The Mono X 300 is a massively powerful amplifier, yet it is still housed inside just one aluminium die-cast chassis. Incredibly, it is able to drive over 300 Watts into real world speaker loads!

The most powerful amplifier created by Cyrus
Outputs over 300 Watts with outstanding control and dynamics
Zero Feedback circuit design eliminates unnecessary circuit paths for wide open imaging and pitch black background noise
Home automation control via RS232 and 12v Triggers for truly flexible installation options
Reference sound quality has been achieved through the last 7 years of product evolution and R&D research
Zero Feedback technology offers some very attractive sonic benefits. Two key benefits of this technology are:

1. The design allows the key stages in our amplifier to work independently without the hindrance of global feedback. In a traditional amplifier the corrective actions necessary in the output stage to drive a loudspeaker are fed through the entire amplifier, disturbing unnecessarily the input and voltage amplifier stages. To put this another way, it allows the first stage of the amplifier to operate without the unwelcome influence of the latter, separate voltage and current stages. Zero Feedback amplifiers are only possible when one understands how to prevent distortion in the first place. They require very advanced circuit topology and close tolerance components. Like our SE CD players, we want to deliver the best performance at source as this is the place where we will most improve the sound.

2. Cyrus Zero Feedback amplifiers are able to create an uncanny sonic blackness onto which we paint our musical image. They can achieve this because as the output level reduces to lower levels, where the ear becomes most sensitive to these effects, the distortion produced by the new Mono X models falls below measurable limits. The result is an exceptional musical performance.

Technical Information


Enclosure: Cyrus Inverted die-cast chassis
Material: Lightweight non-magnetic alloy


RCA phono or XLR balanced
12V Trigger

Bi-wire Loudspeakers (BFA terminals)
RCA Chain out

Power Supply:
Custom wound 305VA Toroidal transformer

MC-BUSTM System Bus

Continuous Power: 235W (into 8 Ohms), 365W (into 4 Ohms)
Burst Peak Power: >2000W
Distortion: <0.004%, (1kHz into 8 Ohms)
Frequency Response: -3 dB at 0.5Hz and 300kHz
Slew rate: 700V/S (filters bypassed)
Max output Current: 100 Amps peak to peak
Sensitivity (RCA input): 380mV (for 50W into 8 Ohms)
Sensitivity (RCA input): 890mV (for 225W into 8 Ohms)
Sensitivity (BAL input): 775mV (for 50W into 8 Ohms)
Sensitivity (BAL input): 1.78V (for 225W into 8 Ohms)
Input impedance: 47kΩ (RCA), 20kΩ (BAL)
Chain Output voltage: 660mV (for 660mV RCA or 1.3V BAL input)
S/N ratio: 116dBA
Dimensions (H x W x D): 73 x 215 x 360 (mm), 2.8 x 8.4 x14.1 (inches)
Weight: 6.4kg
Finish: Quartz or Brushed Black

Manuals and PDFs

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