The fascinating FM 1811

Evolution or Breakthrough? Both. The winning combination results in the ultimate Resolution Series Amplifier
Evolution or Breakthrough? Both. The winning combination results in the ultimate Resolution Series Amplifier



The fascinating new FM 1811 is the culmination of FM ACOUSTICS efforts in 45 years of dedicated R&D.


Not many words are needed to explain the FM 1811:

it really is the ultimate solution to highest accuracy in music reproduction.



The FM 1811 leads to a new standard of excellence in the  Resolution Series ® design.



New solutions and dozens of refinements are combined with new features


  • New symmetrical input stage provides the highest symmetry and best balancing ever

  • New ultra high linearity driver stages

  • Newly developed dual chassis eliminates mechanical resonances and reduces mechanical noise to inaudible levels

  • Includes FM ACOUSTICS unique resonance isolators

  • The most dramatic output stages ever created provide absolute linearity even at highest currents

  • Two new astoundingly quiet fans using special control circuitry that follows the dynamic envelope of the amps' performance and thermal demands. The resulting silence contributes to the FM 1811's dramatic dynamic rendering.

  • Ultra high efficiency cooling with thermal envelope optimization

  • Many custom-made components of singular standard and quality

  • Phenomenal new hand-assembled, layered and frozen transformer uses unique specially treated ultra high-efficiency steel.

  • Capacitors of absolutely ultimate quality made to proprietary specifications
Not a power station; the highest resolution power supply.
Not a power station; the highest resolution power supply.
The heart of the matter...
The heart of the matter...

Ultra-high quality


Of course, all characteristics that have made FM ACOUSTICS amplifier world renown - like singular discrete circuits, individually tuned and hand calibrated FM ACOUSTICS enhanced class A stages, use of hand-and-listening selected semiconductors etc. - are incorporated.
The Resolution Series ® 1811 delivers unheard of realism and a "be there" experience for which neither words nor technical terms exist. The FM 1811 drives any speaker to a performance level that until now could not be reached - and imagined.

The FM 1811 requires an ultra-high quality, ultra low-impedance mains supply to deliver its promise. A dedicated supply that can provide a minimum of 125A peak / 25A cont. at 120V   (or 60A peak / 12.5A cont. at 230V) is required.



Some Specifications


Minimum Power Output:
Per channel, both channels operating with continuous music or continuously repetitive toneburst:
1000 Wpeak into 8 Ohms
1800 Wpeak into 4 Ohms
3200 Wpeak into 2 Ohms

500 WRMS into 8 Ohms
900 WRMS into 4 Ohms
1600 WRMS  into 2 Ohms
(Just for comparisons' sake: the impulse power is more than 4500W per channel...).

Max. Output Voltage:

180 V pp.

Max. Output Current:
Absolutely unlimited peak current (over 550 A!). More than 80 A continuous per channel allows the FM 1811 to drive any known load with optimal fidelity.
No fuses, absolutely no form of current, voltage or any other kind of limiting are employed.

Distortion:  better than 0,005% THD

Gain:    30,1dB

Risetime at Full Power -3dB:               3 us   

Hum and Noise:    (20Hz-20kHz).
Below full power typically: -115 dB
Min. unweighted: > than -100 dB

Input: Proprietary, electronically balanced, discrete enhanced class A circuitry, floating ground, non-inverting or inverting mode.
Optimal performance with either balanced or unbalanced (single-ended) sources.
Unbalanced sources are automatically balanced right at the inputs of the FM 1811.

Interference Rejection:
105 dB typically, guaranteed better than 95 dB 

Maximum Input Level:
+20 dBm (7,75 VRMS)

Load Impedance:
No minimum impedance. Designed for below 1 Ohm to above 10’000 Ohm systems. Can drive any speaker impedance - dynamic, electrostatic, ribbon, planar etc. - without any compression, limiting or any other negative effects on the audio signal.

Despite this, the amplifier is fully protected against short circuits and all other adverse conditions via a unique on-board system that continuously surveys all important parameters.


Unique protection systems proprietary to
FM ACOUSTICS protect against adverse conditions such as short circuit, open circuit, HF Oscillation, RF interference, +DC and -DC offset, multi-fan activity, temperature, blocked or dirty fan filters, damage to the protection system itself, etc.

Chassis Resonance Damping:
New dual chassis design effectively isolates sensitive electronic and mechanical components from potential negative influences such as induced resonances. Mechanical resonance damping on panels is employed. The chassis including cover, transformer mounting, transformer leaves, side panels, capacitor mounting etc. use purpose-designed anti-resonance technology.

Average Life Expectancy:
At 25 o C ambient temperature, medium power, 10h/day, 365 days/year:                                                                         38 years.

Power Consumption:
At idle:                   200 WRMS
At 30% power:       1400 WRMS
At full power:         3600 WRMS
With dynamic signals:

            10000 Wpeak repetitive

Mains Supply Requirement:
No mains voltage drop when supplying:
25A continuous, 100Ap at 110V - 120V
12.5A continuous, 50 Ap at 220V - 240V

Burn-in Time at Factory:
Minimum 100 hours (500 thermal cycles)   

Vibration Test at Factory:
Minimum 60 minutes (50’000 vibration cycles)

Output Connectors (soldered to FORCELINES):
FORCEPLUG 200, ultra low-loss high-performance connectors.
Continuous current handling = 200A, 1200Ap


For the FM 1811 FORCELINES 3 are required to guarantee ultimate performance.

Spare Parts Availability:
Guaranteed available for a minimum of 10 years. Ex stock availability of 99% of all individual parts.

Weight:   Only 45 kg net,

50 kg packed

430 mm wide
260 mm high
550 mm deep


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8132 Egg b. Zurich



Phone:  + 41-44-7257777

Fax:     + 41-44-7257790


Last updated : 23.04.2024