MONO MOSFET POWER AMPLIFIERS

MA4-M9-M14
MA8
M1020-M15
M series Mosfet power amplifiers are the result of a careful circuit research to keep in a solid state amplifier that sweetness and warmth and, at the same time, speed and definition typical of the FT hybrid amplifiers, so appreciated by the critics, musicians and trained audiophiles. To achieve absolute channel separation and for a better stage image, these amplifiers are mono. Furthermore each amplifier can be located near the speaker it has to drive and a great heat sink area, compared with the external dimensions, permits high bias current or class A operation.
Mosfets have good musical qualities and thanks to their intrinsic thermal stability and second breakdown immunity no protection or current limiting is necessary in the signal path. In the proper amount and fed by an oversized power supply they make these amplifiers able to deliver the necessary current to drive easily any kind of speakers, even the most difficult like the electrostatic ones.
A high damping factor helps to obtain a good control of the woofer, and, consequently, a tight, fast bass.
The driver circuit is formed by two fully complementary cascode, class A transistor stages, each with its own local feedback, performing high linearity and large bandwidth.
The power stage is biased with high current and works in class A at normal listening level. The MA4, MA8 ,M15, deliver all their power in PURE CLASS A and must not be confused with so many, so-called, class A in the market, which aren’t. Class A cancels crossover notch distortion, brings about improvements in both bandwidth and phase integrity, increasing so, remarkably, the quality and definition of the sound.
Components have been carefully selected for their sound performance and reliability.
The good looking chassis of completely anodized and brushed aluminium assures, with two generous heat sinks, reliability and steady performances even after many hours of continuous playing.
To sum up, they are strong and fast ( rise time < 2ms ) amplifiers, with solid bass and accurate, detailed sound. Musical instruments are perfectly separated and located, timbres and ambience are natural, transients are reproduced with the realistic impact of a live performance without compression or harshness.
These models are identical in circuit topology, differing only in power supply, bias and number of devices.
HIGH BIAS MONO MOSFET POWER AMPLIFIERS
SPECIFICATIONS M9 M14 M1020
Nominal power 90 W 8W, 150 W 4W 140 W 8W, 220 W 4W 200 W 8W, 350 W 4W
Classe A 100W CLASSE A
Bandwidth 2 Hz – 200 Khz 2 Hz – 200 Khz 2 Hz – 200 Khz
Input sensitivity and impedance 1V / 100 KW 1V / 100 KW 1V / 100 KW
Signal to noise ratio > 85 dB  > 85 dB > 85 dB
Harmonic distortion < 0.1 % < 0.1 % < 0.1 %
Damping factor >80 >130 >250
Output stage 4 Mosfet 6 Mosfet 12 Mosfet
Power supply trasf.tor 250 W, 30.000 mF trasf.tor. 380 W, 30.000 mF trasf.tor. 380 W, 60.000 mF
Dimensions cm 23 (w) x 9.5 (h) x 33 (d) 23 (w) x 9.5 (h) x 33 (d) 32 (w) x 9.5 (h) x 33 (d)
Weight 6.5 Kg 10 Kg 12 Kg
PURE CLASSE A MONO MOSFET POWER AMPLIFIERS
SPECIFICATIONS M A4 M A8 M15
Nominal power 40 W 8W, 65 W 4W 90 W 8W, 150 W 4W 200 W 8W, 350 W 4W
Classe A 100W CLASSE A 
Bandwidth 2 Hz – 200 Khz 2 Hz – 200 Khz 2 Hz – 200 Khz
Input sensitivity and impedance 1V / 100 KW 1V / 100 KW 1V / 100 KW
Signal to noise ratio > 85 dB  > 85 dB  > 85 dB 
Harmonic distortion < 0.1 % < 0.1 % < 0.1 %
Damping factor >80 >130 >250
Output stage 4 Mosfet 6 Mosfet 12 Mosfet
Power supply trasf.tor 230 W, 30.000 mF trasf.tor. 300 W, 88.000 mF trasf.tor. 380 W, 60.000 mF
Dimensions cm 23 (w) x 9.5 (h) x 33 (d) 23 (w) x 19 (h) x 33 (d) 32 (w) x 19 (h) x 33 (d)
Weight 6.5 Kg 6.5 Kg 10 Kg