Specifications Click here to view product brochure Click here to view owner’s manual Click here to view photo gallery Overview The key to accurate audio reproduction is the ability to resolve detail. To that end, David Belles has designed his first class A amplifier in 30 years. Everyone knows that class A biased amplifiers represent the pinnacle of what is possible in amplifier performance. However, designing and building a class A amplifier is no easy task. The first amplifier that Dave Belles designed more than 30 years ago was an class A amplifier known as the Belles A. Since that time, Dave Belles has learned what it takes to produce a truly great class A designed amplifier. Class A design requires attention to tolerances, heat needs to be dissipated, power supplies need to be sufficient in order to produce an amplifier that does not compromise performance. The amplifier's power rating needed to be carefully selected in order to produce a unit that would drive most speakers at sound pressure levels that are satisfactory to most users. Class A design is the best, regardless of what anyone would try to tell you. Class B or AB designs use complimentary output transistors biased on the threshold of current conduction. The design uses one polarity of transistors to supply power to the loudspeaker load from the positive rail supply and another opposite polarity to supply power to the loudspeaker from the negative supply rail. Imagine that the amplified signal is in the form of a sine wave, where the positive supply rail transistors supplies the upper (or positive) portion of the wave, and the negative supply rail transistors supplies the lower (or negative) portion of the wave. Class B or AB design amplifier's transition from the positive to the negative portion of the sine wave is never perfect. This imperfect crossover from positive to negative creates a crossover notch, leading to crossover distortion. In B designs, another distortion is also created in the form of power supply modulation due to various signal power level demands. Switching type amplifiers have other deficiencies. Switching amplifiers take sample portions of the signal and reconstruct the wave at the amplifier's output using filters. This means that signal information is missing and the amplified signal is interpolated. The result is a lack of accuracy, detail and warmth. Class A designs do not suffer from any of the above deficiencies. A Substantial Unit From the quality of the circuit board components, to the heft of the chassis construction, the Belles MA-01 has been built to be a substantial audio component. The front panel is made of 1 inch (25.5 mm) thick anodized aluminum. The top and bottom covers are .25 inch (6.35 mm) anodized aluminum. A .125 inch (3.2 mm) anodized aluminum rear panel and massive anodized aluminum heat sinks complete the impressive chassis. The power supply consists of a 1000 volt-ampere toroidal power transformer with 234,000 microfarads of filtering capacitors. The output transistors consist of a bank of 20 mosfet power transistors. The Belles MB-01 is stable even with a 1.0 ohm load. All other components in the MB-01 amplifier are the finest: 1% metal film resistors, polypropylene capacitors, glass epoxy circuit board, oxygen free copper wire, oxygen free cast copper speaker binding post, gold plated oxygen free copper input connector. Also included is a on soft start power turn on circuit to eliminate power turn on surge transients and component failures.brochure__mb01_amp.htmlmanual__mono_amps.htmlGallery/Gallery.htmlshapeimage_1_link_0shapeimage_1_link_1shapeimage_1_link_2


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  85 watts into 8 ohms (Class A)

161 watts into 4 ohms (Class A)


0.2 to 100,000 Hz


Less than 0.01% rated power


Over 5000 into 8 ohms


80 amperes


1.17 for 75 watts


50,000 ohms unbalanced and 100,000 ohms CT balanced


>100 dB


21 voltage ratio or 26.44 dB


1 unbalanced RCA connector or 1 XLR balanced connector


17" W x 10.5" H x 13.5" D


75 lbs


120 VAC, 8A fuse (240 VAC 5.0A fuse optional)


5 years

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