MAESTRO: music machines
The Maestro series represents the highest expression of Audio Analogue technology applied to music reproduction.. Audio Analogue has optimized the whole signal paths, aiming mainly at an extreme components choice: very tight tolerance resistors, highest attention for interfacing, MIL grade components,
oversized supplies.
The idea behind the designers’ work talks about a detailed sound that, without wasting any detail, provide for a high emotional involvement: the recreated virtual space, the texture control at low frequencies, the smooth presence in the mid range and the airy purity of the high frequencies, all make for the sound of the Maestro Series to be the closest approach to the desirable possible sound reproduction.
The style of the Maestro is that of a product by the highest formal synthesis, yet revealing the exceptional quality of its contents: the front panel’s shape with the central protrusion is an imagery fo the sound that these equipment deliver to the environment around them.
The insightful usability of the equipment has been one of the primary targets Audio Analogue’s designers have pointed to: a metal like alunimum, that apadt itself by discreetly reflecting the colours from the surrounds, the immediate ease of the controls, the legibility and soberness of the silkscreens, the use of rustproof steel pushbuttons, the cabinet and pushbutton’s rounded edges
come from an exhaustive study on the equipment’s use and their functionality and safety.
Displays with calibrated lighting for a perfect legibility without an invasive presence; the remote control, small but heavy, gives user an unusual and pleasant consistency for an object which represents a sanctuary in soberness and technical correctness. Maestro: hymn to joy of listening!

CIRCUIT'S CONFIGURATION
The basic structure of the amplifier Maestro MONOBLOCK is the same used in the precision balanced amplifier used in the laboratories.
It is made of three different amplifiers. The first two must amplify in tension the balanced signal and the third one must supply the necessary current amplification to drive the speakers. This kind of structure has two important benefits: the first one is a high immunity to the disturbs, while the second one is the possibility to improve each amplification stage. The separation between the gain in tension and of the gain in current permits to realize class A tension amplifiers made with low power components, so to obtain a frequency response up to about 500kHz. Such frequency extention gives the possibility to mantain the phase errors to a very low level. The power section has been designed to obtain a high gain in current and not in tension. Thanks to this solution, it is possible to keep the frequency response at full power around at
200kHz. Also the bass frequency extention has been realised with care applying an off-set recover circuit able to go down to 3Hz.
Due to its two stages configuration, the amplifier Maestro Monoblock does not have a global feedback between inputs and outputs.

POWER STAGE
The Maestro Monoblock’s nominal output power is of impedance. This power goes up to 800W@2ohms. The protections starts to work at around 1000W with a load of 1ohm(if your house system can support it!) To obtain these kind of power levels the supply section has been overdimensioned. In fact, have been used two toroidal transformers for a total of 1406W. Each power branch is rectified from a diode’s bridge, with 50A components and the filter section contains 8 electrolytic 15000F capacitors for a total of 120000 F. Furthermore, also the supply of the low power section has been realized one bridge for each branch and filtrated with two 15000F capacitors. To maintain a low output impedance has been realised 10 pairs of bipolar transistors whom low distortion level are guaranteed by the producer. Their polarization current permits to get a class A working up to about 10W.
The current pass trough some copper bars. Each earth converges to a sole junction (star configuration) realised with a copper plate half a millimetre thick that has also a shielding function. Obviously, such big quantity of different parts is used to supply only one channel of your stereo system!

PROTECTIONS
An amplifier able to supply more than 30 ampere must be well protected. The amplifier Maestro Monoblock has a section exclusively
dedicated to this function. At the moment of the switching on, the filter capacitors are loaded trough two power resistors to limit the power comsumption. Once the supply voltage has passed the critical phase, the resistors are excluded by two 40A relè. These relay are able to stop the supply of the power amplifier and have been used to replace the fuses. The only existing fuse on the Maestro Mono is used to protect the control board and hasn’t any effect to the audio signal. There are also others protections that are used to control the presence of DC power on the speakers, the AC power voltage drop and the current absorbtion surplus.