Audio amplifiers Micromega

400 W, 10 - 50000 Hz, IEEE 802.11n, 13 kg, Silver AS-400 HIGHLIGHTS
Based on IA-400, our new high power integrated amplifier, AS-400 is the first integrated amplifier to benefit from AirStream technology.
AS-400 benefits from all functionalities from IA-400 with the same electrical design
and components quality. On top of this AS-400 is equipped with a completely new
AirStream module which brings the AirStream technology to a new level, providing a
music reproduction quality never reached before.
The new AirStream module is a completely new design with some unique features.
Based on an Apple Airport Express, the new AirStream module has been completely
revised. The four main sections, power supply, master clock, digital to analog
converter and analog output have been redesigned from scratch.
The power supply is separated in 3 sections using a multiple windings specific r-core
transformer. Three separate power supplies address each section: Main module,
Master clock, D/A analog section. All of these power supplies are different from each
other in order to supply the perfect DC power to each section. The main module
supply is a high power type with advanced ripple rejection techniques. The master
clock supply, made from a specific winding of the transformer, is an extremely low
noise type featuring a total noise of less that 7nV/√Hz. The D/A analog section supply
regulator features low noise high voltage tracking regulators.
The 25 MHz master clock oscillator is now build specifically for us by the leader of
low jitter oscillator's manufacturer. It is a Micromega part bearing the HD AUDIO logo
laser engraved on. This master clock features jitter <-100dB at 10Hz deviation from
the main band. This is exceptional and guarantees a perfect digital audio stream.
This oscillator and its specific ultra low noise power supply are now on a separate
circuit board soldered to the shield of the airport module. This avoids any distance
between the clock and the IC receiving this signal.
The D/A converter is completely new and do not use the airport D/A converter
anymore. The new D/A chip is a CS4351 Cirrus Logic part which features 2V rms
output level. This D/A chip is followed by discrete pure classA Jfet buffers developed
specifically for this purpose. These buffers feature a 1MΩ input impedance which
represent a very light load for the output section of the D/A converter IC. These
buffers produce less than -100dB distortion from 20Hz – 20kHz and there low output
impedance is a perfect match for the AS-400 specific Air input. 1.5uF Wima
polypropylene capacitors are used to isolate the biased output of the D/A converter
IC from the Jfet buffers inputs. A second order Bessel filter, aligned at -3dB at
130kHz, removes all spectral rays present in the audio signal. Dynamic range is
exceptional, transparency and realism are key words to describe the sonic quality of
this new AirStream unit. Once again the D/A converter section is on a separate pcb
soldered to the shield of the airport module to avoid any induced jitter when carrying
high speed signals. A specially designed 0.5mm pitch flexible pcb links the airport
module to the D/A converter module.
A small back lighted AirStream logo present on the front lens indicates the status of
the AirStream module.