22-Jul-2016, 18:16
Guillaume
According to the graphic on the 1000 Pro literature, The DAC is followed by the Magic Wire, which appears to then have a current to voltage conversion (not in line) before the Class A and Class D amplifiers and the control algorithm (which I understand manages the A/D interaction). The graphic in the Phantom literature is the same.
According to Mathieu when he was in Oxford, there is definitely no new DAC or any plan to change it. He explained to me that the DAC is the Texas Instruments PCM179X series, high voltage variant, so I suspect it is the PCM 1792A which outputs 4.5V. Apparently this high output is a requirement of the ADH architecture.
This is what Devialet's text says in the Phantom literature:
"Just ahead of the ADH® amplification stage, another major technological advance from Devialet is used: the “Magic Wire”. The aim of the patented “Magic Wire” typology is to implement the DAC (Digital to Analog Converter) at the core of the class A amplifier, in order to reduce the parasitic, music-impeding phenomena - such as noise and distortion - to an absolute minimum.
In practice, the output current of the highest performance DAC on the market (Texas Instrument PCM179X series) is directly converted into high-voltage without any processing in between: no operational amplifier, no current mirror. Instead, the very elaborate leak-less path of the “Magic Wire” carries the original current of the DAC to an ultra-high linearity resistor (0.01% precision), which operates the current/high-voltage conversion before entering into the class A.
The magic comes from the fact that the guiding elements within the “Magic Wire” do not process the music, whilst providing high-voltage output. Besides, these guiding elements work at a stable power rate, hence constant temperature, which reduces thermal distortion to a non-measurable quantity. In a simplified view, the “Magic Wire” can be considered as the dream of every audiophile: a straight wire with gain."
On the firmware side, the OdA runs on Platform 5 which uses ADH3.3 and PSU 4.4. This is the same Platform as the Expert series. The 1000 Pro runs on Platform 6 which uses AHD4.0 and PSU6.3. This platform will also apply to future Pro models. I don't think this means that 3.3 and 4.0, and 4.4 and 6.3, are necessarily any different, but examination of the hex files suggests that it would take weeks to compare them unless there is any software around that does it automatically.
According to the graphic on the 1000 Pro literature, The DAC is followed by the Magic Wire, which appears to then have a current to voltage conversion (not in line) before the Class A and Class D amplifiers and the control algorithm (which I understand manages the A/D interaction). The graphic in the Phantom literature is the same.
According to Mathieu when he was in Oxford, there is definitely no new DAC or any plan to change it. He explained to me that the DAC is the Texas Instruments PCM179X series, high voltage variant, so I suspect it is the PCM 1792A which outputs 4.5V. Apparently this high output is a requirement of the ADH architecture.
This is what Devialet's text says in the Phantom literature:
"Just ahead of the ADH® amplification stage, another major technological advance from Devialet is used: the “Magic Wire”. The aim of the patented “Magic Wire” typology is to implement the DAC (Digital to Analog Converter) at the core of the class A amplifier, in order to reduce the parasitic, music-impeding phenomena - such as noise and distortion - to an absolute minimum.
In practice, the output current of the highest performance DAC on the market (Texas Instrument PCM179X series) is directly converted into high-voltage without any processing in between: no operational amplifier, no current mirror. Instead, the very elaborate leak-less path of the “Magic Wire” carries the original current of the DAC to an ultra-high linearity resistor (0.01% precision), which operates the current/high-voltage conversion before entering into the class A.
The magic comes from the fact that the guiding elements within the “Magic Wire” do not process the music, whilst providing high-voltage output. Besides, these guiding elements work at a stable power rate, hence constant temperature, which reduces thermal distortion to a non-measurable quantity. In a simplified view, the “Magic Wire” can be considered as the dream of every audiophile: a straight wire with gain."
On the firmware side, the OdA runs on Platform 5 which uses ADH3.3 and PSU 4.4. This is the same Platform as the Expert series. The 1000 Pro runs on Platform 6 which uses AHD4.0 and PSU6.3. This platform will also apply to future Pro models. I don't think this means that 3.3 and 4.0, and 4.4 and 6.3, are necessarily any different, but examination of the hex files suggests that it would take weeks to compare them unless there is any software around that does it automatically.
