User manual AUDIO ANALOGUE ROSSINI CD PLAYER REV2.0 REV 06-2008 INTRODUCTION

[. . . ] AUDIO FUTURA spa Rossini CD Player REV 2. 0 Issue Date: June 2008 AUDIO FUTURA spa Research & Development E-Mail (support): sblanda@audioanalogue. com podesta@audioanalogue. com saggini@audioanlogue. com elia@audioanalogue. com Rossini CD Player REV 2. 0 1/7 AUDIO FUTURA spa Introduction Even if the Rossini CD Player REV2. 0 has the same look of the previous revision it is completely different inside. With the REV2. 0 we have created a unit where the vacuum tube technologies and the best digital technologies could be perfectly mixed together. The circuits we have used come from a long research expecially for the original vacuum tube output stage that is the strong point of this CD Player. [. . . ] The SPDIF signal is then send to the DA conversion PCB. 2. Digital Analog Conversion Section The circuits performing the digital to analog conversion are placed on a board physically separated from the main board. That's to avoid any interference on the analog signals due to the return currents of the digital parts of the DAC and transceiver. On the board there are: the transceiver, the DAC and all their frameworks including their power supply voltage regulators and capacitors. The voltage for the "DAC board" is obtained by a dedicated secondary of the transformer and a dedicated voltage regulator. The regulated voltage is then filtered by a RC filter. Then that voltage is used to produce the voltages for the transceiver and DAC by two voltage regulators. The components on the "DAC board " are predominantly SMD reducing the length of traces carrying high frequency signals to avoid irradiation effects. From the "conversion board" the voltage DAC output is sent to the main board. Rossini CD Player REV 2. 0 4/7 AUDIO FUTURA spa 3. Output Stage The output stage is an original circuit designed by the Audio Analogue R&D office to emphisize the sound propertyes of the vacuum tube and to take vantage of the solid state technology. It is an inedited DC coupled low feedback three stage structure where the vacuum tube is the first one. The amount of feedback has been choosen not only on the base of measurements but on the base of listening tests too. What we have tried to do is a balance of the vacuum tube "coloring" and DAC "cleanliness". The output stage's gain is such that we have 1. 9Vrms output for a 0dBV track. 4. [. . . ] Perhaps this is expressly done to not show low frequency noise. Anyway the 50Hz noise component due to the AC Power supply and the 100Hz component due to the effect of the rectification of the AC power supply are the cause of the loudspeaker "hum". That's why they must be reduced in every audio devices. Note: All the measurements performed with a Audio Precision System Two Cascade. Misura dello spettro con apparecchio in stop. Rossini CD Player REV 2. 0 6/7 AUDIO FUTURA spa Misura dello spettro per 1Khz 0dbv Misura dello spettro per 1 KHz -10dbv. Rossini CD Player REV 2. 0 7/7 [. . . ]