Alcune info in piu'
Here are some thoughts on the SR8012 based on the following YouTube video and a webpage. In places the SR2012 is compared to the SR7012 because that seems a logical comparison, and helps to answer the question, "Is the SR8012 worth the added cost over the SR7012." Of course if you watch the video and read the webpage you can draw your own conclusions.
The YouTube video on the SR8012 very clearly shows the slides, in English, of a presentation on the SR8012. This presentation gives very good insight into the design features of the SR8012. The worthwhile content starts about 31 minutes in.
https://www.youtube.com/watch?v=Zne1C7dewR0
Translating this site into English provides additional insight:
http://m.marantz.jp/jp/Products/Page...oductId=SR8012
Digital Board:
The digital board, the top board seen in back of the unit, provides the current standard features of the Marantz/Denon line. It's an eight-layer board and no doubt very advanced. It offers the chip that support eARC with future firmware. This board is likely the most advanced in the unit, and of course runs the firmware (software) for the unit. This board will change significantly in future units that support HDMI 2.1. Not much else to see here since details aren't publically available.
DAC Board:
The two eight channel AKM DAC's are on this board along with the opamps that provide output filtering and an interface the rest of the unit. Compared to the SR7012 there appear to be more/larger capacitors tied to the opamps, which like provide power filtering. Just visually, the board appears to be an upgrade to the DAC board in the SR7012.
HDAM Board:
Much more space is provided for the HDAM circuits and each channel has it's own space vs. the SR7012. In the SR7012 each two channels are very close together. The SR8012 HDAM board should provide better cooling. Whether this allows a move to the 12V power rails of the AV7704 and AV8802 isn't clear. The HDAM board in the SR8012 appears to be a significant upgrade over the HDAM board in the SR7012 at least in physical layout. Better HDAM performance will provide a better input to the internal amplifiers. If external amplifiers are used for some channels, an improvement in the HDAM's should provide better pre-out performance to drive these amplifiers.
Volume Control:
The SR8012 adopts the eight-channel JRC volume control that is used now in at least many of the higher end Denon/Marantz AVP/AVR products such as the SR7012. The JRC audio switching chips are also used. This is a big improvement over the AV8802, as Marantz notes in the video, and most components of a few years ago, that used a combination switching/eight channel volume control from Renasys. This JRC volume control provide performance in line with the rest of the unit and is a clear improvement over the Renasys unit.
Switch Mode Power Supply:
The webpage indicates that the SMPS, which provides power to the digital circuits, has been upgraded to run at three times the switching frequency of previous units. Which previous units is unclear. Just for example: the switching frequency may have been increased from 50kHz to 150kHz. The higher frequency, and its multiples, will be much to filter out, from both the output of the power supply, and from returning to the 120V AC line. This change should provide an improved S/N ratio.
Cooling:
The heat sinks in the SR8012, while not huge, have a cross section that should allow good heat distribution. The cooling fans below the heat sinks appear to be well sized and placed to provide coverage of the entire heat sink. In many AVR's the fans appear to be an after thought, and won't provide good airflow over the entire heat sink. AVR's closely monitor various temperatures and current flows, and control fan speeds and rail voltages, to provide optimum operation and protect the unit. Ultimately better cooling means higher output. Attention, including added cost, was paid to cooling in the SR8012.
Separate Amplifier Boards:
These boards provide more space for components and improve cooling, it's not just the power transistors that get hot. The added space allows for added circuitry, and the opportunity to improve performance. The amplifiers in the SR7012 are on two circuit boards. The SR8012 seems a significant upgrade over the SR7012 in this area.
Power Supply:
The SR8012 adds a toroidal transformer and the filtering capacitors are quite large. The weight of the SR8012 is increased over the SR7012. Likely the transformer is a major reason for the weight increase. Since toroidal transformers are more efficient that EI units, the increase in transformer capacity should be more than is indicated by weight alone. This webpage explores linear power supply design in detail, including a section on sizing capacitors:
http://sound.whsites.net/power-supplies.htm
Sembrerebbe che l'8012 sia ben studiato ed un deciso passo avanti rispetto al 7012 (ci mancherebbe)
La cosa interessante e che sulla carta dovrebbe avere anche una miglior parte pre nonostante monti lo stesso dac.
