Hi John,
Was wondering if my PM got through to you , or are you still clearing the back log?
Regarding the BDAC, can both XLR and RCA outputs be used simultaneously?
The questions been asked many times and the answers always the same - it depends upon the system how the loading of each output effects each other. Nobody so far has reported any significant degradation...
i'm also curious about the differences between BDAC and MDAC, performance-wise. The BDAC's ess 9023 is capable of 112 DNR theoretically, and comparing this to the 133 DNR of the 9018, how will the 9023 perform better? Of course DNR and on-paper specs aren't the be all end all, but technically the 9023's a lower spec chip, ain't it?
Beyond a certain level measurements tell us very little about sound quality - its all too easy to start getting hung up on measurement results.
LP and Studio Tape's sound far better then CD IMHO - yet with "convectional measurements" and our interpretation of these measurements they should sounds far worst.
I'll be modifying a couple of MDAC for PFMers - with these modifications there is a significant leap in audio quality - but nothing I can measure directly on the audio output.
I'm expecting (but yet confirmed) that the BDAC will sound better then MDAC due to the more advanced circuit designs around the DAC. My only real concern about the ESS9023 is its horrid "Fast" Digital Filter - although we will pre-process the input Data hopefully to lessen the sonic impact... How suspenseful this will be remains to be seen.
If you could put in the same improvements for the BDAC, into a new 9018-based DAC, would the 9018 DAC be better? I'm guessing that would be reserved for the statement lakewest stuff?
I'll never use the ESS9018 again as an integrated DAC solution in our designs its SO FULL OF BUGS. We pull our hair out, its REALLY REALLY Buggy, some issues are more serous then others... ESS should really have re-spun the silicon to resolve the bugs.
You also mentioned that the BDAC's clock phase noise performance is better than the MDAC. Forgive me if i'm mistaken, i thought the higher quality clocks tend to be more expensive and am wondering how you achieved that since the BDAC's a much cheaper product. That's quite impressive indeed!
Luckily for audio we are only concerned about short-term phase noise / close in carrier noise - thus we do not require complex and expansive temperature control etc.
Maybe due to old age, I missed the boat with MDAC - I already developed a simple circuit topology that dramatically improves LF noise performance many years ago, but I simply forgot about it while designing the CD/CDQ/MDAC.
To meet the BDAC's price point and yet also meet the performance level, I've had to go fully discrete in almost every circuit block - this requires much greater design time and knowledge, but I've got peace here in Europe to design, not having to deal with what can only be described as daily "Crap" while based in China - not to mention being permanently hungry and ill due to the bad food quality...
John