DACs and A/D converters What are these?

Quote:
Hifialan,


When you are listening to DVD-A or SACD through the analog direct input - you are using the DACS in your DVD/CD player.


The information on DVDs and CDs is digital - "1"s and "0"s. At some point, these have to be changed to analog signals to

be amplified to drive your speakers.


Your DVD player has DACs in it - so that it can output the analog signal that you are inputting to your receiver.


In all likelihood, your DVD/CD player also has a digital output, so that you can use it not as a DVD "player" but as

as DVD "transport". In this case, you would feed the digital

data from the DVD to your receiver using the digital output on the DVD player, thus bypassing the DACs in the player.


The receiver, would use its DACs to convert the signal to analog, for amplification for the speakers.


Some receivers have the capability to do digital "effects" - they can process the digital data to make it sound like you're

in a small club, or a big arena. This processing has to be done on the digital signal. If you feed an analog signal

to such a processor, it will use ADCs - analog to digital converters - to turn the signal back into digital. If you

have a digital source like a DVD player - and you use this capability, you don't want to use analog inputs. The

receiver is going to take the analog input and convert it back to digital - the receiver's ADCs will undo what the

player's DAC did, and then after processing the receiver will process the signal with it's own DACs.


If you are not using digital signal processing in the receiver, then the question is - which one has the better

DACs - the player or the receiver. If the player has better DACs - use the analog inputs.


However, if you have a medium quality DVD player, and a high-end receiver, then you should use a digital connection;

so that you will be using the DACs in the high-end receiver.


Greg

Quote:
hifialan,


It depends. Although the receiver has 192/24 dacs, it probably also has 44/16 or 44/20 dacs. If it sees a 44/16

signal from the CD player - it may just process this with the 44/16 dacs.


Or it may upsample to 192 so that the effect of the low-pass filter is mitigated. Or this may be selectable as an option.


It depends on the design of the receiver.


Dr. Gregory Greenman

Physicist

Greg,


It would be highly unusual to have multiple DACs to handle the various sampling rates. It would be one DAC capable of syncing to N number of bit depths and sampling rates, with 32, 44.1, 48 and multiples of these base frequencies to the limit of 192K. It would also support sampling depths of from 16 to 24 bits, usually with word lengths of 16,20,22 and 24 bits.


There are implementations of multiple DACs, but that's to reach the appropriate number of channels, or to go into a differential configuration, not specifically to handle various input sampling rates and depths.


Perhaps I misread the post?


Regards,

hifialan,


There are a couple of options here.


One, is an 6 or 8 channel DAC vs. multiple stereo DACs, with the stereo DACs having a marginal improvement over the 6 or 8 channel DAC.


Then there's running differential, or dual differential, which increases the number of DACs in use per channel, which again gives a marginal improvement in performance.


Audibility is another issue altogether, as you are always listening to more than just the DAC.


Regards,