[Tech2]

I tried a forum search, really I did.

But I still have a question about DAC's.

My current understanding is that a DAC, when connected to a transport such as a DVD/CD player (using digital coax or optical output) converts the digital signal to an analog input to your amp.

My question is this:

If you use a DVD player as a source, does this mean that you are getting a pure digital output directly from the transport (vs an analog signal from the RCA connections)? In other words, are you bypassing the DVD player's internal DAC by using the digital output on the player? If you use the digital output on the DVD player for your home theater, is your receiver (in my case) converting the digital signal with an internal DAC to power your speakers?

Thanks.

 

[jjcha]

Quote:

Originally Posted by Tech2 I tried a forum search, really I did. But I still have a question about DAC's.

Totally understandable. I totally drowned in the concept for a long time when I started out (a year ago... and I still don't get a lot).

Quote:

Originally Posted by Tech2 My current understanding is that a DAC, when connected to a transport such as a DVD/CD player (using digital coax or optical output) converts the digital signal to an analog input to your amp.

That is correct.

Quote:

Originally Posted by Tech2 If you use a DVD player as a source, does this mean that you are getting a pure digital output directly from the transport (vs an analog signal from the RCA connections)?

For the most part, yes. I think there are some DVD players that add processing into the digital signal (or just do a really horrible job sending it out) because jefemeister did a comparison of digital outs from dvd players, and surprisingly, they all weren't what is called "bit-perfect".

http://www6.head-fi.org/forums/showthread.php?t=92688

Quote:

Originally Posted by Tech2 In other words, are you bypassing the DVD player's internal DAC by using the digital output on the player? If you use the digital output on the DVD player for your home theater, is your receiver (in my case) converting the digital signal with an internal DAC to power your speakers?

Your understanding is exactly correct!

You're gonna hate me for this, since you understand this stuff pretty well, um do a search for the term "jitter".

Best regards,

-Jason

 

[Tech2]

Thanks Jason.

 

[jefemeister]

Quote:

Originally Posted by jjcha ... jefemeister did a comparison of digital outs from dvd players, and surprisingly, they all weren't what is called "bit-perfect"...

That particular Toshiba player I measured had some serious issues. It has nothing to do with DVD players in general. I imagine most are bit-perfect, perhaps some resample which isn't really bad. Even so, it is usually selectable via a on-screen menu.

But yes, using the DVD player's digital out will completely bypass the DVD player's internal DAC. It is possible that the digital out can carry other information too (surround channels, etc) but this would also be selectable.

 

[Tech2]

Quote:

Originally Posted by jefemeister That particular Toshiba player I measured had some serious issues. It has nothing to do with DVD players in general. I imagine most are bit-perfect, perhaps some resample which isn't really bad. Even so, it is usually selectable via a on-screen menu. But yes, using the DVD player's digital out will completely bypass the DVD player's internal DAC. It is possible that the digital out can carry other information too (surround channels, etc) but this would also be selectable.

Thanks Jeff. And kudos for all of your work on the DAC comparison. I have to admit, though, right now most of the info in that thread is going right over my head since I have very little knowledge on the subject.