What tha DAC?

[Gordon Moore]

So here's the thing,
The DVD player I picked up states 192/24 DACs (Philips DVP642...nice little player by the way)....and that would be the output via analog stereo RCA cables....is that right?

The audio menu of the dvd player allows you to select 48 kHz and 96kHz....I would guess that's for the bitstream data? So by forcing the bitstream to 96kHz (PCM downconversion off), that allows my 96/24 receiver to do it's thing (Panasonic SAXR25 that digital amp vunder child : ).

Or am I confusing things?

(All I know is that PCM downconversion OFF
96KHz selected in player
Coax hookup
Front Speakers set Large
Subwoofer OFF

2-channel sounds pretty damn sweet.)

But ultimately my question is....am I understanding the 192/24 DACs of the player versus the 96/24 output of the receiver correctly?

[Kevin P]

Ya got it right Gord. The DACs in the player are capable of 192/24 (I assume the player is DVD-A capable, hence the high resolution). The bitstream output is switchable between 48 and 96 for DVD (video, not DVD-A) that have 96/24 bitstream tracks on them. The 48 mode is for receivers/processors that don't recognize a 96/24 bitstream.

Note that when you play a redbook CD you're only going to get a 44/16 bitstream out of the player, since that's all a CD has. Some concert/music DVDs have 96/24 tracks.

[Gordon Moore]

Thanks Kev :T

I assume the player is DVD-A capable, hence the high resolution

Only stereo outputs...but I guess DVD-A doesn't have to be 5.1, actually isn't 192/24 limited to stereo anyway?

Well the box doesn't specify anything specific about DVD-A but I guess it would work.

The bitstream output is switchable between 48 and 96 for DVD (video, not DVD-A)

Gotchya, so that switching to 96 while listening to CD wasn't making any difference then. interesting then because I was comparing the digital output of the Philips to the digital output of my old panasonic and there seemed to be a discernable difference.

Also keeping the path fully digital is the way to go with a digital amp as using the stereo out of the player caused the soundfield to simply collapse; meaning, I guess, that:

a. Panasonic digital amps do not do analogue very well (but that's okay by me as this is a foray into the digital realm anyway).
b. 192/24 doesn't mean much on a $89 DVD player

[Kevin P]

Yeah, the digital amps adds another variable to the whole analog vs. digital debate. With analog amps, the quality of the DAC was the deciding factor. If the transport has the better DAC, analog would sound better (pure analog pass through, not A-D/D-A like many receivers do). If the receiver or prepro has the better DAC, a digital connection sounds better.

Digital amps are, to simplify things, just a DAC that puts out a lot of power (relative to "normal" DACs). Unlike an analog amp which sounds best with an analog signal, digital amps prefer a digital signal, since analog signals have to be converted to digital. In a cheap implementation (low-cost Panasonic receiver), most of the cost cutting is probably on the ADC side (analog to digital), therefore you'll get the best sound quality with a digital signal. Fewer conversions = better sound.

[Bruce]

Gordon,

Don't know for sure, but many DAC/upsampler chipsets provide a variety of functions that will even take 44.1/16 and convert it to 48kHz (like audio cards in PCs) for input to a surround processor, which then processes it as 2-channel or surround depending on the processor's settings. It is also possible it could upconvert 44.1/16 to 96 for 2-channel PCM.

Also DVD-V sources, like those from Chesky, can be in a 96/24 format (about the max a digital coax or Toslink cable can accomodate) if the player can truly be set up to output that format.