44kHz 24 bit?


#1

I have the DSD and DMP and when I first started playing CDs the DAC display would sometimes show 44kHz 24 bit. Now when I play a 24 bit CD it only ever shows 44kHz 16 bit. How did I get it to show 24 bit before, or did I imagine that?

I’m not looking for an explanation of resolution and bit depth, per se. laugh

Thanks!


#2

What are you using to feed the DAC CDs?


#3

May not apply to your situation, but if you have any other digital devices attached that are outputting clock, they would cause the display to show their rates the instant the current source stops. And just checking - you have in fact 24 bit CDs? I have them from my prior recorder, but 24 bit CDs are not the norm.


#4

The DS displays what it gets, if it says 16 bits then the bottom 8 bits are all zeros. CDs are all 16 bits (or they aren’t a CD, but some CD cases say things like “24 bit mastering…” or even more confusing things that lead some to think they should get 24 bits.)

If the DS is displaying 24 bits when playing a CD then something upstream is doing some processing, perhaps some volume control or the Windows Mixer is doing some limiting, etc.


#5

Firstly, I corrected my post to say DSD and DMP. It’s a simple setup with DMP -> DSD -> preamp -> amp, using the supplied HDMI cable.

With this setup under what circumstances would the DSD display 44kHz 24 bit?

You’re right, I’m playing some 24 bit mastered CDs that show 16 bit on the display. It’s just that I’ve seen the display show 24 bit but can’t remember what I played.

It does show 44kHz 24 bit when no CD is inserted.


#6

If you played almost anything but a standard CD you’d probably see 24 bits. (DTS CD, DVD, DVD-A, Blu-ray, DAD, many DVDs burned on a computer, …) Also, (and I’m just speculating since I don’t have a DMP), I don’t know if the DMP does HDCD (or if it’s an option) but if it does you might see 24 bits (or even 20 bits) on a disk with the HDCD flags (some CDs have the flags even tho HDCD isn’t anywhere on the disc cover.)

[Edit:] One other wild guess, have you verified that you have the Pure Audio option set? (http://www.psaudio.com/forum/directstream-memory-player/pure-audio-setting/#p66570)


#7

Yes, I have the Pure Audio option set? Does it affect bit depth?


#8

I don’t have a DMP, but I have an Oppo similar to the transport of the DMP and it’s hard to keep the video related speaker setup, etc. from messing with the audio. I don’t know if the Pure Audio setting affects processing of the bits or not in the DMP.


#9
Ted Smith said I don't have a DMP, but I have an Oppo similar to the transport of the DMP and it's hard to keep the video related speaker setup, etc. from messing with the audio. I don't know if the Pure Audio setting affects processing of the bits or not in the DMP.
Thanks Ted! We're working on getting a DMP to you. New load of products coming this month.

HDCD is not supported by default because it would mean we couldn’t be bit perfect and we chose to forego the small improvement possible to make sure we’re bit perfect.

The Pure Audio setting turns off the Oppo video engine which does make a difference in sound quality to these ears.


#10

Paul, I thought you removed all the video stuff? What is it shutting off, are the video chips(?) still on the main Oppo board?


#11

We didn’t physically remove all the video stuff, we simply disabled and shut down the noisy video engine. The Pure Audio mode was specially programmed to do exactly that - and that’s why it should be enabled.


#12

Thanks Paul, I used to use it on my Oppo 83se whenever I used it to just play music. But since I got the PWT and the Lindemann I haven’t used the Oppo for anything but getting total time of CDs, when I need to play something that will fit, before I have to leave.