New clock on satelite receiver

[FaZ72]

Hello,

Since i sometimes wach tv connecting my Humax CI-5100 salelite receiver to my external dac, i'm wondering if it is possible/makes sens to install a new clock in the dac in order to reduce jitter.

Thanks

[analog_sa]

Makes sense? For the mpeg stream? I sincerely doubt.

[FaZ72]

Well, even cd's burned from mp3's still sound beter when played on a good transport

[Elso Kwak]

Originally posted by FaZ72
Hello,

Since i sometimes wach tv connecting my Humax CI-5100 salelite receiver to my external dac, i'm wondering if it is possible/makes sens to install a new clock in the dac in order to reduce jitter.

Thanks

Hi, I have played with the idea. But my receiver is still in warranty and full of tiny SMD parts.......
I saw a 27 MHz canned crystal oscillator but I am not sure this is the one to tackle....
Also need a servicemanual....
MPEG sounds kind of funny.......
I don't believe the commercial talk that it is equal to CD quality......

[alfsch]

Hi,
i had this also in mind, to see the quality, thats possible at all, i downloaded some secs of the digital stream and looked at the spectrum...about 70db dynamics, thats like a cassette tape! so no need for a ultra low jitter clock, i think.
alf

[FaZ72]

To my personal experience, jitter maily affects imaging and ambience. Has this any relation with dinamic range?

[alfsch]

Dynamic range is just a indicator for the resolution, so if its like an old cheap cassette deck, no way to make it hi-end. Jitter by itself at first limits low level resolution, so i see no sense to reduce jitter here, you only get a noise floor with improved noise...and i forgot to say: improving jitter on a dig-receiver = improving pll, because the sat downstream has its own timing and the receiver has to be synchronized to it; so the xo clock is only the reference for the dsp and its pll. Improving this is not easy, because the rf loc has a pll and the mpeg output is sync to another pll, on the data speed. here a fft of a musik transmission, see the max dynamic 130db, but in audio is only (20db max,-96db noise floor) about 76db in the 32k-fft, maybe about 50db effectiv. not much,eh ?

[Bricolo]

Originally posted by Elso Kwak


Hi, I have played with the idea. But my receiver is still in warranty and full of tiny SMD parts.......
I saw a 27 MHz canned crystal oscillator but I am not sure this is the one to tackle....
Also need a servicemanual....
MPEG sounds kind of funny.......
I don't believe the commercial talk that it is equal to CD quality......

Most of the time, having digital audio is enough for them to write "CD quality" on the box...

[arniel]

Originally posted by Bricolo



Most of the time, having digital audio is enough for them to write "CD quality" on the box...

With the state of CD mastering today, my kids Fisher Price cassette deck is "CD quality".

As for MPEG audio streams, this is probably going to be MPEG layer 2 (not MP3), which doesn't have the same complexity of filtering. On UK DVB broadcasts, I can quite clearly hear the compression artefacts in a 192k bitstream. By comparison, mp3 is very good at that rate. Listen for any form of audience noise e.g. clapping to really detect the nasty fluttering sounds instead of crisp claps. I've even heard FM broadcasts that have obviously been relayed from a compressed bitstream

The BBC really has gone downhill in recent years, and I'm not just talking about the programming...

[FaZ72]

But the point in not attaining audiophile quality from an mpeg2 stream. I beleive very few people on this forum (if any) think about that
The point is, since i am still listening to this signal, to improve it.

Connecting the receiver to a high-end dac realy makes a big improvement. The question is if, even improving the clock of the source changes the sound also