[PlanetCCRMA] Problems with a quite complicated audio system

Mark Knecht Mark Knecht <markknecht@gmail.com>
Tue Jun 21 15:00:01 2005

On 6/19/05, michele.spinolo@tin.it <michele.spinolo@tin.it> wrote:
> Hi Mark,
> >Are you sure the Zsys is not corrupting the sound? What sample rate is
> >the SACD player playing at? 48K? If so is there any chance that the
> >Zsys isn't really resampling since it thinks both are at 48k?
> >
> the SACD is outputting at 24bit/88.2Khz, so the Z-sys should realle resample
> the incoming signal.
> >How about telling the Zsys te sync on the SACD player? Or does this
> >not work becuase you lose clocks when the SACD player isn't rolling?
> it is not possible because the z-sys cannot tae the clock signal from s/pdif
> inputs, and it must downsample to 48 or 44.1Khz to make output avaible on
> ADAT (it is not a RME product, so no Double speed mode)

OK, this is still bothering me. I suspect that while the Zsys can do
ASRC I'm suspecting that it may be what's causing you trouble.

You may or may not be able to set this up, but if I were you and was
trying to get to the bottom of this I would do this:

1) Hook the SACD outputs into the spdif input of the HDSP 9652.
2) Set the HDSP 9652 to sync to the spdif input.
3) Verify from hdspconf that it is indeed synced.
4) Set the ADI-8 Pro so sync with the HDSP 9652. Either sync over ADAT
or use the WC output from the HDSP 9652.
5) Listen and see how it works.

If the sound is good then I suspect that the Zsys, while indeed
possibly doing ASRC, is the root cause of the problem.

Good luck,

> >> >   It sounds as if you have 3 spdif OUTPUTs from the SACD player
> >> >giving you 6 audio channels. However I don't see a spdif input so I
> do
> >> >not understand how the player is getting sync'ed to your ADI-8 Pro.
> >> >
> >>
> >> ADI-8 Pro is synched to the Z-sys unit, which rebuilds the clock signal:
> >> so everything should be synched.
> >> To be more clear the Z-Sys unit is used just as a s/pdif to ADAT converter
> >> plus ASRC.
> >
> >And I'm hoping that the 'A' in ASRC isn't what's hurting you. If the
> >SACD player's clock was slightly slower than the ADI-Pro's clock then
> >it seems to me that your buffers may run dry and possibly the Zsys
> >could be trying to fill in data or something. Anyway, I guess I don't
> >have much to add other than getting everything truly synch'ed would be
> >good.
> >
> I hope this is not the problem: the ASRC function in Z-sys is built to allow
> synching of unsynched s/pdif inputs (i.e. you can have 3 totally different
> s/pdif sample rate inputs), so it should work.
> I e-mailed to z-sys in order to have some clarifications.
> >>
> >> >   I would think that in this case, if you want to play a CD from this
> >> >unit and have the sound be correct you need to tell the HDSP 9652 to
> >> >sync to the Zsys and you need to tell the Zsys to sync to the SACD
> >> >player. The SACD player will be the master and everything should be
> in
> >> >sync.
> >>
> >> The Z-Sys does not have an internal clock, but it must be provided on
> one
> >> of its ADAT inputs: this could be done synching ADI-8 Pro to HDSP9652
> by
> >> wordclock, for example, and using ADI-8 Pro ADAT output to sync the Z-sys
> >> unit.
> >
> >I guess is cannot take a clock from a spdif input?
> you are right!
> Thanks!
> Michele