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scope spdif source pops and crackles
Posted: Fri Aug 17, 2012 9:44 am
by ARCADIOS
I have connected my soundcraft M8 spdif out to scopes spdif in and nomatter If I record to Daw or VDAT the audio is always with many random digital clicks and pops.
Is there something I should know about the scope spdif input?
It is a pulsar2 card that has the input. i HAVE TRYIED all possible bit rates. All at 44.1, which my standard always, and also the only oprtion of M8.
ps. system with scope pro(14)+pulsar2(6)
Re: scope spdif source pops and crackles
Posted: Fri Aug 17, 2012 9:59 am
by the19thbear
Sounds like you havent set a ,master and a slave?
There can be only one master, all the rest in a digital signal chain are slaves.
Re: scope spdif source pops and crackles
Posted: Fri Aug 17, 2012 10:12 am
by jhulk
best to choose scope as master
as i find i get clicks and pops
you need to have one as master otherwise the digital clocks of both adat sources
will use there own clock and the clicks and pops are timing differences between the 2 devices adat digital clocks
Re: scope spdif source pops and crackles
Posted: Fri Aug 17, 2012 10:34 am
by ARCADIOS
scope is master.....mmmm
M8 does not have such an option. Justs sends the mix to the spdif output

Re: scope spdif source pops and crackles
Posted: Fri Aug 17, 2012 10:36 am
by jhulk
then the m8 needs to be master set scope to slave to the spdif
as obvouisly the spdif source clock is fixed as a master and cant be set to slave
Re: scope spdif source pops and crackles
Posted: Fri Aug 17, 2012 10:42 am
by ARCADIOS
I see that I can choose scope to be slave to M8 spdif. But I think it is not that safe, for example If I turn off the mixer scope system collapses!! board errors etc...
Do you think that it is a good idea to have scope slave to the mixers spdif for general scope use??
Re: scope spdif source pops and crackles
Posted: Fri Aug 17, 2012 10:56 am
by ARCADIOS
scope syncronized to M8 spdif and crackles are gone.ok.. I have the impression that the sound has improved as well, it is less sharp than before syncronizing.(I think)
Still I have to figure out if it is normal for using scope clocked to an spdif output. I thought that a dedicated clock would be more accurate.
by the way, how accurate are these chips? scope cards clock compared to my mixer spdif clock?
Re: scope spdif source pops and crackles
Posted: Fri Aug 17, 2012 11:13 am
by jhulk
they are set by a crystal
and spdif has been around for a long time now so its a stable clock
slaving scope is fine but always switch of scope before you switch of the mixer
as the scope system will lose its clock
unusual that there is no way of setting the spdif to slave some times theres a harware switch rather than software
it should be able to slave becuase when there are a lot of digital devices some times its best to have a master clock appogee bigben is a great master clock
Re: scope spdif source pops and crackles
Posted: Fri Aug 17, 2012 11:15 am
by garyb
if the device sending the digital signal only has a digital OUT, you MUST make that device master. in order for Scope to be master, the other device must have a digital IN.
it's just how things work.
Re: scope spdif source pops and crackles
Posted: Fri Aug 17, 2012 11:26 am
by ARCADIOS
soundcraft M series mixers do not have spdif in. This a miss but ok... I live. At least scope has both
According to audio quality, if there is dedicated clock(without audio signal) is better than having both passing through spdif(audio and clock)??
Re: scope spdif source pops and crackles
Posted: Fri Aug 17, 2012 11:42 am
by garyb
maybe.
you'll need bnc connectors on all devices. the main advantage to wordclock is to have a central master for all devices. it's much more important when you have a lot of digital devices to sync.
Re: scope spdif source pops and crackles
Posted: Sat Aug 18, 2012 12:45 pm
by ARCADIOS
the souncraft mixer M8 manual says that there are 2 methods of syncronizing.
1. Make soundcraft mixer master
2. Ensure the device receiving the digital signal is fitted with a sample rate convertor, which eliminates the
need for synchronisation.
The 1st ok, it is what I did so far.
The 2nd method.... "I do not understand ! ! .........

Re: scope spdif source pops and crackles
Posted: Sat Aug 18, 2012 12:58 pm
by garyb
#2, meaningless for 99% of the gear you might use.