Storm D02A word clock

[Konig]

Quote:

Originally Posted by akwok Liudas definitely knows his stuff. Hmm. Wonder what other choices there are for a nice minimal-jitter, word clock I/O sound card for <$300. I'd love to get the Squeezebox modified, but nobody does word clock I/O mods (not too sure if it's even possible). The Transporter is too expensive if I'm only going to be using it as transport.

"In principle, the device is OK, but it is a
run-of-the-mill massed produced standard product, it is made of cheap
components since the company is looking seriously at their profit margin and
there are many converters in that device, so they don't have the luxury of
going into high quality solutions.

You know, the Tektronix tds 2000 series oscilloscope (around $2000) with
which they measure Jitter on their webpage, we had borrowed one of those
while testing our DAC's clock performance and we received no results -- 0
visible Jitter -- nothing whatsoever. In order to measure the small amount
of Jitter of the DAC 2004's clock oscillator, we would need to use a much
higher level of machinery which measures up to 5 GHz reliably and which
costs around $50,000, and this equipment doesn't even exist here in
Lithuania.

We once met up with an engineer named Matthias from RME, this was at the
Frankfurt pro music and light international trade show. We asked him why he
doesn't use the ever so slightly more expensive but much better Burr-Brown
operational amplifiers in his circuitry, and he replied that there is no
difference in measurements and no difference audibly, and we found no reason
to discuss with him any longer. "

 

[akwok]

Kind of stuck up..

 

[thomaspf]

Quote:

Originally Posted by Konig Quote: Originally Posted by akwok I was thinking of getting the Hammerfall HDSP 9632 sound card with the word clock module for moderately cheap (~$250-$300). Any thoughts? I had wanted to get that but liudas from lessloss say it isnt worth the price due to its relatively high jitter they've found.

I am not sure I follow this logic. I thought the whole idea of feeding a word or superclock back from the DAC to the source is to become independent of the source jitter. The wordclock is used to frequency lock the source to the DAC. The DAC needs to be able to deal with slight delays but it reads the incoming signal purely by its internal clock which is independent of the source.

The RME word clock input achieves exactly that and is therefore a good solution if you have a DAC with word clock output.

Am I missing something?

Cheers

Thomas

 

[alex_cs]

the lynx22 has word clock doesnt it?

 

[thomaspf]

The lynx has word clock output and input.

What you want for low jitter digital conversion is a w/c input to connect to a DAC that provides a matching output.

You will probably not want to make the clock inside your computer the master clock for your playback chain.

Universal audio,Meitner, DCS, Apogee are examples of companies that make DACs with w/c outputs.

Cheers

Thomas

 

[Tachikoma]

Urm... is it possible to do the reverse then? As in adding a word clock input to a DAC.

 

[Thaddy]

Yes it's possible, as the D02A has both input and output. I'll add an image in a sec...

edit:

 

[thomaspf]

You can do that but it will likely result in much higher jitter for the D/A conversion. You can't get any lower than having a crystal directly drive the converter.

The w/c inputs on DACs are meant to be used for scenarios where you need a house clock that drives multiple boxes which in many cases includes the recording A/D converters. For the highest recording quality you need the master clock in the A/D box since you can never get rid of that jitter otherwise.

For a playback system in your house you do not want a clock external to your DAC. A BigBen or anything else will give you worse results compared to a good local crystal oscillator directly in the DAC.

Cheers

Thomas

 

[studeb]

Quote:

Originally Posted by Tachikoma Urm... is it possible to do the reverse then? As in adding a word clock input to a DAC.

yes
it is part of the I2S standard.
Transmits word clock, serial data and serial clock
you can pick them up of the player's chips.