What's the best DAC digital interface possible?

[Blizzard]

Correct... I have never used an external clock that made the converter sound better. If it does, either the unit is broken or the manufacturer didn't know how to implement it correctly. Internal clocks have always sounded better.

Now... here's the caveat. If you are in a studio and are using "multiple" converters, you DO need a master or central clock to get them all to play nice. Here's where the external clock does make the individual converters sound better.

Or you can use Ravenna/Dante and the grand master clocking system

 

[Blizzard]

So how do you manage an 8TB library with the loimited interface? is it that you have to resort to playlists?

How many albums do you have on 8tb? How would you deal with them in vinyl, cd or R2R? What would hold more tracks in a smaller footprint and be the easiest to manage?

 

[Blizzard]

If USB is so bad then I wonder why the latest and greatest DAC's recently brought to the market seem to focus on using the USB interface if one wants to play the highest quality/bit rate music files from said DAC? If one chooses to use an SPDIF input on these units they usually only getting 24/192 as an option for playback.

All the talk about noisy USB makes me wonder what people are using as a music server in these situations. Even if the DAC doesn't use galvanic isolation its still possible to achieve a clean, low noise connection between the two devices over USB as long as the music server is a low powered/lightweight unit.

I'm using a small Alix server running Voyage Linux that I built and it only requires about 13v DC @.23amps to run which is equal to about 3 watts (going by memory on exact figures but you get the idea). In this configuration the grunge level and noise traveling down the USB pipe is almost non existent. I can stream up to DSD128 over DOP via USB to my Meitner DAC with this little server with zero issues and the Meitner has no isolation on the USB Input from what I'm told. There is no noise to these ears.

Actually all the latest cutting edge DAC's either have Ethernet renderers built in or I2S inputs. Speaking of the Meitner? Did you compare the ST fibre with the USB yet? The Xmos chip with no Galvanic isolation is a result of Ed not caring much about USB because he has better interface options on the DAC already.

 

[cjf]

My Meitner has no ST Input (it's the MA-1) so I've not tried it.

I'm curious what your configuration was while using USB that lead you to think its the worst way to connect a DAC? Ethernet is only better if optical isolation is used leading up to the LAN Input on the DAC otherwise your tied into a VERY noisy LAN which is riddled with low dollar SMPS wall warts from switches, routers and the like.

A measly 5v power leg found inside a USB cable is a joke compared to the crap traveling down an Ethernet cable which is plugged into mass produced Linksys switch or similar.

In my case I've gone overkill and used an Ethernet Opto isolator before the feed coming into my low watt music server which is powered by a laboratory grade adjustable linear power supply.

 

[Blizzard]

My Meitner has no ST Input (it's the MA-1) so I've not tried it.

I'm curious what your configuration was while using USB that lead you to think its the worst way to connect a DAC? Ethernet is only better if optical isolation is used leading up to the LAN Input on the DAC otherwise your tied into a VERY noisy LAN which is riddled with low dollar SMPS wall warts from switches, routers and the like.

A measly 5v power leg found inside a USB cable is a joke compared to the crap traveling down an Ethernet cable which is plugged into mass produced Linksys switch or similar.

In my case I've gone overkill and used an Ethernet Opto isolator before the feed coming into my low watt music server which is powered by a laboratory grade adjustable linear power supply.

Oh I guess I was confusing it with the Emm labs stuff. I've tried all kinds of USB interfaces. It was a real wake up call hearing the SD card transport on my Resonessence Mirus. And their USB implementation is one of the best out there. So I really started to research. Turns out very few industry leaders prefer USB. It's basically just there to allow connection to general purpose computers. It's also an easy way to accept high rez files. I'm getting some Ravenna boards soon so I'll be seeing how noise effects them vs fiber isolation. As I mentioned in earlier posts, as long as you have a low noise transceiver, Fiber can offer 100% isolation from noise without having to worry about jitter.

 

[BobShermanEsq]

How many albums do you have on 8tb? How would you deal with them in vinyl, cd or R2R? What would hold more tracks in a smaller footprint and be the easiest to manage?

Why answer a question with a question? How would you manage 8TBs on SD cards?

 

[BobShermanEsq]

Actually all the latest cutting edge DAC's either have Ethernet renderers built in or I2S inputs.

Really??? All the latest... Hmmm

is a result of Ed not caring much about USB because he has better interface options on the DAC already.

Ed??? Ae you on a first name basis with him also???

 

[BobShermanEsq]

Oh I guess I was confusing it with the Emm labs stuff. I've tried all kinds of USB interfaces. It was a real wake up call hearing the SD card transport on my Resonessence Mirus. And their USB implementation is one of the best out there. So I really started to research. Turns out very few industry leaders prefer USB. It's basically just there to allow connection to general purpose computers. It's also an easy way to accept high rez files. I'm getting some Ravenna boards soon so I'll be seeing how noise effects them vs fiber isolation. As I mentioned in earlier posts, as long as you have a low noise transceiver, Fiber can offer 100% isolation from noise without having to worry about jitter.

Is that the DAC you keep advertising for the manufacture? The designer of that DAC says the SD card and USB sound the same. Is he wrong, or not telling the truth?

Are you paying for the Ravenna Boards, or are they also comp for advertising?

 

[Blizzard]

Is that the DAC you keep advertising for the manufacture? The designer of that DAC says the SD card and USB sound the same. Is he wrong, or not telling the truth?

Are you paying for the Ravenna Boards, or are they also comp for advertising?

I actually work for every DAC manufacturer in the world who makes well engineered DAC's. I'm on the volunteer end of things.

 

[Blizzard]

Is that the DAC you keep advertising for the manufacture? The designer of that DAC says the SD card and USB sound the same. Is he wrong, or not telling the truth?

Are you paying for the Ravenna Boards, or are they also comp for advertising?

Yes they do say users had reported this. However they don't say that they agree.

 

[Blizzard]

Why answer a question with a question? How would you manage 8TBs on SD cards?

If you don't have the intelligence to figure that out, perhaps this option isn't for you.

 

[BobShermanEsq]

Yes they do say users had reported this. However they don't say that they agree.

No actually the designer said with the version 3 firmware they sound the same. That was reported as his opinion, not user opinions.

 

[Blizzard]

No actually the designer said with the version 3 firmware they sound the same. That was reported as his opinion, not user opinions.

Here's exactly what he says. And the reason they decided to update this section with this was because they figured out that it makes for much less headaches to tell people what they want to hear. But nowhere does it say it's their opinion. Only that it was reported to them:


Updated Notes: Prior to release 3 of our firmware, we got reports from beta-testers that the SD Card source ‘sounded better’ than USB, and we sought a reason for this in our design. It is hard to see why that would be, but experience teaches us to listen to our beta-testers and trust the feedback they give us, even if our design sense tells us that there should be no difference at all.

We note that since Release 3 this difference between USB and SD Card is no longer reported. But truth to tell, we did not actually even know how to address the problem since we could only identify second order effects (as described below) which are all already removed to the maximum extent we know how to implement. USB buffering which was a possible candidate for the source of imperfection, is not in our control since we are the client, not the host, on the USB bus.

However, Release 3 of the firmware is reported to have made SD Card and USB indistinguishable, and you may be interested to know what we did in Release 3 that seems to have serendipitously achieved this.

Release 3.0.0 and later firstly removed the ‘polling’ of the user interface and replaced it with interrupt-driven user input. This means that after the DSP has set up the USB processing paths and so forth, it no longer need keep checking for user interaction: it only responds when an actual user-interface event occurs.

Perhaps having more bearing on the issue, is that the software team found a redundant timing check in the USB data path and removed it. This timing check was ensuring a precise lock to the internal low phase noise clock, but it turns out that the data was already in that clock domain, hence this step was not necessary and removed.

Finally, FLAC decoding capability was added to the system. To achieve the real-time decompression ‘on-the-fly’ at 192kS/s was a significant challenge. Thankfully, we were able to do this in all INVICTAs that we have ever shipped, due to an op-code level optimization of the processor. That is, not relying on the compiler to give optimum operation code sequences, but actually examining them and hand-optimizing where a clear improvement was possible. We even went so far as to add additional hardware units to the processor to improve its op-code utilization. (This is possible since the processors in Resonessence products are the MicroBlaze reconfigurable processors from Xilinx). All this has led to a very efficient processor architecture that needs fewer clock cycles to complete common audio tasks.

These changes are now reported to make USB and SDCard exactly the same high quality audio. But, as you can see, it is unclear exactly where the fault was (if indeed there was one at all) and why Release 3 by all accounts has improved it.

 

[Whatmore]

No actually the designer said with the version 3 firmware they sound the same. That was reported as his opinion, not user opinions.

http://www.resonessencelabs.com/invicta/faq/#Can you say something about the Invicta USB Interface?

Updated Notes: Prior to release 3 of our firmware, we got reports from beta-testers that the SD Card source ‘sounded better’ than USB, and we sought a reason for this in our design. It is hard to see why that would be, but experience teaches us to listen to our beta-testers and trust the feedback they give us, even if our design sense tells us that there should be no difference at all.

We note that since Release 3 this difference between USB and SD Card is no longer reported.

sounds like user opinion to me

 

[Blizzard]

http://www.resonessencelabs.com/invicta/faq/#Can you say something about the Invicta USB Interface?



sounds like user opinion to me

BTW: Did you try out the SD card yet on your Invicta?

 

[Whatmore]

BTW: Did you try out the SD card yet on your Invicta?

yep, it's good... annoyingly good because I had all these plans of running my music through Roon!

Also, I need a user-friendly way of converting ALAC to FLAC

 

[Blizzard]

yep, it's good... annoyingly good because I had all these plans of running my music through Roon!

Also, I need a user-friendly way of converting ALAC to FLAC

Excellent. You'll notice after getting used to it going back to USB is a real disappointment.

If you ever want to upgrade the clock let me know. That's when you'll really notice the benefits with the SD card.

 

[BobShermanEsq]

Excellent. You'll notice after getting used to it going back to USB is a real disappointment.

If you ever want to upgrade the clock let me know. That's when you'll really notice the benefits with the SD card.

It is great that you have such a great ear and hear clock upgrades and the disappointing of USB.

Of course there can be no expectation bias involved in any of your opinions of your DIY upgrades and mods.

You must have some excellent speakers. Why can't you reveal what you are listening to?

They must be really great! Maybe something like Bose 901s???

 

[Blizzard]

yep, it's good... annoyingly good because I had all these plans of running my music through Roon!

Also, I need a user-friendly way of converting ALAC to FLAC

JRiver works good for that

 

[Blizzard]

It is great that you have such a great ear and hear clock upgrades and the disappointing of USB.

Of course there can be no expectation bias involved in any of your opinions of your DIY upgrades and mods.

You must have some excellent speakers. Why can't you reveal what you are listening to?

They must be really great! Maybe something like Bose 901s???

I have it hooked up to a Bose wave radio.