[Ultrainferno]

I created this topic to discuss the brand new Violectric DAC V850
 
Quote:

  Violectric to introduce a new D/A converter: DAC V850




 

 
 
Violectric will introduce a new D/A converter during the May 2015 HiEnd exhibition in Munich Germany.
 
The case and the front panel will share the familiar look of our well known DAC V800.
 
The DAC V850 features 4 digital inputs: balanced AES/EBU via XLR, coaxial SPDIF via RCA, optical via
Tos-Link, and Asynchronous USB. All inputs are capable of PCM up to 24 bits at 192 kHz.

Topology:

The digital signal is first routed to re-sampling circuitry where virtually all incoming jitter is eliminated.
Then up to 4 times up-sampling can be selected from the front panel.
This process can be completely disabled or set to “best” operation which means that all incoming digital signals will be normalized to 96 kHz.
We have found this to be the optimal frequency to achieve the best audio quality when re-sampling lower bit rate data.

A digital output is also provided which mirrors either the active input signal or the digital signal that has been processed by the re-sampler.
Our design features a 32 bit double mono converter architecture which consists of two 32 bit (PCM1795) converters for each channel.
This serves to enhance the dynamic range and minimize distortion.

The analog output circuitry is fully balanced from the D/A converters to the analog outputs.
This is very similar to the circuitry design we used in the DAC V800 but, with further refinement in the output stage.
The maximum balanced analog output level may be set internally to +24 / +18 / +15 / +12 / or +6 dBu to ensure a perfect match with your other equipment.
The unbalanced analog outputs will always be 9 dB lower compared to the balanced output setting.

The volume control is again all digital just like we used in the DAC V800.
There is no scratching, no channel imbalance, and no reduced crosstalk which can be the case with an analog volume implementation.
This is why we prefer digital all the way through our design. Yes, there is some reduced resolution when lowering the volume.
However since we first up-sample the input to 32 bits we have at least 8 bits with no definitive content.
This gives us 8 x 6 = 48 dB of gain reduction available to lower the output volume and prevents any degradation of the original digital signal.

The DAC V850 may be equipped with an optional remote control for volume and input selection.
A motor driven potentiometer serves to set the attenuation.

The DAC V850's front panel will be available in BLACK  and SILVER.

The estimated price will be around 1175 Euro excl. VAT, the remote control option adds 210 Euro excl. VAT.

 

 

[Ultrainferno]

I liked the original V800, I look forward to listening to the V850 in combination with my V281. Edit: Review is online

 

[mulder01]

Also:
 
Quote:

 
 
The differences between V800 and V850 are more evolution than revolution.
I don´t think that there can be a revolution concerning DACs these days.
But the differences are more than cosmetical.

First, the base of the USB circuitry is not Tenor any more but X-Mos based.
So we are sure to have a software support also for upcoming OS like Windows 10.

Second, we now have a double-mone architecture with two converters per channel.
This will not be noticeable in therms of THD or SNR but it sharpens our philosophy "no sound".
V850 is more open, more detailed, has a bigger and deeper soundstage but still retains a maximum neutrality compared with V800.
For our opinion all this is not due to the 32 bit deep conversion but has its source in the dual converters per channel and our refined analog output circuitry.
To be honest, 32 bit deep processing is useful in mixing consoles or other equipment where data is merged, filters and equalisers are set or rooms are created.
In a D/A converter, at the endpoint of digital data, it is nice to have but nothing more.

Third, there had been lots of customers asking for a remote control in the past because our D/A served to drive (active) speakers directly.
DAC V850 offers the opportunity to be remote controlled !
 
And of course there is a better power supply, better signal tracing and much more details.

Other things which made V800 famous will remain:
- The compact size
- The range of digital inputs
- The selectable range of resampling
- The volume control in the digital domain
- Five different analog output voltage settings without affecting the output impedance
- Balanced and unbalanced outputs which can be used simultaneously because they have their own drivers
 

 

 

[project86]

Fried, can you clarity the total number of PCM1795 chips on board? I'm thinking two of them total, which is how the "dual mono" term is usually applied. But it gets confusing to think of "two converters per channel". Because that could mean two separate PCM1795's per channel (for a total of four DAC chips on board) or it could mean one PCM1795 chip per channel, each being a stereo chip. It's confusing even to phrase the question!
 
I find this often when using the 8-channel ESS DACs. The press release will mention 8 DACs on board, or quad DACs per channel, which is true... but not quite the same as having 8 ES9018 chips total. 
 
Not that this really makes a huge difference either way. 

 

[rx79ez08]

From the spec, I assume no DSD capability?

 

[Ultrainferno]

  From the spec, I assume no DSD capability?

 
That's correct. No native DSD

 

[Zkadoush]

  Also:
 

 
It may not be revolution, but on the evolution side it is a significant improvement over the V800. Very interesting and welcome indeed!

Sorry for not having thought of opening a new thread to ask the questions in the right space. I'll just reiterate my last question from the V281 thread, as the first ones were answered:

"You have mentioned before in the V281 thread that both you and John Siau - from Benchmark - prioritize THD and linearity over SNR. I believe this is an important aspect to understand, could you perhaps elaborate a bit more on that topic?"

I'll add the following question:

"The Benchmark DAC2 series includes an interesting feature, which is the 3,5 dB high-headroom DSP. Is this a significant feature that would be worth implementing in the V850?

Congrats on the release of the V850, will be getting in line for my own unit.

Cheers!

 

[mulder01]

   
It may not be revolution, but on the evolution side it is a significant improvement over the V800. Very interesting and welcome indeed!

 

 
If it's not a significant improvement, at least the last few v800s should go for pretty cheap

 

[fdg]

@ Ultrainferno - thank you

@ project86
We have 1 PCM1795 per channel. This DAC includes 2 converters, normally used for left and right.
We take them for one channel.

@ rx79ez08  
I admit: I hate DSD
DSD came up in the middle of the 90ties in the professional world.
Why ? I guess because there had to be something new ...
There is definetely no practical reason to go for DSD and therefore this format is dead since a long time in the recording industry.

The biggest disadvantage of DSD (there are many more) is: it can´t be edited.
So, if there is a real DSD recording it is converted to PCM before it enters the mixing console or the editing suite.
After the necessary steps are made it is back converted into DSD.
Does this really make sense ??
And to make a DSD file out of a PCM file is as senseful as upsampling a CD because of the sound ...
 
Well, the above is my personal opinion but there is also a practical one:
We have learned that a DSD data stream can´t be modified and so it is not possible to attenuate such signals in the digital domain.
As we have implemented the volume control on the digital side there is no way to process DSD data
 

@ Zkadoush
Yes, low THD and linearity are the specs we are hunting for. SNR is only the vehicle to get there.
Why that?
It is not possible to have 100 dB THD (0,001%) with 90 dB SNR, but it is possible to have 110 dB THD (0,0003%) with 120 dB SNR.

High SNR values are relatively easy to achieve as they only describe the difference between fully off and fully on.
Some manufacturers of D/A chips include the mute state in their data to rise SNR.
The SNR of the D/A chip itself is always higher than the SNR measured at the outputs of a specific device because unlinearities and noise will be added from the analog circuitry.
There had been a time when a German manufacturer constructed a 28 bit D/A converter with a sensational high SNR of over 150 dB.
This was accomplished with two stagged 18 bit converters and a switching point at -60 dB.
As only 18 bit converters had been involved with relatively poor THD figures it took a while until people realized that highest SNR is no garantee for a good sound.

Good sound is achieved by low THD - it describes how exact a sound can be depicted.

24 bit digital data means a maximum SNR of 144 dB what is far more than nature can offer.
So theoretically it could be possible to have a THD as low as 140 dB.
The real world THD from a good A/D converter is a low as -110 dB and it will take lots of efforts to lower it to -115 dB one day.
More is not possible for my opinion.
Please always keep in mind that dB describes a logarithm ratio.
So the difference between 80 and 100 dB is not "just 20 more" but describes a ration of 1:10.000 (80 dB) and 1:100.000 (100 dB) which is a significant difference.    
A really good D/A converter (like V800) offers -112 dB THD.
As there is also noise generated from the analog output circuitry there is also THD+N(oise) which is always lower compared to THD.
In case of V800 THD+N is -108 dB.

Concerning the "3.5 dB high headroom DSP" from Benchmark I can´t tell you something about.
Also there is no explanation to find on the web.
For me 0 dBFs is the maximum you can achieve as there are no positive dB values with digital data.
So the question is what this headroom is good for. Maybe John Siau will explain some day.
 
Thank you,
 
Fried

 

[rx79ez08]

  @ rx79ez08  
I admit: I hate DSD
DSD came up in the middle of the 90ties in the professional world.
Why ? I guess because there had to be something new ...
There is definetely no practical reason to go for DSD and therefore this format is dead since a long time in the recording industry.

The biggest disadvantage of DSD (there are many more) is: it can´t be edited.
So, if there is a real DSD recording it is converted to PCM before it enters the mixing console or the editing suite.
After the necessary steps are made it is back converted into DSD.
Does this really make sense ??
And to make a DSD file out of a PCM file is as senseful as upsampling a CD because of the sound ...
 
Well, the above is my personal opinion but there is also a practical one:
We have learned that a DSD data stream can´t be modified and so it is not possible to attenuate such signals in the digital domain.
As we have implemented the volume control on the digital side there is no way to process DSD data
 

I guess that is a matter of personal opinion. I have enough DSD in my music collection that it would be nice to be able to play them natively. At the very least I found that DSD records to be generally mastered in a better quality.
 
On a related matter, now that the USB issue have been sorted, are there going to be a program to exchange the DAC of people who have brought the old 192kHz USB DAC card? I got one of those that i purchased with my V281 when it first came out. I can never get the DAC to work properly with my setup. I just though it is my own problem until I read into it. Now that the chip won't even work with a newer OS, it is rather disappointing for a card that is less than a year old.

 

[mulder01]

Quote:

The biggest disadvantage of DSD (there are many more) is: it can´t be edited.
So, if there is a real DSD recording it is converted to PCM before it enters the mixing console or the editing suite.
After the necessary steps are made it is back converted into DSD.
Does this really make sense ??

 
Wow, never knew that.  So I guess that means the only reason it sounds better is because they took time time to record it better and has nothing to do with the format...

 

[Zkadoush]

  @ Ultrainferno - thank you

@ project86
We have 1 PCM1795 per channel. This DAC includes 2 converters, normally used for left and right.
We take them for one channel.

@ rx79ez08  
I admit: I hate DSD
DSD came up in the middle of the 90ties in the professional world.
Why ? I guess because there had to be something new ...
There is definetely no practical reason to go for DSD and therefore this format is dead since a long time in the recording industry.

The biggest disadvantage of DSD (there are many more) is: it can´t be edited.
So, if there is a real DSD recording it is converted to PCM before it enters the mixing console or the editing suite.
After the necessary steps are made it is back converted into DSD.
Does this really make sense ??
And to make a DSD file out of a PCM file is as senseful as upsampling a CD because of the sound ...
 
Well, the above is my personal opinion but there is also a practical one:
We have learned that a DSD data stream can´t be modified and so it is not possible to attenuate such signals in the digital domain.
As we have implemented the volume control on the digital side there is no way to process DSD data
 

@ Zkadoush
Yes, low THD and linearity are the specs we are hunting for. SNR is only the vehicle to get there.
Why that?
It is not possible to have 100 dB THD (0,001%) with 90 dB SNR, but it is possible to have 110 dB THD (0,0003%) with 120 dB SNR.

High SNR values are relatively easy to achieve as they only describe the difference between fully off and fully on.
Some manufacturers of D/A chips include the mute state in their data to rise SNR.
The SNR of the D/A chip itself is always higher than the SNR measured at the outputs of a specific device because unlinearities and noise will be added from the analog circuitry.
There had been a time when a German manufacturer constructed a 28 bit D/A converter with a sensational high SNR of over 150 dB.
This was accomplished with two stagged 18 bit converters and a switching point at -60 dB.
As only 18 bit converters had been involved with relatively poor THD figures it took a while until people realized that highest SNR is no garantee for a good sound.

Good sound is achieved by low THD - it describes how exact a sound can be depicted.

24 bit digital data means a maximum SNR of 144 dB what is far more than nature can offer.
So theoretically it could be possible to have a THD as low as 140 dB.
The real world THD from a good A/D converter is a low as -110 dB and it will take lots of efforts to lower it to -115 dB one day.
More is not possible for my opinion.
Please always keep in mind that dB describes a logarithm ratio.
So the difference between 80 and 100 dB is not "just 20 more" but describes a ration of 1:10.000 (80 dB) and 1:100.000 (100 dB) which is a significant difference.    
A really good D/A converter (like V800) offers -112 dB THD.
As there is also noise generated from the analog output circuitry there is also THD+N(oise) which is always lower compared to THD.
In case of V800 THD+N is -108 dB.

Concerning the "3.5 dB high headroom DSP" from Benchmark I can´t tell you something about.
Also there is no explanation to find on the web.
For me 0 dBFs is the maximum you can achieve as there are no positive dB values with digital data.
So the question is what this headroom is good for. Maybe John Siau will explain some day.
 
Thank you,
 
Fried

Hi Fried,

Thanks a lot for your detailed response regarding the relation between TDH and SNR, highly appreciated! It makes good and very important points.

I also appreciate your frank comments regarding DSD. The inherent flaws of DSD have been widely documented, but for obvious reasons, like marketing, hype and money, DSD has managed to stay in the game, and now ther's even this website to buy native DSD recordings, lol: https://www.nativedsd.com/
For anyone interested in the topic I'd recommend this little reading (and a few other ones that can be found at Mark Waldrep's REAL HD-Audio Blog) :

http://www.realhd-audio.com/?p=74

Regarding a little history about how DSD came to be, here's Mark Waldrep's take on it in 3 parts:

http://www.realhd-audio.com/?p=3772
http://www.realhd-audio.com/?p=3779
http://www.realhd-audio.com/?p=3782

Regarding the "3.5 dB high headroom DSP" Implemented in Benchmarks DAC2 series, the product page of the DAC2 states the following:

"All D/A converters need 3.5 dB "excess" digital headroom, but few have any headroom above 0 dBFS.

All of the digital processing in the DAC2 DX is designed to handle signals as high as +3.5 dBFS. Most digital systems clip signals that exceed 0 dBFS. The 0 dBFS limitation seems reasonable, as 0 dBFS is the highest sinusoidal signal level that can be represented in a digital system. However, a detailed investigation of the mathematics of PCM digital systems will reveal that inter-sample peaks may reach levels slightly higher than +3 dBFS while individual samples never exceed 0 dBFS. These inter-sample overs are common in commercial releases, and are of no consequence in a PCM system until they reach an interpolation process. But, for a variety of reasons, virtually all audio D/A converters use an interpolation process. The interpolation process is absolutely necessary to achieve 24-bit state-of-the art conversion performance. Unfortunately, inter-sample overs cause clipping in most interpolators. This clipping produces distortion products that are non-harmonic and non-musical . We believe these broadband distortion products often add a harshness or false high-frequency sparkle to digital reproduction. The DAC2 DX avoids these problems by maintaining at least 3.5 dB of headroom in the entire conversion system.

We believe this added headroom is a groundbreaking improvement delivering significant sonic advantages."

More detailed explanations and graphs behind the reasons to implement the 3.5 dB high headroom DSP can be found in two application notes at the Benchmark website, written by John Siau:

http://benchmarkmedia.com/blogs/news/13545433-audio-that-goes-to-11
http://benchmarkmedia.com/blogs/news/13740017-why-audio-goes-to-11

Any thoughts?

Thanks again for your answers, very much looking forward to the release of the V850 DAC.

Cheers!
 

 

[hmouse]

Is it possible to bypass the volume control?

 

[gogogasgas]

Q: Is it possible to bypass the volume control?
 
A: Putting the volume control to full (OK, my answer is a guess. But, it's what you should do on a Mac when using it's TOSLINK output connected to a DAC, perhaps it's the same for the digital volume of the V850)

 

[gogogasgas]

Reading the last few posts on the V800 thread, Fried said:
 
"Out of a sudden by the end of 2014 they discontinued the production of the chips and the software support …  
We, as well as many others, had been left outside standing in the rain."
 
So, does this mean that V850 will REPLACE the V800 in the lineup, or is there another upgrade for the V800 (version 3?) coming out that will rectify the above issues?