[wolfgang0119]

   
DSD to PCM conversion using foobar is applicable to other regular PCM DAC.  Meaning, this statement on NuForce website:
"Supports PCM and DSD over USB playback (DSD support on PC only)"
Is misleading as the DAC is not natively support DSD conversion, and the DSD signal is 'NEVER' transfer over the USB connection between DAC and PC, only PCM data is transfer over USB.
Am I right to say that?

 
No, the DSD stream is transferred to the USB chip and the USB chip does the real-time conversion to PCM before passing on to the DAC chip. I confirmed this with our RD.

 

[earfonia]

   
No, the DSD stream is transferred to the USB chip and the USB chip does the real-time conversion to PCM before passing on to the DAC chip. I confirmed this with our RD.

 
I see.  Great!  Thanks for the clarification!
Than Icon DAC is indeed a very interesting DAC + Amp combo !!!
I would like to hear how it drives the orthodynamic headphones with it powerful headphone amp

 

[wolfgang0119]

   
I see.  Great!  Thanks for the clarification!
Than Icon DAC is indeed a very interesting DAC + Amp combo !!!
I would like to hear how it drives the orthodynamic headphones with it powerful headphone amp

 
Hi earfonia,
 
After I reply to you our RD send me a correction o_0  Here's what he said:
 
The previous statement is wrong. The DSD conversion happens in the ASIO driver layer.
The sound is clearly improvement by specific ASIO driver.
I think user will hear the different between DSD and PCM playback.
 
So you're right but the sound should be different. 

 

[earfonia]

   
Hi earfonia,
 
After I reply to you our RD send me a correction o_0  Here's what he said:
 
The previous statement is wrong. The DSD conversion happens in the ASIO driver layer.
The sound is clearly improvement by specific ASIO driver.
I think user will hear the different between DSD and PCM playback.
 
So you're right but the sound should be different. 

 
I see, I really appreciate your clarification!
But in this case, since the DSD conversion is done in computer, the DSD support is not specific to the DAC.  Therefore any regular PCM DAC would benefit from the same method.
It is not the sound quality that bothers me, it is the statement:
"Supports PCM and DSD over USB playback (DSD support on PC only)"
IMHO, it is misleading since the DSD signal is 'Never' transfered over the USB connection, and the DSD conversion to PCM has nothing to do with the DAC.
I suggest to avoid confusion, nuForce shouldn't put that statement of 'DSD over USB playback' as one of the feature of the DAC, as it is not true

 

[Speakerphile]

   
Hi earfonia,
 
After I reply to you our RD send me a correction o_0  Here's what he said:
 
The previous statement is wrong. The DSD conversion happens in the ASIO driver layer.
The sound is clearly improvement by specific ASIO driver.
I think user will hear the different between DSD and PCM playback.
 
So you're right but the sound should be different. 

 
I agree.  If this is true, it is very misleading.  It borders of false advertisement.  Very disappointing, and now calls into question DSD support on all NuForce products.  This is not a good way to get the respect of the audiophile community.  By the same standard, nearly any USB DAC could be made to "support" DSD.  

 

[wolfgang0119]

Here's our RD's reply regarding to your question:
 
Direct-Stream Digital is simply a 1-bit digital audio format that is based on the Sigma-Delta encoding/decoding architecture, and in practice is commonly referred to as a DSD recording/file.
 
Many are not aware though that whether they are employed in the processing of PCM or DSD signals, all modern DAC chips are actually based on the same basic 1-bit Sigma-Delta architecture. In short, the only real question is whether we're sending a PCM or DSD signal to be decoded by a Sigma-Delta DAC.
 
With respect to PCM, the incoming data is first converted into a 1-bit Sigma-Delta signal internally and then it is processed by a following Low-Pass Filter stage. In the case of DSD, the signal is directly decoded by the DAC, which skips the Sigma-Delta conversion part of the process and then utilizes the Low-Pass Filter stage.  The difference between the two formats is like comparing 10 dimes with a 1-dollar bill and trying to determine which is better.  In one case where you have just a coin purse, 10 dimes is better. In the case where you have a wallet though, the dollar bill is preferable. In either case though, you still have the exact same amount of currency.
 
Therefore, no matter how you view it DSD and PCM are nothing more than different ways of looking at the exact same thing. While there are differences, where and when the data is converted is of little practical importance with respect to the end result.
 
However, one should note that the DSD format was originally developed to facilitate conversion to the 44.1kHz CD standard; hence, the PCM equivalent of a 2.8Mhz DSD file would be manifest as an 88.2kHz file at 20-bit resolution.  Compared to a 24-bit PCM file, DSD delivers a dynamic range that is actually 24dB less. Similarly, a "double" 5.6Mhz DSD file is the equivalent of a PCM file recorded at 176.4kHz and 20-bit resolution.

 

[Speakerphile]

  Here's our RD's reply regarding to your question:
 
Direct-Stream Digital is simply a 1-bit digital audio format that is based on the Sigma-Delta encoding/decoding architecture, and in practice is commonly referred to as a DSD recording/file.
 
Many are not aware though that whether they are employed in the processing of PCM or DSD signals, all modern DAC chips are actually based on the same basic 1-bit Sigma-Delta architecture. In short, the only real question is whether we're sending a PCM or DSD signal to be decoded by a Sigma-Delta DAC.
 
With respect to PCM, the incoming data is first converted into a 1-bit Sigma-Delta signal internally and then it is processed by a following Low-Pass Filter stage. In the case of DSD, the signal is directly decoded by the DAC, which skips the Sigma-Delta conversion part of the process and then utilizes the Low-Pass Filter stage.  The difference between the two formats is like comparing 10 dimes with a 1-dollar bill and trying to determine which is better.  In one case where you have just a coin purse, 10 dimes is better. In the case where you have a wallet though, the dollar bill is preferable. In either case though, you still have the exact same amount of currency.
 
Therefore, no matter how you view it DSD and PCM are nothing more than different ways of looking at the exact same thing. While there are differences, where and when the data is converted is of little practical importance with respect to the end result.
 
However, one should note that the DSD format was originally developed to facilitate conversion to the 44.1kHz CD standard; hence, the PCM equivalent of a 2.8Mhz DSD file would be manifest as an 88.2kHz file at 20-bit resolution.  Compared to a 24-bit PCM file, DSD delivers a dynamic range that is actually 24dB less. Similarly, a "double" 5.6Mhz DSD file is the equivalent of a PCM file recorded at 176.4kHz and 20-bit resolution.

 
All of this is fine, but it's really not the issue.  I wasn't trying to ascertain which one was ideal.  I was simply saying that due to the nature of the conversion, and where it takes place in this case, you really shouldn't be claiming to have a DSD-compatible DAC.  It's kind of like saying that my car runs on crude oil, as long as I refine it to unleaded gasoline first.  Please correct me if I am interpreting this wrong.  It just sounds like in using this method, nearly all current DAC's could be said to "support" DSD with a new driver.       

 

[earfonia]

  Here's our RD's reply regarding to your question:
 
...While there are differences, where and when the data is converted is of little practical importance with respect to the end result...

 
I agree with that statement.
 
But your R&D missed the point here...  We never argue about the END RESULT!
End result is not the point of argument!  What we are trying to say is, if the DSD conversion is done on PC, that you guys shouldn't put the statement "Supports PCM and DSD over USB playback" as one of the DAC feature, because the DSD signal is not transmitted over the USB connection and DSD conversion is not happening in the DAC !  That statement of "Supports PCM and DSD over USB playback" as one of the DAC feature is a false advertisement!
 
The statement could be changed to something like: DSD encoding is supported by PC application.

 

[wolfgang0119]

   
I agree with that statement.
 
But your R&D missed the point here...  We never argue about the END RESULT!
End result is not the point of argument!  What we are trying to say is, if the DSD conversion is done on PC, that you guys shouldn't put the statement "Supports PCM and DSD over USB playback" as one of the DAC feature, because the DSD signal is not transmitted over the USB connection and DSD conversion is not happening in the DAC !  That statement of "Supports PCM and DSD over USB playback" as one of the DAC feature is a false advertisement!
 
The statement could be changed to something like: DSD encoding is supported by PC application.

 
Unless special DSD to PCM conversion software is first installed on the PC and used to convert and then store the resulting PCM file on the hard drive, then normally the DSD conversion process will not take place. This only makes sense.
 
Conversely, the conversion process supported by the Icon DAC takes place "on demand" and in "quasi-real time" under control of Foobar 2000. Therefore, the resulting PCM data after conversion must be transferred directly to the Icon DAC from the PC with strict control of transfer timing ("handshaking"), etc. Proper communication for this complete process to take place requires that the USB chip in any external DAC must be able to communicate back-and-forth with the PC, and be ready to receive the data as it is converted and sent/received in the general form:
 
Foobar 2000 > CPU > ASIO DSD driver > CPU > UART in computer USB bus > USB chip in External DAC > UART in computer USB bus > CPU > etc.
 
If the USB chip in the External DAC does not have this ability/does not support DSD playback, then the PC cannot/will not perform the conversion.
 
Example: Try playing back a DSD file via Foobar 2000 into an external DAC that DOES NOT support DSD playback of the type that the Icon DAC DOES... without first manually converting the file to PCM by using special conversion software that you must purchase and install on your computer separately. You will hear nothing... except maybe noise.

 

[Armaegis]

Is the DSD playback limited exclusively to foobar or can other programs utilize it with proper drivers/plugins?

 

[earfonia]

   
Unless special DSD to PCM conversion software is first installed on the PC and used to convert and then store the resulting PCM file on the hard drive, then normally the DSD conversion process will not take place. This only makes sense.
 
Conversely, the conversion process supported by the Icon DAC takes place "on demand" and in "quasi-real time" under control of Foobar 2000. Therefore, the resulting PCM data after conversion must be transferred directly to the Icon DAC from the PC with strict control of transfer timing ("handshaking"), etc. Proper communication for this complete process to take place requires that the USB chip in any external DAC must be able to communicate back-and-forth with the PC, and be ready to receive the data as it is converted and sent/received in the general form:
 
Foobar 2000 > CPU > ASIO DSD driver > CPU > UART in computer USB bus > USB chip in External DAC > UART in computer USB bus > CPU > etc.
 
If the USB chip in the External DAC does not have this ability/does not support DSD playback, then the PC cannot/will not perform the conversion.
 
Example: Try playing back a DSD file via Foobar 2000 into an external DAC that DOES NOT support DSD playback of the type that the Icon DAC DOES... without first manually converting the file to PCM by using special conversion software that you must purchase and install on your computer separately. You will hear nothing... except maybe noise.

 
Well, how do you explain the SACD plugin for foobar?
http://sourceforge.net/projects/sacddecoder/
 

 
 
I have used it to play SACD ISO and DSD files on common PCM DAC, including notebook's build-in soundcard.
The SACD decoder plugin converts the DSD files to PCM in 'Real Time'.
 
Does NuForce supplying other special foobar plugin for NuForce DAC?  
Still, it doesn't qualify the DAC to claim "DSD over USB playback" feature.

 

[Speakerphile]

   
Unless special DSD to PCM conversion software is first installed on the PC and used to convert and then store the resulting PCM file on the hard drive, then normally the DSD conversion process will not take place. This only makes sense.
 
Conversely, the conversion process supported by the Icon DAC takes place "on demand" and in "quasi-real time" under control of Foobar 2000. Therefore, the resulting PCM data after conversion must be transferred directly to the Icon DAC from the PC with strict control of transfer timing ("handshaking"), etc. Proper communication for this complete process to take place requires that the USB chip in any external DAC must be able to communicate back-and-forth with the PC, and be ready to receive the data as it is converted and sent/received in the general form:
 
Foobar 2000 > CPU > ASIO DSD driver > CPU > UART in computer USB bus > USB chip in External DAC > UART in computer USB bus > CPU > etc.
 
If the USB chip in the External DAC does not have this ability/does not support DSD playback, then the PC cannot/will not perform the conversion.
 
Example: Try playing back a DSD file via Foobar 2000 into an external DAC that DOES NOT support DSD playback of the type that the Icon DAC DOES... without first manually converting the file to PCM by using special conversion software that you must purchase and install on your computer separately. You will hear nothing... except maybe noise.

 
This is quite troubling.  To me, this is not "DSD-Support".  Basically any DAC with ASIO driver support should support this "feature".
 
One follow-up question as well.  Should we expect this same DSD implementation in all NuForce products that are advertised with DSD support, including the uDAC-3?

 

[Armaegis]

Hmm just noticed this thing has a different DC power input from the other products in the Icon line. That's a shame that it can't be used with your LPS power supply.
 
Or is it compatible with higher voltage input? I assume you have voltage regulators and multipliers in there since to get the rated headphone power output you'd need voltage rails greater than the 6.5V indicated on the DC jack.

 

[BF3 Player]

Sorry to dig up this old thread. I just purchased this dac however the AC adapter that came with it is faulty, so are there any alternatives that will work in place of the factory original? 

 

[Armaegis]

If it's faulty they should be able to replace it for you.