My 2 cents.
Sigma Delta - E d. Ok I cannot write the mathermatical symbols here. What this means mathameticall is to add up all (Sigma = summation) of all the small changes (delta).
DSD is just adding those changes digitally to the prior voltage level and then smoothing it out using a low pass filter. Not complicated. What makes it complicated is the noise and the prior voltage level.
PCM is a absolute sample of the full voltage level at a particular interval. 24bit/192khz is the 24 bit absolute digital representation of the signal taken every 192,000 times a second. The PCM signal does not rely on the last voltage level to decide on the current level. A low pass filter is also used to clean out noise although a low pass is critical in the beginning.
So the difference in sound, from a pure mathematical standpoint should theoretically be the same, however Sigma Delta was invented to do a better job a very long time ago for data acquisition. This was when chips, computers etc was very expensive and bits were not freely available.
The sound differences heard is many times in the implementation more than the technology for both high res (DXD, 2DXD). For lower res, there are bigger differences - 16 bits, versus big transient changes if you have a low sampling rate on Sigma Delta.
So the over sampling of the same signal, 10 times, will give you the same signal 10 times. Ok you might get some error correction if a bit was dropped somehow. This new 10 times signal is then converted to another format and/or to analog. What each company ( not technology) is doing is trying to extrapolate the forward bits from the previous bits. This is where the playback seems different.
Then there are the filters put in, which again provides some differences.
If all the conversion on PCM DXD and 2DSD is perfect for the DAC software or hardware, then the important factors for accurate playback is how stable and noisy the power supply is and how good the clock is. I believe this is really what makes a good DAC, if all else is perfect.
So the PS Audio Direct Stream may have an excellent algorithm or it may be the same as Meitner and Koch (fathers of DSD), the above 2 factors will determine the accuracy.
As with everything, preference become the final choice - Too smooth or too sharp?
So PCM and DSD are sort of very different digital representations of the same signal.
Converting FLAC to WAV are both supposed to be identical. However some, TAS for one, has said there is a difference.
As you get to higher and higher resolutions, there are fewer and fewer gaps. On the lower levels, say 16 bits, there would be greater gaps with doing the conversion from one to the other. This is true of almost any conversation.
So I don't have a definitive answer to PCM or DSD, or will the conversion provide any new information (I personally cannot see how information can be made up). But I do have a preference for DSD and in the comparison of a PCM DAC to a DSD DAC, everyone preferred the DSD DAC - when the test was only about the sound and which DAC was better. Nobody was made overtly aware that it was a DSD DAC playing PCM files (since the PCM DAC could only play PCM). We were using 24/192 files.
So the 2nd point is that the DAC's should be compared directly without thought of the underlying technology as you will be playing both files. Just like Cell phones, do you care if it is GSM or CDMA or TDMA? You probably don't even know but have a preference for various reasons. Of course if you have dominatly one type, then that should be the file choice for testing the best DAC for you.
Hopefully I will be able to get this DAC and compare it against a few other DAC's in the near future, assuming PS Audio delivers on time to the overwheming order load they have.
Sigma Delta - E d. Ok I cannot write the mathermatical symbols here. What this means mathameticall is to add up all (Sigma = summation) of all the small changes (delta).
DSD is just adding those changes digitally to the prior voltage level and then smoothing it out using a low pass filter. Not complicated. What makes it complicated is the noise and the prior voltage level.
PCM is a absolute sample of the full voltage level at a particular interval. 24bit/192khz is the 24 bit absolute digital representation of the signal taken every 192,000 times a second. The PCM signal does not rely on the last voltage level to decide on the current level. A low pass filter is also used to clean out noise although a low pass is critical in the beginning.
So the difference in sound, from a pure mathematical standpoint should theoretically be the same, however Sigma Delta was invented to do a better job a very long time ago for data acquisition. This was when chips, computers etc was very expensive and bits were not freely available.
The sound differences heard is many times in the implementation more than the technology for both high res (DXD, 2DXD). For lower res, there are bigger differences - 16 bits, versus big transient changes if you have a low sampling rate on Sigma Delta.
So the over sampling of the same signal, 10 times, will give you the same signal 10 times. Ok you might get some error correction if a bit was dropped somehow. This new 10 times signal is then converted to another format and/or to analog. What each company ( not technology) is doing is trying to extrapolate the forward bits from the previous bits. This is where the playback seems different.
Then there are the filters put in, which again provides some differences.
If all the conversion on PCM DXD and 2DSD is perfect for the DAC software or hardware, then the important factors for accurate playback is how stable and noisy the power supply is and how good the clock is. I believe this is really what makes a good DAC, if all else is perfect.
So the PS Audio Direct Stream may have an excellent algorithm or it may be the same as Meitner and Koch (fathers of DSD), the above 2 factors will determine the accuracy.
As with everything, preference become the final choice - Too smooth or too sharp?
So PCM and DSD are sort of very different digital representations of the same signal.
Converting FLAC to WAV are both supposed to be identical. However some, TAS for one, has said there is a difference.
As you get to higher and higher resolutions, there are fewer and fewer gaps. On the lower levels, say 16 bits, there would be greater gaps with doing the conversion from one to the other. This is true of almost any conversation.
So I don't have a definitive answer to PCM or DSD, or will the conversion provide any new information (I personally cannot see how information can be made up). But I do have a preference for DSD and in the comparison of a PCM DAC to a DSD DAC, everyone preferred the DSD DAC - when the test was only about the sound and which DAC was better. Nobody was made overtly aware that it was a DSD DAC playing PCM files (since the PCM DAC could only play PCM). We were using 24/192 files.
So the 2nd point is that the DAC's should be compared directly without thought of the underlying technology as you will be playing both files. Just like Cell phones, do you care if it is GSM or CDMA or TDMA? You probably don't even know but have a preference for various reasons. Of course if you have dominatly one type, then that should be the file choice for testing the best DAC for you.
Hopefully I will be able to get this DAC and compare it against a few other DAC's in the near future, assuming PS Audio delivers on time to the overwheming order load they have.
You are just a glutton for punishment!
