With -60dB the noise is basically the same. With DSD64 in Mono 9V OP mode the DR will be -130dB. With DSD256 it will reach the chips max of > -132dB. This is far in excess of 16 bit NF. So the format itself is capable of huge DR in audio band. Conversion software and hardware is another issue.
-
Welcome to ASR. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!
Octave Music Don Grusin High Resolution Music Analysis (Video)
- Thread starter amirm
- Start date
An amusing excuse. Did the datasheet mention the graph you posted is from DSD64 or DSD256?
Since you edited your post...
I was clearly commenting Miska's RME AKM DAC measurement results, and it is totally irrelevant to how you interpret the TI datasheet.
Last edited:
It has been explained to me that the PCM format may have problems with: glitches, idle tones and some imaging at low levels at a few hundred kilohertz or in the megahertz range. What other problems are there with PCM that I am missing? Ringing? There is incredible technological firepower on display in this thread, but no one has explained why we need to ‘improve’ the PCM format. If someone could explain in a couple of sentences what the problem with PCM is that must be addressed, I will leave this thread a happy man. If the problem with PCM cannot be identified, then there is no need to look for a solution, whether it be DSD or some as yet undiscovered new format.
Happy Listening!
PEACE
Happy Listening!
PEACE
Idle tones are a DSD problem.
All DSD measurements in the data sheet are at 64x. In the TI forum, application Engineers couldn't guarantee that it will run higher than DSD64.
However this DAC has successfully been used by people at DSD256 rates and the max DSD clocking spec supports this.
Maybe you could cut the condescending approach and take note that I have spoken to product application engineers and other designers
WRT what this chip can and can't do.
This forum is clearly very anti DSD amongst other things. I'm neither a proponent or a detractor but I do like to understand what it is
capable of and how to best work with it.
TCD
Then don't post that graph in the first place.
What are the other ’problems’ that would be associated with PCM that need to be solved or improved upon?
thnx
???? Surely you understand that whatever the NF is at DSD64, it will be lower at DSD256.
You clearly stated that "DSD256 is still noisier than 44.1k PCM". I'm at a bit of a loss why but maybe it
was a response to Miska's input which seems to have polarized a lot of people here.
TCD
Octave Music Don Grusin High Resolution Music Analysis (Video)
Oh, I fully understand their architecture. Just because there is noise shaping in majority of ADCs does not mean at all that they equal DSD64 1-bit encoding. Easy to prove. Here is RME ADI-2 Pro FS being fed a 1 kHz tone at 96 kHz sampling: Oh yes, ADI-2 Pro, with 44.1 kHz PCM input: You...
View attachment 196694
It is amusing that everyone put the focus on ultrasonic noise without paying attention to stuff below 20kHz. Even Miska's trusted AKM DAC with his trusted modulator and his trusted Prism analyzer showed that DSD256 is about 3dB noisier than 44.1k PCM, so no more excuse about ADC aliasing and such. If the rise of <20kHz noise is really caused by ADC aliasing, then it simply means DSD256 is still noisier than 44.1k PCM, even in a "Miska approved" environment. Archimago got similar results as well:
Do you need linear power supply for DACs?
The tests were done with the same SoX DSD signal with the same modulator settings, so all differences were originated from the DAC. All RMAA tests were done with the ADI-2 ADC, so with this factor being constant, all differences were originated from the DACs under tests. You just don't seem...
Regardless of audibility, the whole DSD upsampling thing is simply a waste of time.
Good point! Here's ADI-2 Pro FS, DSD256 (blue) vs PCM192 (red). Captured by Cosmos ADC @ 192k.
By the way, both, DSD and PCM playing through HQPlayer
Same, but zoomed out
Last edited:
Yes, that looks about right.
The DR spec for AKM DAC in ADI-2 is about 3dB worse in DSD mode.
The Cosmos ADC (used for measurement) is really good. One of the very few ADC's to have very flat noise floor up to 100kHz -> great for
WB measurements.
TCD
Higher sample rates (and bit depth in the case of PCM) must have a potential to achieve lower noise floor in digital domain, that's for sure. So "DSD256 is still noisier than 44.1k PCM" is a comment to Miska's measurements in analog domain. If you have to interpret my previous post in the way you think, then it is really up to you.
I'd say the 3dB difference in analog domain is probably the RME DAC. If he was using Prism H/W I'd be looking at that. Very unlikely to be HQplayer.
TCD
Analogue output levels the same ?Good point! Here's ADI-2 Pro FS, DSD256 (blue) vs PCM192 (red). Captured by Cosmos ADC @ 192k.
By the way, both, DSD and PCM playing through HQPlayer
View attachment 196716
Same, but zoomed out
View attachment 196722
In Vrms
Yes, the same. In fact, that's why I posted the zoomed out version to show that PCM output was at the same level at 0dBc as it was with DSD.
Is that measuring Vrms of the analogue outputs?
Input signal might be 0dBFS for both, but that's seperate to output level?
And is that ADI-2 in "DSD direct" mode?
It's the output level, as measured by the ADC. The plots I posted show only the signal recorded by the ADC. How could it be a separate output level?
And yes, DSD Direct = ON
Well, that settles that now doesn't it...
Similar threads
