Your screenshot shows digital generator output as OFF, so at least for what you posted I don’t see how you were sending a signal to the DAC.
If you were actually sending a 0 dBFS sine to analog input of the AP the peak monitor levels would be higher than -30 dBu.
Michael
We tested it on and off. I have the (on) screenshot also however they show the same measurements. No difference if the digital signal was on or off. We even muted the digital signal in and no change was noted.
Can you please share the screenshot with the digital generator on?
Michael
As I stated above it’s the same.
If that is the case I would like to see it because something in your measurement setup is incorrect.
Again, please explain how your peak monitor levels are showing -30 dBu when you are sending a 0 dBFS sine? If that is what it shows with your digital generator ON you are not getting the appropriate signal to the AP.
Michael
We will be doing new testing in the near future when we get time. No matter what settings / signals we tested with the numbers I posted never showed flavorful results better than what was posted.
I think you should do your own measurements the way you would like.
BTW We did the testing the exact same for the MK1 and the MK2.
Why not just post them?
If they are correct this will be apparent. If not, we learn something.
My son has them and is not available.
We will be posting complete measurements including FFT on the other forum.
Here:
https://forum.audiogon.com/discussions/modding-the-ps-audio-directstream-dac-mk1-and-mk2?lastpage=true&page=3
Where are PS Audio measurements?
I think they should post them here as promised by Paul several months ago.
We look forward to seeing them.
We do also.
We all would also like PS Audio measurements.
@mdsimon2 if you have specific requests in measuring let us know. We will try and include them.
From May 15.
Awesome, thanks!
I’d like to see a test where you (or @Paul!) send a -60 dBFS 1 kHz sine from the digital generator to each DAC and then measure THD+N with a 22 Hz high pass and a 20 kHz low pass. From this we can determine dynamic range for each DAC. If you note the 0 dBFS output level for each DAC we can also calculate residual noise.
I’d also love to see a FFT of both DACs at the same output level. I like 2 mV for noise measurements as it is usually pretty close to -60 dBFS.
Here are some examples from DACs I’ve measured. Unfortunately I am not using an AP but consumer ADCs and REW are so good these days you can get amazing results with minimal investment.
DAC 1
0 dBFS = 1.23 V
dynamic range = 51.6 + 60 = 111.6 dB
residual noise = 1.23 x 10^(-111.6/20) x 10^6 = 3.2 uV
DAC 2
0 dBFS = 4.40 V
dynamic range = 61.9 + 60 = 121.9 dB
residual noise = 4.4 x 10^(-121.9/20) x 10^6 = 3.5 uV
DAC 3
0 dBFS = 3.83 V
dynamic range = 42.6 + 60 = 102.6 dB
residual noise = 3.83 x 10^(-102.6/20) x 10^6 = 28.4 uV
Both DAC 1 and 2 are very low noise. DAC 1 has a slightly lower absolute noise level than DAC 2 but DAC 2 has higher dynamic range because of the higher output level at 0 dBFS. Either of these DACs can be used without a preamp with sensitive speakers with no audible hiss. DAC 3 is much higher noise and would be less suited for use without a preamp.
And finally all three DACs compared at 2 mV output level on a common FFT. Here it is very easy to see that DACs 1 and 2 have very low and similar absolute noise levels, while DAC 3 clearly has much higher noise.
Michael
Great stuff, Michael
We are only doing the MK2. One DAC.
In the past we used an RME ADI-2 PRO FS R and REW however it was not a perfect measurement solution. Our AP is calibrated and industry standard. PS Audio uses it as well as most other manufacturers.
AP we use to automate our transformers measurements and testing.
Compiled list from the locked down and closed topic “Firmware updates and fixes for the new Directstream MK2.”
* web interface to control settings.* NOT WORKING ON.
**Added #16 8/14/23
It seems #8 has already been done in the new Massive firmware
#5,6,10,11,14, and 15 are corrected now.
All others have not been verified or documented.
As I recall the fix for ticks and pops , #7, was to mute the output between tracks and ramp up the volume quickly when a track begins. (This was for the Mk1 and I probably also the Mk2 ?) For some of the Mk1 code updates some users reported having music dropouts at beginning or end of tracks and it was eventually fixed. I never had this problem until Massive.
I use PST to DS exclusively and now have two disks with beginning of track cut off. I have had every PSA transport and DAC they have made and these two disks played fine, including with Antero.
Unless I am mistaken about the mute/volume ramp up it seems #7 is not fixed, or at least not without creating another problem.
OK… I removed #7 from the list of corrected issues. I also noticed a slight cut-off of songs on the latest update. Perhaps it’s a little aggressive now.