Does it help if I do D10S, E30, D70s, D90, M400?
It would be great if you also have KTB. So I could see if the trends I observed is similar to your measurements. But, I am still very curious about all the devices you mentioned. Yes, it will help answer my curiosity a lot!Does it help if I do D10S, E30, D70s, D90, M400?
Thanks for doing the measurements. I really appreciate it! However, this did not answer my curiosity, unfortunately.Most of the difference should be caused by the noise fluctuating. And that was shown in the range of +-1db
If we put them all in the same graph and use the usual +-5db range we get thisView attachment 111206
Basically nothing to worry about and certainly nothing is going on around -20dB to 0dB at least with these devices.
One thing to think about is that DACs really just care about voltage level at a point. If there is a issue in this test there is a very large chance the distortion performance would be horrible. So in different ways, they inter-assured each other.
Some times when DACs do some weird thing like class G or power saving things there may be something showing up around -20dB but in music context it's almost a non-issue as music is dynamic.
If you think about it, linearity test covers what you want.Thanks for doing the measurements. I really appreciate it! However, this did not answer my curiosity, unfortunately.
What I am asking for is different.
All DAC should be at max dB.
All DAC fed -16 dB.
Then, check voltage output of all DAC when being fed multiple frequencies at -16db.
Can you show me when being fed -16, DAC at 0 dB or DAC mode), what is the actual measured output in voltage for each frequency (you measured 4, this is still good), for each DAC (btw, using what filter by default?)?
Again, thank you for helping!
I really appreciate it. Thanks!If you think about it, linearity test covers what you want.
However I can do frequency response at -16dB if you wish. But it's pretty straightforward that you won't see anything. Well, I'll do some anyway.
Excellent!View attachment 111268
All fed with -16dB signal.
They are outputting different level because the 0dB output level is a bit different for each dac.Excellent!
Interestingly, all output at different level when fed same signals. At its respective level, all devices are pretty much flat until +10 kHz for one DAC.
Do you see anything to worry about at all? The bottom 2 looks different in term of flatness. Thank you very much!
Indeed, KTB, E30, and X16 measured similar at sub bass levels using my multimeter.They are outputting different level because the 0dB output level is a bit different for each dac.
The roll off is probably due to digital filter or something. It's still mild roll off in dB sense.
I didn't see anything else to worry about at all as already demonstrated much more deeply by the linearity test.
So basically it should be the high frequency modulation noise messed up the multimeter. It's usually not an accurate instrument at higher frequencies than 100Hz.
Would you please confirm my understanding? In your graph, from top line to bottom line, the DAC are as follows?View attachment 111268
All fed with -16dB signal.
The one with rolled off high was E30 with F-2 filter. With proper filter 1,3,6 you don't get the roll off. Default is the F-3.Would you please confirm my understanding? In your graph, from top line to bottom line, the DAC are as follows?
D10s
D70s
D90
E30
M400
Or in different order from top to bottom?
Thanks!
Good to know. Based on your measurements, it would confirm that my meter, although not accurate, could show a trend. My measurements also show a roll off from ~3Kh for filter 5, as compared to other filters, just like yours.The one with rolled off high was E30 with F-2 filter. With proper filter 1,3,6 you don't get the roll off. Default is the F-3.View attachment 111271
BTW, you confirmed that in your 5 DAC measurements chart, the one with slope is E30. What about the rest? Would you please confirm if this order is correct, from top line to bottom line in your chart?The one with rolled off high was E30 with F-2 filter. With proper filter 1,3,6 you don't get the roll off. Default is the F-3.View attachment 111271
Hmm, if the one with curve is e30, when provided -16 signals, it only outputs about 350mV? Strange. This is via USB input?View attachment 111268
All fed with -16dB signal.
Your REW was probably accounting for another 3dB in there. Hence your -16db = my -13db. 479*0.707=338 close enough.Hmm, if the one with curve is e30, when provided -16 signals, it only outputs about 350mV? Stange. This is via USB input?
My test shows 479mV. USB in from laptop, using REW to generate tones at -16db.
I see. Yes, I believe I noticed a -3db in one setting that I couldn't changed to 0db.Your REW was probably accounting for another 3dB in there. Hence your -16db = my -13db. 479*0.707=338 close enough.
I guess there is no international standard regarding how DAC should react to a certain signals?View attachment 111268
All fed with -16dB signal.
Firstly the output voltage is indeed non-standardised. The convention for modern days is 2V or so for unbalanced output and 4V for balanced output. For traditional home uses and studio uses there can be vast differences.I guess there is no international standard regarding how DAC should react to a certain signals?
It would seems two of the top line DAC would output more than twice the voltage than the bottom line DAC, when being fed same -16db signals.