Measurements of the Fiio E10k Line Out

[Thalis]

I got a new MM that can measure low VAC and frequencies so I was very eager to take it on a test run and measure the Line Out of the Fiio E10k. As expected Low or High gain had no effect on the output. But here's where it was a little weird for me. At various frequencies, I get different measurements.

Using Foobar2000 to generate the tones @16bit 44.1kHz @0dB and sending bitperfect to the DAC (WASAPI).

I will list out some (all left channel - I found right channel to be the same) :

10Hz 0.006VAC
20Hz 0.015VAC
50Hz 0.045VAC
60Hz 0.054VAC

100Hz 0.094VAC
200Hz 0.192VAC
400Hz 0.384VAC
600Hz 0.567VAC

1kHz 0.880VAC
3kHz 1.611VAC
4kHz 1.672VAC
5kHz 1.675VAC
7kHz 1.633VAC

10kHz 1.570VAC
11kHz 1.554VAC
15kHz 1.507VAC
17kHz 1.491VAC
18kHz 1.484VAC
19kHz 1.478VAC
20kHz 1.471VAC

I did not expect such margin but I don't know how it relates to the DAC's actual performance. I most definitely did not expect 1kHz to be that low and expected it to be at least 1.5VAC if not nearer to 2VAC. But looking at the higher frequencies it does seem to be within specs? So if I were to make sure my USB mixer (variable output) has a 2VAC output, do I just measure its higher frequencies to try to get close to 2VAC or do I use 1kHz and set it to 2VAC?

Hope to get some feedback.... thank you.

 

[solderdude]

Doesn't make sense.
Did the amplitude look the same on the 'scope' part ?
Maybe you have the time-base set incorrectly on the 'scope section'.
I would have expected better resolution but maybe it is due to the time-base.
The meter 'measures' using the scope part most likely.
One should at least see 3 full waves on the screen before it can calculate the voltage.

 

[Thalis]

Doesn't make sense.
Did the amplitude look the same on the 'scope' part ?
Maybe you have the time-base set incorrectly on the 'scope section'.
I would have expected better resolution but maybe it is due to the time-base.
The meter 'measures' using the scope part most likely.
One should at least see 3 full waves on the screen before it can calculate the voltage.

1. Pressing the display on MM to display the amplitude it did rise to 0.999 kHz for the 1kHz tone
2. Ok not sure about "time base". Can you explain a bit more?
3. 3 full waves as in 3 peaks and 3 dips?

Edit... always willing to retest and learn how to use the new MM

 

[solderdude]

When measuring AC you should always see at least 2 full sine-waves on the scope screen.
I assume the scope section has the ability to set the time (or the auto function) so that one sees the waveform on the screen.
You may have to set it again for each frequency.
https://www.manualslib.com/manual/1480398/Mustool-Mt8206.html?page=29#manual

3. 3 full waves as in 3 peaks and 3 dips?

Yes, at least 2 or 3 for each frequency.

 

[Thalis]

Testing 1kHz tone..........

I managed to get screen to display 3 full waveforms. I can also make it display 1, 2, 3, 6 etc full waves.... but the voltage remains the same at 0.880VAC

Edit... also trying 10kHz... showing 3 full waves.... 1.570VAC

 

[solderdude]

As long as it has at least 1 complete (better = 2) it should display the correct voltage. I assume RMS is calculated.

For those wondering what this is all about: Mustool MT8206 multimeter with waveform display.

 

[Thalis]

Hopefully I am just doing it wrong

 

[Thalis]

Well... @100Hz the graph can't even display properly but the voltage remains as I have listed

 

[Thalis]

Is the E10k is rated at 1.5VAC output or was it supposed to be 2VAC?

 

[Thalis]

Here is the MM display @3kHz

 

[Thalis]

@solderdude

After re-reading the manual several times... the Tip for waveform of Voltage Measurements says this:

The DC voltage file DCmV/V) uses a large time base scan method to select the appropriate time base to capture the waveform when measuring the waveform ACmV small signal waveform, you need to manually enter the ACmV range, then press the "SELE" button to enter the waveform display.

so I have to press REL and SELE to change the time base. What should I enter?

 

[Thalis]

ah I understand now.... I need to be in waveform display in order to change the time base... I can use REL and SELE (up and down) to change the time base and have how many full waves i want to see.

So I have been doing that but unfortunately the VAC still remains approx the same as I have measured earlier

 

[solderdude]

It makes no sense that the meter would not be accurate at 50Hz for instance.
1.5V AC should not register as 0.015V 0.045V

 

[Thalis]

It makes no sense that the meter would not be accurate at 50Hz for instance.
1.5V AC should not register as 0.015V

I actually listed 50Hz at 0.045 VAC. However... I watched some videos on the MM and the reviewer did say this is RMS. Not sure how to calculate that back into just VAC.

 

[solderdude]

RMS is 0.707xVp for a pure sinewave. For a sinewave RMS is what the VAC setting should show.
Measure the mains for instance. See if that is correct.

1.5V (if it is really there) should measure as 1.5V not 0.045V no need to calculate anything.

Maybe use an online tone generator ?

 

[Thalis]

RMS is 0.707xVp for a pure sinewave. For a sinewave RMS is what the VAC setting should show.
Measure the mains for instance. See if that is correct.

1.5V (if it is really there) should measure as 1.5V not 0.045V no need to calculate anything.

Maybe use an online tone generator ?

Checked mains earlier......... getting 237.2VAC @50.003Hz. So its working as it should.

Which online tone generator would you recommend?

 

[solderdude]

https://www.szynalski.com/tone-generator/

https://onlinetonegenerator.com/ (you can even look at waveforms !)

https://www.gieson.com/Library/projects/utilities/tonegen/

https://www.wavtones.com/functiongenerator.php

 

[Thalis]

@solderdude

I don't know what the hell I did.... tried measuring the E30 and initially getting disappointed. Then suddenly the MM "came alive" even though I wasn't probing the ground sleeve of the RCA. The MM started showing 2.1VAC at 1kHz, 50Hz, 20Hz and 15kHz.

Without turning the MM off.......... I started probing the Fiio E10k again and i am getting:

10Hz 1.457VAC
20Hz 1.466VAC
50Hz 1.469VAC
60Hz 1.469VAC

100Hz 1.470VAC
200Hz 1.470VAC

1kHz 1.467VAC
3kHz 1.465VAC
4kHz 1.465VAC

10kHz 1.458VAC
15kHz 1.449VAC
20kHz 1.437VAC

I still have no idea what the hell i did!

 

[solderdude]

Looks good.
It's always frustrating when you have no idea why something didn't work directly.
Maybe the probe ?

Set it to resistance, connect the probes and wiggle, pull etc on the probes to check if the probes are O.K.

 

[Thalis]

Spoke too soon... was setting up my USB mixer to 2VAC output and doing fine from 10Hz to 1kHz then I turned the knob to frequency and back to VAC and its giving me rubbish reading again