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E1DA 9038D Review (portable DAC & Amp)

amirm

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#1
This is a review and detailed measurements of the E1DA 9038D portable DAC and headphone dongle (US $99). It was kindly sent to me the company and forum member, @IVX. Sadly it has been sitting here for months until I got a chance to review it now. If you don't know about @IVX, he was the first one to break the laws of physics and produce a high power headphone dongle using balanced output. Seeing how he was self-thought in designing this dongle, it was a remarkable thing. But not everyone has a headphone with balanced wiring so here comes the 9038D in unbalanced configuration:

E1DA 9038D review dac and portable headphone amplifier.jpg


Connectivity is as you can expect with USB-C and 3.5mm jack:
E1DA 9038D review dac and portable headphone amplifier USB-C dongle.jpg


I was very thankful to have a driver for the 9038D. Without it, the class driver in Windows exposes a 16 bit interface to my audio analyzer interface causing artifacts. As such, I usually run a subset of my tests with these dongles. In this case, I did manage to run all of my tests. I did run into an issue though which I don't know if it has to do with the driver or not. If I pause music in my Roon player, after 15 seconds or so, the device seems to power down as I hear some clicking and then low level static as if a capacitor is draining. It does recover when you hit play again so not a major inconvenience but it is there.

There is a second problem in that full amplitude digital signal causes mild clipping of samples. I saw that company specs it at -0.5 dB so I am assuming designer is aware of this issue.

E1DA 9038D Measurements (DAC)
Treating the device as a straight DAC, I ran my normal suite of tests:

E1DA 9038D Measurements DAC Headphone Amp.png


Note again that I am testing at -.05 dBFS. At full amplitude performance drops to 88 dB or so. At 0.5 dBFS, performance is excellent for any DAC, let alone a small one:
best headphone dongle review.png


Output level is 2.7 volts which means we will have good power to drive high impedance headphones.

Dynamic range at full output is excellent for a dongle and a bit above average at 50 mv output:

E1DA 9038D Measurements DAC Dynamic Range Headphone Amp.png


best USB dongle noise review.png


DAC reconstruction filter performance is an exception in a good way:
E1DA 9038D Measurements DAC Filter Headphone Amp.png


It is one of a handful of DACs that has a sharp enough filter to properly cut off out of band "images." I wonder though if this sharp filter has enough overshoot to cause the clipping we see at 0 dBFS.

Sweeping for output voltage we see the clipping point:
E1DA 9038D Measurements THD+N vs Level DAC Headphone Amp.png


IMD test shows excellent performance with essentially no sign of "ESS IMD hump:"

E1DA 9038D Measurements IMD DAC Headphone Amp.png


Linearity was superb showing high accuracy:
E1DA 9038D Measurements DAC Linearity Headphone Amp.png


Jitter test shows fair bit of unwanted tones but that is because the noise floor is very low. What is there is definitely not audible:

E1DA 9038D Measurements Jitter DAC Headphone Amp.png


Multitone performance is superb:
E1DA 9038D Measurements Multitone DAC Headphone Amp.png


As a side thing, people keep thinking that my tests are "simple" sine wave and that music waveforms are more complex. Here is the time domain (i.e. what the samples look like) of the multitone signal:
Multitone waveform.png


Doesn't look simple to me. Does it to you?

E1DA 9038D Measurements (Headphone Amp)
Power is everything in headphone amps so let's see how much we have at 300 ohm:
E1DA 9038D Measurements DAC Power into 300 ohm Headphone Amp.png


Compared to $9 dongles, this is a lot of power:
best portable headphone amplifier 300 ohm.png


Balanced devices though beat it because they can go up to 4 volts output. Tables get turned though when we use a low impedance load and rely on current delivery:

best portable headphone amplifier 33 ohm.png


E1DA 9038D Listening Tests
I used my usual Ether CX and Sennheiser HD-650 headphones (low and high impedance respectively). Performance was excellent with both. I was able to go to max power and get plenty of volume with no sign of distortion. Detail, bass performance, etc. was all up there. You can't go deaf using this dongle so desktop products produce even more power but what is here is plenty for on-the-go usage.

Conclusions
Given the pedigree of 9038D, I expected excellent performance and that is what I got. Two functionality bugs with 0 dBFS clipping and power down kept me from giving it the highest honors. I am hoping one is driver issue and/or is resolved by now.

As is, I am happy to give a recommendation to E1DA 9038D.

------------
As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 

Matias

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#4
Why measured and ranked in 2.7 Vrms and not the "ASR standard" 2.0 Vrms?
 

Jimbob54

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#6
This is a review and detailed measurements of the E1DA 9038D portable DAC and headphone dongle (US $99). It was kindly sent to me the company and forum member, @IVX. Sadly it has been sitting here for months until I got a chance to review it now. If you don't know about @IVX, he was the first one to break the laws of physics and produce a high power headphone dongle using balanced output. Seeing how he was self-thought in designing this dongle, it was a remarkable thing. But not everyone has a headphone with balanced wiring so here comes the 9038D in unbalanced configuration:

View attachment 119188

Connectivity is as you can expect with USB-C and 3.5mm jack:
View attachment 119189

I was very thankful to have a driver for the 9038D. Without it, the class driver in Windows exposes a 16 bit interface to my audio analyzer interface causing artifacts. As such, I usually run a subset of my tests with these dongles. In this case, I did manage to run all of my tests. I did run into an issue though which I don't know if it has to do with the driver or not. If I pause music in my Roon player, after 15 seconds or so, the device seems to power down as I hear some clicking and then low level static as if a capacitor is draining. It does recover when you hit play again so not a major inconvenience but it is there.

There is a second problem in that full amplitude digital signal causes mild clipping of samples. I saw that company specs it at -0.5 dB so I am assuming designer is aware of this issue.

E1DA 9038D Measurements (DAC)
Treating the device as a straight DAC, I ran my normal suite of tests:

View attachment 119190

Note again that I am testing at -.05 dBFS. At full amplitude performance drops to 88 dB or so. At 0.5 dBFS, performance is excellent for any DAC, let alone a small one:
View attachment 119191

Output level is 2.7 volts which means we will have good power to drive high impedance headphones.

Dynamic range at full output is excellent for a dongle and a bit above average at 50 mv output:

View attachment 119192

View attachment 119194

DAC reconstruction filter performance is an exception in a good way:
View attachment 119197

It is one of a handful of DACs that has a sharp enough filter to properly cut off out of band "images." I wonder though if this sharp filter has enough overshoot to cause the clipping we see at 0 dBFS.

Sweeping for output voltage we see the clipping point:
View attachment 119198

IMD test shows excellent performance with essentially no sign of "ESS IMD hump:"

View attachment 119199

Linearity was superb showing high accuracy:
View attachment 119200

Jitter test shows fair bit of unwanted tones but that is because the noise floor is very low. What is there is definitely not audible:

View attachment 119201

Multitone performance is superb:
View attachment 119202

As a side thing, people keep thinking that my tests are "simple" sine wave and that music waveforms are more complex. Here is the time domain (i.e. what the samples look like) of the multitone signal:
View attachment 119203

Doesn't look simple to me. Does it to you?

E1DA 9038D Measurements (Headphone Amp)
Power is everything in headphone amps so let's see how much we have at 300 ohm:
View attachment 119204

Compared to $9 dongles, this is a lot of power:
View attachment 119205

Balanced devices though beat it because they can go up to 4 volts output. Tables get turned though when we use a low impedance load and rely on current delivery:

View attachment 119206

E1DA 9038D Listening Tests
I used my usual Ether CX and Sennheiser HD-650 headphones (low and high impedance respectively). Performance was excellent with both. I was able to go to max power and get plenty of volume with no sign of distortion. Detail, bass performance, etc. was all up there. You can't go deaf using this dongle so desktop products produce even more power but what is here is plenty for on-the-go usage.

Conclusions
Given the pedigree of 9038D, I expected excellent performance and that is what I got. Two functionality bugs with 0 dBFS clipping and power down kept me from giving it the highest honors. I am hoping one is driver issue and/or is resolved by now.

As is, I am happy to give a recommendation to E1DA 9038D.

------------
As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Outstanding @IVX . Glad to own one.
 

Jimbob54

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#8
Why measured and ranked in 2.7 Vrms and not the "ASR standard" 2.0 Vrms?
Good point. Nice to know it performs well at this level but yes, 2V output also would be nice to see.
 

Matias

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#9
Good point. Nice to know it performs well at this level but yes, 2V output also would be nice to see.
It is there in the voltage versus SINAD graph, 1 dB less SINAD or so, but still it was strange seeing the dashboard out of ASR standards. Or maybe I am just nit picking and must drink more alcohol. :)
 

Jimbob54

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#10
It is there in the voltage versus SINAD graph, 1 dB less SINAD or so, but still it was strange seeing the dashboard out of ASR standards. Or maybe I am just nit picking and must drink more alcohol. :)
I have drunk more and didn't see it. So no, let's both retire from this thread before showing our arses.
 

staticV3

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#13
For those interested, one of the coolest features is an Android App which controls DAC parameters directly.

The free version can set a hardware volume limiter (e.g. '-27.5dB') for sensitive IEMs or for high sensitivity Amps. It is saved between disconnects and applied no matter what source device you use.
The App can also turn on/off the standby mode that Amir was talking about.
And it can control the 9038D's hardware volume in .5dB steps.

The Pro version costs $10 currently and has a lot of extra features:
  • minimum volume limiter
  • Harmonic Distortion compensation:
    The 9038Q2M chip is able to generate 2nd and 3rd harmonics. This THD compensation can be set in three different zones, depending on the DAC's current hardware volume. All changes happen in real time (see here). With it, you can:
    • increase distortion to simulate your favorite tube amp, or:
    • with the right measurement equipment, introduce phase-inverted harmonics at the same level as the DAC's natural harmonics for a given load, effectively cancelling them out. Here's the result of that:
      Asset_1.png
  • MCLK control:
    You can define the DAC's MCLK for each supported sample rate. Higher MCLK will reduce noise, but will introduce more high-order harmonics.
    Screenshot_20210320-014020_Tweak9038.jpg
  • Reconstruction/Nyquist/Oversampling filter control:
    Similar to the MCLK, for each of the supported sample rates, you can choose between 8 different filters.
    Screenshot_20210320-014355_Tweak9038.jpg
  • Presets:
    You can save all your settings as presets, share them with others, as well as choose from a number of official presets.
All changes you make in the App happen in real-time, and can be done while playing music, which makes choosing a filter for example a lot easier.
An iOS version is impossible due to Apple's USB restrictions.
The App is called Tweak9038.
 
Last edited:

Vini darko

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#14
For those interested, one of the coolest features is an Android App which controls DAC parameters directly.

The free version can set a hardware volume limiter (e.g. '-27.5dB') for sensitive IEMs or for high sensitivity Amps. It is saved between disconnects and applied no matter what source device you use.
The App can also turn on/off the standby mode that Amir was talking about.
And it can control the 9038D's hardware volume in .5dB steps.

The Pro version costs $10 currently and has a lot of extra features:
  • minimum volume limiter
  • Harmonic Distortion compensation:
    The 9038Q2M chip is able to generate 2nd and 3rd harmonics. This THD compensation can be set in three different zones, depending on the DAC's current hardware volume. All changes happen in real time (see here). With it, you can:
    • increase distortion to simulate your favorite tube amp, or:
    • with the right measurement equipment, introduce phase-inverted harmonics at the same level of the DAC's natural harmonics for a given load, effectively cancelling them out. Here's the result of that:
      View attachment 119214
  • MCLK control:
    You can define the DAC's MCLK for each supported sample rate. Higfher MCLK will reduce noise, but will introduce more high-order harmonics.
    View attachment 119215
  • Reconstruction/Nyquist/Oversampling filter control:
    Similar to the MCLK, for each of the supported sample rates, you can choose between 8 different filters.
    View attachment 119216
  • Presets:
    You can save all your settings as presets, share them with others, as well as choose from a number of official presets.
All changes you make in the App happen in real-time, and can be done while playing music, which makes choosing a filter for example a lot easier.
An iOS version is impossible due to Apple's USB restrictions.
The App is called Tweak9038.
That's a cool list of fuctions on a dongle
 

Tks

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#16
Pretty nice, though I'm surprised there's regressions in the 50mV spec and also the odd channel balance being a bit off (would have imagined this wouldn't be a thing).

I also appreciate the SINAD stability throughout the power range when usually you see lower levels on other DACs perfoming far worse than max output. Peak power is also massive (a single ended dongle pulling through beyond 2V spec is really something to behold).

Btw @amirm did you measure THD+N Ratio vs Frequency, or thermal metrics since this thing will be in all sorts of environmental settings I imagine?
 
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#17
If I pause music in my Roon player, after 15 seconds or so, the device seems to power down as I hear some clicking and then low level static as if a capacitor is draining.
Check in the Device Manager under USB devices to see if any of the root hub devices or other attached USB devices has a Power Management tab under its properties. If it does, there should be a 'Enable selective suspend' checkbox there. Uncheck it.
 

MC_RME

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#19
That is exactly what I need. Max output level +9.3 dBu even at 33 Ohms load. 7 dB more oomph compared to US iPhones, more than 10 dB compared to castrated EU iphones. Which throws up the question: how do I use it with an iPhone and its Lightning connector? And if there is a matching cable, will there be enough current available? iPhones 11 Pro owner here.
 
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#20
That is exactly what I need. Max output level +9.3 dBu even at 33 Ohms load. 7 dB more oomph compared to US iPhones, more than 10 dB compared to castrated EU iphones. Which throws up the question: how do I use it with an iPhone and its Lightning connector? And if there is a matching cable, will there be enough current available? iPhones 11 Pro owner here.
You'd need something like this. However, the iPhone may not be able to supply the required current to power the device. You'd have to test it yourself for suitability for your needs.
 

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