Here is a review and measurements of the
The #9039S is VERY small, as you may see on the pictures, where it's laying on my Samsung S23 Ultra.
And it weights a mere 12g.
I received it for free from Ivan (Mr E1DA, aka @IVX) for measurements in 2024.
But only now, with the new AudioPrecision APx 500 Flex 10.0 software, I can run all our usual tests, since it allows different device drivers for output and input.
I see it announced at prices ranging from 122€ to 170€ here in Europe.
Is it worth the money ?
First an important note:
This is a BALANCED ONLY DAC/amp.
DO NOT connect an unbalanced headphones or load to it or you may break it !
It comes with a USB C port and a 2.5mm Balanced output connector.
The only form of feedback is coming with a small white led next to the USB connector.
Technically, E1DA tells us it's based on an ESS ES9039Q2M chip and uses OPA1612 and AD8397 high quality OpAmps.
RME ADI-2/4 Pro SE, as the main ADC.
For very low levels, I used the RME 12Mic-D Mic preamp/interface or the RME UFX III interface.
To get the last bit of performance for SINAD measurement, I also used the E1DA APU with notch filter.
For this review, I used Audio Precision APx 500 Flex 10.0, where possible.
Some measurements were done with my ususal software, Virtins Multi Instrument (now version 3.9.16).
There are some limitations and differences compared to Amir's testing with an Audio Precision APx555.
That's more than enough to get a good idea of the device performances though.
I'll post comments where such differences are most important.
Conditions are therefore not exactly the same, so please don't compare this directly to Amir's figures.
Any value approaching or above 120dB SINAD should be considered state of the art anyway.
For this measurement, I used the APx 500 Flex software, with the RME ADI-2/4 Pro SE and an external E1DA APU notch filter.
I can only measure one channel at a time, This is left channel. Right channel is similar.
Now that is something from such a tiny device, isn't it ?
All distortion peaks are below -140dB !
We don't reach 4V: max level is 3.5Vrms.
Important: this is A-Weighted, to compare with E1DA specs.
I re-measured with all 3 usual weighting and got following (slightly better) results :
I don't have an explanation for low frequencies.
It's more than good enough, anyway.
(balanced) output
It matches the announced <0.1 Ohm at 1kHz.
Measured with a calibrated Brymen BM869s
Compared with the Topping D50 III, which uses 2 of the same DAC chip, we get equal or better performance, which is impressive.
Here we have real measurements. (997Hz, 200k ohm load, both channels averaged)
But, as usual when there is no analog attenuator, SNR at 50mV could have been deducted/computed from Dynamic range with reasonable accuracy.
That would land it around here in the ranking of all Headphones amplifiers tested:
I didn't use the E1DA APU notch to measure this, so we don't reach the same SINAD level, but that's limited by the ADC, not by the DAC.
This is incredible performance from such a small DAC !
Impedance has no impact until 16 ohm.
And with 12 ohm, it still pushes >2.6Vrms.
All figures here-above are reached with SINAD >118dB !
I didn't reach the spec for 12 and 16 Ohm.
(Maybe because it's very hot here today: Temperature in my room is 34.5°C right now !)
The difference is less than 1dB though, so negligible...
Power profile is clearly oriented towards low impedance headphones.
With my insensitive Dan Clark E3, I can get more than enough SPL for my taste - and I like it loud !
Amir measured the E3 as 27 ohm and he says 512mV were required to get 94dB SPL - so we should get around 110dB SPL without added distortion from the #9039S.
Note that, the #9039S gets quite hot:
I measured around 47°C on the surface after my (admitedly very tough) tests.
How to say ?
Granted, it's a sample (possibly) cherry picked by Ivan for measurements.
By the way, he was quite frustrated, because he thinks I could get better measurements still.
(Archimago was able to get even better figures - so I think Ivan is right...)
But is it worth it, anyway ?
What we have here is plenty enough to demonstrate the device's capability.
This is more than excellent !
This is better than good - it's world class for such a tiny devices.
And even if a random sample gets 1dB lesser figures (?), it still measures way better than anything on the market in that category to date.
E1DA #9039S balanced USB DAC and Headphones amplifier
The #9039S is VERY small, as you may see on the pictures, where it's laying on my Samsung S23 Ultra.
And it weights a mere 12g.
I received it for free from Ivan (Mr E1DA, aka @IVX) for measurements in 2024.
But only now, with the new AudioPrecision APx 500 Flex 10.0 software, I can run all our usual tests, since it allows different device drivers for output and input.
I see it announced at prices ranging from 122€ to 170€ here in Europe.
Is it worth the money ?
First an important note:
This is a BALANCED ONLY DAC/amp.
DO NOT connect an unbalanced headphones or load to it or you may break it !
It comes with a USB C port and a 2.5mm Balanced output connector.
The only form of feedback is coming with a small white led next to the USB connector.
Technically, E1DA tells us it's based on an ESS ES9039Q2M chip and uses OPA1612 and AD8397 high quality OpAmps.
Measurements
Measures are performed with following equipment:RME ADI-2/4 Pro SE, as the main ADC.
For very low levels, I used the RME 12Mic-D Mic preamp/interface or the RME UFX III interface.
To get the last bit of performance for SINAD measurement, I also used the E1DA APU with notch filter.
For this review, I used Audio Precision APx 500 Flex 10.0, where possible.
Some measurements were done with my ususal software, Virtins Multi Instrument (now version 3.9.16).
There are some limitations and differences compared to Amir's testing with an Audio Precision APx555.
That's more than enough to get a good idea of the device performances though.
I'll post comments where such differences are most important.
SINAD measurement
NB: I don't own an Audio Precision analyzer.Conditions are therefore not exactly the same, so please don't compare this directly to Amir's figures.
Any value approaching or above 120dB SINAD should be considered state of the art anyway.
For this measurement, I used the APx 500 Flex software, with the RME ADI-2/4 Pro SE and an external E1DA APU notch filter.
I can only measure one channel at a time, This is left channel. Right channel is similar.
Now that is something from such a tiny device, isn't it ?
All distortion peaks are below -140dB !
We don't reach 4V: max level is 3.5Vrms.
Dynamic range
Important: this is A-Weighted, to compare with E1DA specs.
I re-measured with all 3 usual weighting and got following (slightly better) results :
Linearity
Multitone
I don't have an explanation for low frequencies.
It's more than good enough, anyway.
Output impedance
(balanced) output
| Open circuit Voltage (-3dBFS) | V1 | 2,486 | Vrms |
| Load resistance | RL | 12,3 | Ohm |
| Loaded circuit Voltage | V2 | 2,470 | Vrms |
| Zo=RL*(V1/V2-1) | Zo | 0,08 | Ohm |
It matches the announced <0.1 Ohm at 1kHz.
Measured with a calibrated Brymen BM869s
IMD+N measurement
Compared with the Topping D50 III, which uses 2 of the same DAC chip, we get equal or better performance, which is impressive.
Jitter
Filter performance
Headphones amplifier
Signal to Noise Ratio at 50mV
Here we have real measurements. (997Hz, 200k ohm load, both channels averaged)
But, as usual when there is no analog attenuator, SNR at 50mV could have been deducted/computed from Dynamic range with reasonable accuracy.
That would land it around here in the ranking of all Headphones amplifiers tested:
Voltage vs Impedance
I didn't use the E1DA APU notch to measure this, so we don't reach the same SINAD level, but that's limited by the ADC, not by the DAC.
This is incredible performance from such a small DAC !
Impedance has no impact until 16 ohm.
And with 12 ohm, it still pushes >2.6Vrms.
All figures here-above are reached with SINAD >118dB !
I didn't reach the spec for 12 and 16 Ohm.
(Maybe because it's very hot here today: Temperature in my room is 34.5°C right now !)
The difference is less than 1dB though, so negligible...
Power profile is clearly oriented towards low impedance headphones.
With my insensitive Dan Clark E3, I can get more than enough SPL for my taste - and I like it loud !
Amir measured the E3 as 27 ohm and he says 512mV were required to get 94dB SPL - so we should get around 110dB SPL without added distortion from the #9039S.
Note that, the #9039S gets quite hot:
I measured around 47°C on the surface after my (admitedly very tough) tests.
Conclusion
How to say ?
Granted, it's a sample (possibly) cherry picked by Ivan for measurements.
By the way, he was quite frustrated, because he thinks I could get better measurements still.
(Archimago was able to get even better figures - so I think Ivan is right...)
But is it worth it, anyway ?
What we have here is plenty enough to demonstrate the device's capability.
This is more than excellent !
This is better than good - it's world class for such a tiny devices.
And even if a random sample gets 1dB lesser figures (?), it still measures way better than anything on the market in that category to date.
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