E1DA 9038D Review (portable DAC & Amp)

[staticV3]

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.

Getting current out of an iPhone to power accessories is a tricky business.
Having an MFI chip either inside the cable, or inside the DAC is a must.
Different cables will have differently configued MFI chips inside, unlocking different amounts of current from an iPhone.
Different iPhones will unlock different amounts of current, even with the same MFI cable and chip.

Updating the 9038D's firmware to version 'Tweak_9038D_C.hex' is recommended. In this firmware, one of the USB descriptors of the DAC is set to "self-powered" instead of "USB bus-powered". The iPhone sees this and pays less attention to the current draw.
Using an old firmware may result in a "The connected USB device uses too much power" error message.

All DACs are flashed from the factory with the newest firmware, so if you order now, then it should come with the newest FW already.

Here's a spreadsheet I've created with the help of our Discord community, detailing which MFI cable will work with which iPhone model and which E1DA DAC: https://docs.google.com/spreadsheets/d/1_Yqd7lpt3N2B0kVwzqzHoRmCTO7ZTe32p_xhjuGluh8/edit?usp=sharing

 

[sam_adams]

This is the MFI chip in the Lightning cable that @staticV3 is talking about:

from here.

 

[Helicopter]

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 of all people, using a CrapIntosh phone. Sad!

 

[vitalii427]

You of all people, using a CrapIntosh phone. Sad!

I feel the same for Android users

 

[Tks]

I feel the same for Android users

I'm somewhere in between. Need some of the Android capabilities and ease of access to app functions that iOS bars. But at the same time Android as an OS in terms of consistency and little things like the keyboard (on the fly auto correct) makes it feel like I'm using an iPhone 3G.. SO BAD.

I just need iOS with the freedom for software development that's fueled by third party app stores - if that were to happen, Android is finished in my view.

 

[IVX]

Amir, as I see your setup has too high common-mode noise or AP analyzer has a problem with its CMRR. I took a look at the result here https://www.audiosciencereview.com/forum/index.php?threads/hidizs-s9-review-headphone-adapter.21152/
The balanced is a lot less noisy vs unbalanced, that's why my balanced 9038S looks so clean vs unbalanced 9038D. You can check that by shorting one of 9038D outputs(of course better if no signal on that channel), I bet you'll find the same dirt on the shorted output as well as on the working one. To avoid that noise you can try to use Android phone in airplane mode and battery-powered with a free Hiby hires player.
My measurement was performed in different ways and always I see the same result +/- a little bit. Regarding Dynamic Range, APx555 has 8x times more noisy inputs vs my custom preamp, hence it is fine if your result up to 1db worse(i.e. 124db(A)) but not 6db of course. The same about THD+N my SYS2522 shows me -117db, SYS2522+external ultra-high performance notch filter(the current 3rd version of that filter has -126db limit for THD+N) 9038D has THD+N -118.3db(-.2-.5dbfs, no-load condition, 20-22000Hz BW 0.00012%). Also, my new project Cosmos ADC(SNR -127db(A) in the mono mode) also shows me THD+N -118db. All my analog processing instruments(120nVrms(A) preamp and notch filter)are well-matched with their preliminary simulation and school physics too(I did test thermal noise of resistors to confirm the noise level resolution).
PS: I want to show how Cosmos ADC sees the signal of 9038D 12kHz@48kHz. No AVG at all. The FFT shows jitter of Cosmos+9038D.

 

[quantum_wave]

Getting current out of an iPhone to power accessories is a tricky business.
Having an MFI chip either inside the cable, or inside the DAC is a must.
Different cables will have differently configued MFI chips inside, unlocking different amounts of current from an iPhone.
Different iPhones will unlock different amounts of current, even with the same MFI cable and chip.

Updating the 9038D's firmware to version 'Tweak_9038D_C.hex' is recommended. In this firmware, one of the USB descriptors of the DAC is set to "self-powered" instead of "USB bus-powered". The iPhone sees this and pays less attention to the current draw.
Using an old firmware may result in a "The connected USB device uses too much power" error message.

All DACs are flashed from the factory with the newest firmware, so if you order now, then it should come with the newest FW already.

Here's a spreadsheet I've created with the help of our Discord community, detailing which MFI cable will work with which iPhone model and which E1DA DAC: https://docs.google.com/spreadsheets/d/1_Yqd7lpt3N2B0kVwzqzHoRmCTO7ZTe32p_xhjuGluh8/edit?usp=sharing

This sheet is awesome. Thanks

 

[vkvedam]

Nice work!

Spotted this, didn't know that Topping's working on a dongle style amp or DAC or a combo

 

[Tks]

Amir, as I see your setup has too high common-mode noise or AP analyzer has a problem with its CMRR. I took a look at the result here https://www.audiosciencereview.com/forum/index.php?threads/hidizs-s9-review-headphone-adapter.21152/
The balanced is a lot less noisy vs unbalanced, that's why my balanced 9038S looks so clean vs unbalanced 9038D. You can check that by shorting one of 9038D outputs(of course better if no signal on that channel), I bet you'll find the same dirt on the shorted output as well as on the working one. To avoid that noise you can try to use Android phone in airplane mode and battery-powered with a free Hiby hires player.
My measurement was performed in different ways and always I see the same result +/- a little bit. Regarding Dynamic Range, APx555 has 8x times more noisy inputs vs my custom preamp, hence it is fine if your result up to 1db worse(i.e. 124db(A)) but not 6db of course. The same about THD+N my SYS2522 shows me -117db, SYS2522+external ultra-high performance notch filter(the current 3rd version of that filter has -126db limit for THD+N) 9038D has THD+N -118.3db(-.2-.5dbfs, no-lad condition, 20-22000Hz BW 0.00012%). Also, my new project Cosmos ADC(SNR -127db(A) in the mono mode) also shows me THD+N -118db. All my analog processing instruments(120nVrms(A) preamp and notch filter)are well-matched with their preliminary simulation and school physics too(I did test thermal noise of resistors to confirm the noise level resolution).
PS: I want to show how Cosmos ADC sees the signal of 9038D 12kHz@48kHz. No AVG at all. The FFT shows jitter of Cosmos+9038D.

Two questions, what is "-.2-.5dbfs" mean? And what's "no-lad condition"?

One other request. Is it possible to see the FFT using 1kHz@48kHz no averaging?

EDIT: One last question for anyone else. How often do AP machines need to be properly calibrated?

 

[q3cpma]

Is it class compliant?

 

[olivier salad]

What about the clicking issue? Does it exist only on Windows? I've read on discord that using this driver https://drive.google.com/drive/folders/1Z2LnBRPVUVfd46HY6Q79BDKXWgMvP5EY the problem goes away.

 

[IVX]

Two questions, what is "-.2-.5dbfs" mean? And what's "no-lad condition"?

One other request. Is it possible to see the FFT using 1kHz@48kHz no averaging?

EDIT: One last question for anyone else. How often do AP machines need to be properly calibrated?

no-load means: without headphones connected. I have different FFTs here https://e1dashz.wixsite.com/index/9038d
but AVG yet due to way small FFT window-buffer(32K) of AP SYS2522.
No idea how often AP requires calibration, at least you noticed something wrong with the test result.
BTW, CMRR is the AP's simple self-test. My old AP has very good CMRR, however, for the best test result I going to use a battery-powered Android or USB2USB iso board.

 

[IVX]

olivier salad I guess Amir faced the standby mode engaged after 1min no-signal. It was my mistake in the first batch of 9038D, anytime you can switch Off that power-saving mode to avoid these "heartbeats".

 

[buz]

@IVX any chance the PowerDAC will come back? Really like the idea of having hardware eq (currently use the Qudelix but having the nagging upgrade feeling)... If I could wish, LDAC would be nice, too

 

[Jimbob54]

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:
    View attachment 119214
• 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.
  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.

Very cool. You said the volume limit "sticks" regardless of the source. Do all the settings in the pro app stick too?

 

[staticV3]

Very cool. You said the volume limit "sticks" regardless of the source. Do all the settings in the pro app stick too?

Yes, of course

 

[staticV3]

Nice work!

Spotted this, didn't know that Topping's working on a dongle style amp or DAC or a combo

View attachment 119273

I believe that's the A30Pro. Amir wrote A10pro in its review, too.
See here: https://www.audiosciencereview.com/...g-a30pro-review-balanced-headphone-amp.20366/

 

[Jimbob54]

Yes, of course

I'd already just bought the pro app regardless of your answer

 

[Jimbob54]

Yes, of course

Interesting, just plugged the D (early model with standby disabled firmware added) onto the tweak app. Says I need to contact to get special firmware first? Do you have a link pls?

Edit, same response for my 9038S v3

 

[staticV3]

Interesting, just plugged the D (early model with standby disabled firmware added) onto the tweak app. Says I need to contact to get special firmware first? Do you have a link pls?

To update the firmware, you will need a PC running Win7 or Win10.
Here's the update procedure:

CT7601 2018 driver: https://drive.google.com/folderview?id=1uGMGM_9aC4LG_ggWSxGxQTriKDud2EgU

CT7601 2020 driver:
http://comtrue-inc.com/index.php/downloads2/summary/4-ct7601/12-windows-7-10-driver
(the 2020 driver has been causing issues for some users. 2018 works fine though)

Firmware Update Tool with firmware files:
https://drive.google.com/file/d/1q_2D_6x0CSiB-wDffqTxGvr8Do1johkH/view?usp=sharing

To use the App, update the firmware to 'Tweak_9038D_C.hex"