Review and Measurements of E1DA 9038S BAL Portable DAC & Amp

[JohnYang1997]

I recommend to use this as a dac. You can use something like opa1622 evaluation board to pair with it. Just needed external power supply, battery works as well.

 

[Veri]

I recommend to use this as a dac. You can use something like opa1622 evaluation board to pair with it. Just needed external power supply, battery works as well.

You tried it already?

 

[JohnYang1997]

You tried it already?

No. But this should work. Opa1622 evm has balanced input so it is possible to interface with this. I've used opa1622evm before but not eith e1da.

 

[Patrick1958]

Let me get this right :
Connecting an un-balanced wired headphone with and above mentioned adapter from amp to headphone to have some more power routed to the headphones is harmful?

 

[JohnYang1997]

Let me get this right :
Connecting an un-balanced wired headphone with and above mentioned adapter from amp to headphone to have some more power routed to the headphones is harmful?

Potentially harmful to the output device. And should have serious sound quality degradation.

 

[Patrick1958]

Potentially harmful to the output device. And should have serious sound quality degradation.

Makes you wonder why these adapters are on the market. Thanks.

 

[JohnYang1997]

Makes you wonder why these adapters are on the market. Thanks.

It can work the other way around.

 

[Veri]

Makes you wonder why these adapters are on the market. Thanks.

There is a small amount of devices that will work with this adapter (transformer coupled ones if I'm not wrong?).
But yes for the vast majority there is a big chance you will break things! should come with a warning label

 

[Music1969]

You could use your balanced XLR-terminated headphones with an adapter like this: 2.5mm 4-pin to XLR 4-pin female:
https://www.amazon.com/NewFantasia-Balanced-Headphone-Adapter-XDP-300R/dp/B07D7KZ8TL/

Nice.

Did Ghent get back to you?

 

[Veri]

Nice.

Did Ghent get back to you?

So far, no. I think it's a busy time of the year though.

Would be cool if they add some 2.5mm cables to their inventory. Feel free to shoot them an e-mail too, to show them some interest

 

[dropbear]

@Veri @solderdude Thank you, both, I actually wasn't aware of this to apply for headphones as well, I didn't know how it behaves when connected to a passive component such as headphones. Noted. I can add it to the list of cables I refuse to make (I had couple of guys actually asking for XLR>RCA interconnect cables and I have always turned them down immediately as that is the very most simple way to fry that SE-inputting device).

By the way, above, guys, you mention 2,5M > 4FXLR adapter - do you find there is a lack of such adapters?

 

[IVX]

Today I sent #9038Dv0 gerbers pack to make PCB samples. Next few days will try it. I have added:

1) softstart to limit inrush current and let work with mobiles without Y-splitter. Actually, a big output power peaks anyway will off USB OTG power rail ))

2) Seems max power at 16ohm will be limited anyway. 32ohm I hope will produce similar 340mW but @16ohm maybe just 400mW or so
3) Optimized I/V stage for minimal noise, simulations show up to 125dbA, let's see
4) A lot more part on both sides. Becomes expensive.
5) Regarding THD #9038S seems to stay unbeatable. And cost-effective as well. Actually, can't realize why so many people want unbalanced 3.5mm if most of decent HP for sure balanced?

 

[solderdude]

(I had couple of guys actually asking for XLR>RCA interconnect cables and I have always turned them down immediately as that is the very most simple way to fry that SE-inputting device).

3pin-XLR to RCA is easy to make and works great as well.
The other way around is also quite possible.
The reason is that there is a ground available in this case.

Some folks might be interested in 2.5mm TRRS -> 4-pin XLR and maybe 2.5mm TRRS -> 2x 3-pin XLR

 

[solderdude]

Actually, can't realize why so many people want unbalanced 3.5mm if most of decent HP for sure balanced?

That may be because the vast majority of headphones has 3.5mm TRS and/or 6.3mm TRS.
2.5mm TRRS is very rare, about as rare as Pentaconn 5-pin and very few with 4 pin XLR.
These usually are aftermarket cables.

 

[Veri]

3.5mm is most common probably, and easy to use with screw-on 6.3mm adapter
2.5mm is pretty rare for balanced (except w/ iems and daps) since 4-pin xlr seems to be the standard,
4.4mm is even more rare, wish this would get more common...

Some folks might be interested in 2.5mm TRRS -> 4-pin XLR and maybe 2.5mm TRRS -> 2x 3-pin XLR

2.5mm to 2x XLR seems especially niche, only found on some aliexpress stores(?)

 

[dropbear]

3pin-XLR to RCA is easy to make and works great as well.
The other way around is also quite possible.
The reason is that there is a ground available in this case.

Some folks might be interested in 2.5mm TRRS -> 4-pin XLR and maybe 2.5mm TRRS -> 2x 3-pin XLR

Oh, do you mean it by leaving pin 3 NC and to connect pin 2 to tip and pin 1 to the sleeve?

 

[solderdude]

fo

Oh, do you mean it by leaving pin 3 NC and to connect pin 2 to tip and pin 1 to the sleeve?

For XLR to RCA = 2-XLR to center pin RCA, 1-XLR to sleeve RCA
For RCA to XLR = centerpin RCA to 2-XLR and sleeve to 1+3 XLR.

These adapters do not work the other way around.

 

[invaderzim]

Actually, can't realize why so many people want unbalanced 3.5mm if most of decent HP for sure balanced?

My guess is a some people are planning to use it with a regular amp and speakers.

 

[Nathan Raymond]

3.5mm is most common probably, and easy to use with screw-on 6.3mm adapter
2.5mm is pretty rare for balanced (except w/ iems and daps) since 4-pin xlr seems to be the standard,
4.4mm is even more rare, wish this would get more common...

2.5mm to 2x XLR seems especially niche, only found on some aliexpress stores(?)

2.5mm is the most common on DAPs I think, with even some Japanese brands (other than Sony, who only do 4.4mm for balanced) like Onkyo and Pioneer including 2.5mm balanced. Some earphone makers include 2.5mm balanced cables in the box, like Fiio, who even include the second cable in some of their more entry-level earphones. For others, they reserve the inclusion of the 2.5mm cable for their higher-end products. 2.5mm balanced cables are available terminated in MMCX and the 2-pin variants starting for as little as $7. Starting a few years ago when I bought an Onkyo DAP, I started standardizing on 2.5mm balanced for all my headphones including overears (Sennheiser, Onkyo, HiFiMan, and Audio-Technica). My Pioneer on-ear headphones came with a second 2.5mm balanced cable. I carry a FiiO L26 adapter with me so I can plug any balanced headphone into a 3.5mm source:

https://penonaudio.com/fiio-l26.html

And I have a DUNU DC-11 plugged into one of my desktop headphone amp's outputs to let me plug in easily at home without switching cables:

https://penonaudio.com/dunu-dc-12dc-11.html

And I bought a Massdrop 4-pin XLR to 2.5mm TRS adapter when/if I get a desktop headphone amp with an XLR output:

https://drop.com/buy/massdrop-4-pin-xlr-to-2-5mm-trrs-adapter

At this point almost all my headphones are 2.5mm balanced, which wasn't that difficult or expensive to do, the aftermarket cables I got were an ergonomic improvement in most every case, and the adapters I use don't add too much inconvenience. I don't get to use any inline mics or volume controls, but I was never a fan of those anyway.

 

[Veri]

And I bought a Massdrop 4-pin XLR to 2.5mm TRS adapter when/if I get a desktop headphone amp with an XLR output:

https://drop.com/buy/massdrop-4-pin-xlr-to-2-5mm-trrs-adapter

Ah yes I wanted to buy this one but it was a pre-order of more than a month at a time, typical massdrop. So I found a nice alternative:
This guy makes the same thing but with actual neutriks instead of whatever massdrop is using. Same price, too!
https://www.koycables.com/store