Stand-alone, portable DAC with battery

[PenguinMusic]

Hi guys,

A few months ago, I bought a bunch of Xiaomi Bluetooth Adapters for Audio.
The thing is pretty simple : a small and light white box with a USB port (just for charging purpose) and a mini jack.
You just power it up, pair it with your BT player (computer, phone...) and you can use every headphone as a Wireless bunch of headphones.
The price for the device is incredibly affordable as I got 8 of those for about 50€ (they were on sale : by one, get the second for free... So I bought 4 and got 8

My question is : how do those thing work ? Do they include a DAC ? Do they include an Amp ?
Is the sound decoded before it is sent to the device or is it decoded after it is received ?
I would like to know if it can be worth to upgrade it with, say, a Fiio BTR1 or a Qudelix 5k ?

Thanks for your explanations/thoughts...

Regards.

 

[M00ndancer]

it's a DAC with circuitry for powering your headphone and a BT receiver. The sound is sent from your BT transmitter and received by the Xiaomi adapter. So the sound is processed like this.

Phone (digital) -> endoded and lossy compressed to a BT signal -> Xiaomi -> decoded and expanded -> converted to analogue signal and amplified -> headphone
But there is a downside with it, as far a I can tell it doesn't support any other audio codecs than standard SBC. Depending on who you ask SBC is the worst of the BT codecs. Preferably you want AptX HD or LDAC codecs for the best sound. RTINGS have an interesting article about the differences, and it's not conclusive.
The takeaway is that they are fine, and for that price, wow! For more options that may sound better go for a BTR-1 or the on paper superior Qudelix. Depending on your use case I would go for the longer battery times.

 

[PenguinMusic]

Hi,

Thanks for your reply...
That answered my question : if there are different codecs, when is the encoding done ? At signal departure, or at signal arrival ? Now I know it is done at the the signal departure, so when it goes out the device (computer, phone, DAP...).
And I assume that any BT headphone works the same... I, for instance, have the B&0 H9 mkIII. Superb comfort (can have it on for several hours) and I really like the sound. Given B&0's expertise in the digital amp domain (I think all ICE digital amps are under B&0 patent...) can I assume that a device like the BTR3 will probably won't offer really better sound than the built-in circuitry ?

If you have an idea about those...

Regards.

 

[PenguinMusic]

it's a DAC with circuitry for powering your headphone and a BT receiver. The sound is sent from your BT transmitter and received by the Xiaomi adapter. So the sound is processed like this.

Phone (digital) -> endoded and lossy compressed to a BT signal -> Xiaomi -> decoded and expanded -> converted to analogue signal and amplified -> headphone
But there is a downside with it, as far a I can tell it doesn't support any other audio codecs than standard SBC. Depending on who you ask SBC is the worst of the BT codecs. Preferably you want AptX HD or LDAC codecs for the best sound. RTINGS have an interesting article about the differences, and it's not conclusive.
The takeaway is that they are fine, and for that price, wow! For more options that may sound better go for a BTR-1 or the on paper superior Qudelix. Depending on your use case I would go for the longer battery times.

Just to reply to another statement : the B&0 H9i supports SBC, AAC and apt-x and of course non A2DP codes like HSP.
It is really easy to tell when you're using HSP. It is quite barely listenable

But I must admit that making a blind test difference between SBC, AAC and apt-x is a little more challenging and I think that my now 50 years old ears can't really tell the difference, at least at first listen. Once I get accustomed to the sound of a coded, I MAY (but not sure) be able to tell the difference... but even that is not for sure.

If I go for one of those devices like the BTR it is because they support LDAC and apt-X HD, which will maybe make a difference. Will probably order them on Amazon... so I can return them if I am not able to hear an improvement over the on-board circuitry of the B&O H9...