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d6jg
2019-04-27, 10:38
Does anyone know for certain what the DAC in the official Apple Lightning Headphone adapter is capable of?
Iíve read 24/96 somewhere but cannot find a definitive answer.
Reason for asking is that I have just upgraded to an iPhone 8 so have lost the 3.5 jack socket.
Iíve used a HiFiMeDIY USB DAC with the camera kit converter on occasions but it is a little on the quiet side (I do have a mini headphone amp as well but carrying all this is a bit cumbersome)
Main use is iPeng in playback mode with 16/44.1 Flacs but some 24/96 stuff as well.
Edit. Headphones are B&W P7s which do take a bit of driving.

pippin
2019-04-28, 14:16
Hard to know for certain since it's hard to debug, but I'd be extremely surprised if it's more than 48/16.
That's what AirPlay uses (44.1/16 and 48/16 as ALAC) and my guess is iOS transcodes to that before the DAC.

That's usually how these things work under iOS, iOS transcodes to whatever capability the chosen audio route supports.

iPeng currently supports up to 96/24 natively but that's going to change in the future, at least optionally.

There have been comparison tests with older iPhone DACs and the DAC in the adapter seem to be inferior. Which isn't really surprising given the ultra-small package size and power availability. So if you really care about SQ you should use a different adapter or lightning capable headphones.
It's probably still better than Bluetooth, though...

Paul Webster
2019-04-28, 15:09
Background reading on it at https://ifixit.org/blog/8448/apple-audio-adapter-teardown/

d6jg
2019-04-29, 02:13
Hard to know for certain since it's hard to debug, but I'd be extremely surprised if it's more than 48/16.
That's what AirPlay uses (44.1/16 and 48/16 as ALAC) and my guess is iOS transcodes to that before the DAC.

That's usually how these things work under iOS, iOS transcodes to whatever capability the chosen audio route supports.

iPeng currently supports up to 96/24 natively but that's going to change in the future, at least optionally.

There have been comparison tests with older iPhone DACs and the DAC in the adapter seem to be inferior. Which isn't really surprising given the ultra-small package size and power availability. So if you really care about SQ you should use a different adapter or lightning capable headphones.
It's probably still better than Bluetooth, though...

Thanks. Iíve got a camera converter so Iíll try a Dragonfly with it.

d6jg
2019-04-29, 02:22
Background reading on it at https://ifixit.org/blog/8448/apple-audio-adapter-teardown/

Interesting but still inconclusive.

d6jg
2019-04-29, 12:32
@pippin
Leaving aside lightning headphones do you use a usb DAC with an ithingy? If so which?

pippin
2019-04-29, 12:38
No, I usually donít. I do have an old Pure digital docking adaptor (with DAC) I used for a while and which I still use for testing and I do have an external DSD DAC I use for testing but Iíve got so many good, dedicated players around here that I canít even use all of those so beyond testing things I donít actually use iPhone accessory DACs.

What do use a lot with iPhone, iPad and iPod is headphones but the are either AppleĎs or indeed analog headphones I use with this Apple adapter.

pippin
2019-04-29, 12:39
That said... I might be tempted to compare the two different Apple adapters I have because it might become more relevant this fall (hopefully so...): the lightning-to-analog adapter and the USB-C-to-analog one. Itís a bit bigger, maybe it also has different tech?

d6jg
2019-04-29, 12:47
No, I usually donít. I do have an old Pure digital docking adaptor (with DAC) I used for a while and which I still use for testing and I do have an external DSD DAC I use for testing but Iíve got so many good, dedicated players around here that I canít even use all of those so beyond testing things I donít actually use iPhone accessory DACs.

What do use a lot with iPhone, iPad and iPod is headphones but the are either AppleĎs or indeed analog headphones I use with this Apple adapter.

Thanks
Generally I use other players - sb3, Pi etc - with iPeng as the controller but I do use iPeng in playback mode and headphones when my wife is watching TV in the same room.
Iíve got the camera kit and use a hifime usb DAC with my b&w p7s but this isnt ideal as the volume is a little limited. The apple lightning adapter seems to allow a little more volume presumably because it doesnít use much current but like you suggested I think the SQ is reduced.
What Iím looking for is something like the hifime - does 96/24 - but allows more volume.
I have Bose QCs which are Bluetooth for travelling purposes.

d6jg
2019-04-29, 12:52
Perhaps looking at it another way - does iPeng ďlimitĒ volume in any way? Foobar2000 on the iPhone playing the same flacs seems louder.

pippin
2019-04-29, 15:18
No, unless you enable an equalizer or use replay gain in LMS, iPeng plays the raw audio up to 96/24

d6jg
2019-05-06, 07:13
I can now report that the Audioquest Dragonnfly Black works perfectly with an iPhone 8 (camera kit converter needed) and has quite a bit more oomph than the Hifime DIY DAC I was using. The dragonfly will support up to 24/96 and is a good match for my difficult to drive B&W P7s