Am I wrong about dongles?

[D13H4RD]

So I had a discussion with a guy about dongles designed for the iPhone and USB-C devices.

 

While I said that many of these dongles do require a DAC and amp of some combo for it to output sound as the signals coming out of those (especially Lightning) are digital and need to be converted to analog, although the other mentioned that those chips inside the dongles may not be a DAC and that the conversion actually occurs inside the phone before reaching the dongle.

 

I'm confused. Which is right?

[Sauron]

As far as I know you are right, usb (or lightning) can't carry an analog signal and therefore the conversion must happen inside the dongle.

[79wjd]

8 minutes ago, D13H4RD2L1V3 said:

So I had a discussion with a guy about dongles designed for the iPhone and USB-C devices.

 

While I said that many of these dongles do require a DAC and amp of some combo for it to output sound as the signals coming out of those (especially Lightning) are digital and need to be converted to analog, although the other mentioned that those chips inside the dongles may not be a DAC and that the conversion actually occurs inside the phone before reaching the dongle.

 

I'm confused. Which is right?

So technically either way is possible -- I'm pretty sure both Lightning and USB-C support analog pass through.

 

However, in the case of the iPhone, I'm the dongle has a DAC/amp in it. 

 

EDIT: USB-C appears to support analog pass through while Lightning appears to not support analog pass through.

https://hardware.slashdot.org/story/16/09/30/2027235/usb-if-publishes-audio-over-usb-type-c-specifications

[D13H4RD]

1 minute ago, Sauron said:

As far as I know you are right, usb (or lightning) can't carry an analog signal and therefore the conversion must happen inside the dongle.

That's kinda what I thought.

 

I remember that for Lightning, Apple touted it as an "all-digital" connector, and if that were the case, there can't be an analog signal coming out of a supposedly "all-digital" port, which means that an analog conversion needs to happen outside the device.

[Vapare]

http://www.makeuseof.com/tag/no-stereo-jack-no-problem-iphone-7-sounds-great/ This might be what you're looking for. They talk about the headphone adapter , "This adapter will house the DAC and amp." It's under the heading "Can I Only Use Apple’s Lightning EarPods Now?" section of the article. 

[Sauron]

8 minutes ago, D13H4RD2L1V3 said:

That's kinda what I thought.

 

I remember that for Lightning, Apple touted it as an "all-digital" connector, and if that were the case, there can't be an analog signal coming out of a supposedly "all-digital" port, which means that an analog conversion needs to happen outside the device.

On top of that the whole idea around removing the jack was supposed to be freeing up space inside the device to allow it to be thinner or have more battery (or from a more cynical point of view, lower production costs and make more money from dongles or lightning compatible/bluetooth Beats headphones). Leaving the DAC in would sort of defeat the purpose.

[AresKrieger]

12 minutes ago, D13H4RD2L1V3 said:

I'm confused. Which is right?

For Apple you are, for Android they are since USB C allows for the proper pass through while lightning does not

[79wjd]

Just now, Sauron said:

On top of that the whole idea around removing the jack was supposed to be freeing up space inside the device to allow it to be thinner or have more battery (or from a more cinical point of view, lower production costs and make more money from dongles or lightning compatible/bluetooth Beats headphones). Leaving the DAC in would sort of defeat the purpose.

The DAC needs to be left in to handle the speakers on the phone. 

[Sauron]

Just now, djdwosk97 said:

The DAC needs to be left in to handle the speakers on the phone. 

Hm, that's true, I hadn't thought of that. But I suppose the extra wiring would still take up more space.

[D13H4RD]

Just now, Sauron said:

Hm, that's true, I hadn't thought of that. But I suppose the extra wiring would still take up more space.

The jack alone does take up some space

[79wjd]

1 minute ago, Sauron said:

Hm, that's true, I hadn't thought of that. But I suppose the extra wiring would still take up more space.

I don't think space is really the biggest reason. Apple has historically killed off legacy components that there really isn't a huge need for/that should die -- sometimes, it's a bit inconvenient at first, but then it starts to make sense/be beneficial (ODD, firewire, floppy, dvi, vga, etc...). Apple wanted to push bluetooth technology forward and knew that manufacturers wouldn't give it any real thought until there was a reason.

[Sauron]

1 minute ago, djdwosk97 said:

I don't think space is really the biggest reason. Apple has historically killed off legacy components that there really isn't a huge need for/that should die -- sometimes, it's a bit inconvenient at first, but then it starts to make sense/be beneficial (ODD, firewire, floppy, dvi, vga, etc...). Apple wanted to push bluetooth technology forward and knew that manufacturers wouldn't give it any real thought until there was a reason.

Unlike, say, parallel ports, wired headphones still have a number of advantages on bluetooth, simply by virtue of not requiring batteries. If they had opted for substituting the jack with a standard digital port (usb-c for example) then I might have accepted it as a necessary step forward, but as it is bluetooth headphones have about the same market they always have and there is no reason for the industry to move from jack cables to lightning since those would only work on apple phones (and who knows for how long given their tendency to not care about in-house retrocompatibility).

[D13H4RD]

I think it would really benefit more if we had some improved short-range wireless solution that allows for the transfer of high-bitrate files at high throughputs without sacrificing quality.

 

Bluetooth 5.0 and aptX are solid steps, but neither are what I'd call "final".