Volume keys with an external USB DAC

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Hello,

I'm using PA 3 with my HTC 10 (internal Hi-Res DAC), to which sometimes I connect an external USB DAC/AMP (iBasso D-Zero mkii).

Everything seems to work fine: the external DAC device is recognized by PA, with the correct parameters (24 bit - 96kHz).

There is one thing that isn't clear to me: when using the external DAC, the volume can still be managed by the volume up/down keys of my smartphone,

 while I expect that this shouldn't happens, since the digital output is passed to the external device that should do all the work (DAC + AMP + Volume).

With my other players (Neutron and UAPP), when using an external DAC, the volumes keys on the smartphone do nothing, the volume can only be managed by the external device. 

Any ideas?

Thanks!

Stefano

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really? 🤔

nobody knows if Poweramp actually use the external DACs connected to USB? 

[maxmp]

Volume keys as you noticed, work with USB as volume control is implemented by Android. As for other players (esp. using custom USB audio implementation) - I can’t comment - please ask on appropriate app forum. Thanks! 

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sorry maxmp, I don't undestand your answer, or maybe my answer is badly written. 

When an external DAC is connected via USB, Poweramp bypass the internal DAC of the smartphone? or the internal DAC is used in any case? 

Said in different words: is worth buying an external DAC to improve the sound quality, if I use Poweramp as my favourite player? 

[AE9]

I have the same question

[andrewilley]

Poweramp can use external USB DACs, but reliability can be a bit hit-or-miss as a lot depends on the external hardware and how it interacts with your particular phone/tablet. It might be an idea to see if anyone else is using the same combination successfully?  

Andre

[AE9]

Thanks for your reply. What I am trying to ask is, when you connect an external DAC to Poweramp, is there any way to find out if the signal being passed from Poweramp to the external DAC has already been processed by the smartphone's own DAC? Or is the phone's internal DAC bypassed in favor of the external DAC? The external DAC would presumably produce a sound output in both cases, but in the first case it would not have actually done the conversion from digital to analog. 

[andrewilley]

36 minutes ago, AE9 said:

Thanks for your reply. What I am trying to ask is, when you connect an external DAC to Poweramp, is there any way to find out if the signal being passed from Poweramp to the external DAC has already been processed by the smartphone's own DAC? 

It shouldn't be, the phone's DAC basically only goes to its own speaker or to its AUX (headphone) socket. It has to be digital to get passed to the next DAC unit, otherwise it would just be an analogue-to-analogue converter.

Andre

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On 2/3/2020 at 8:19 PM, andrewilley said:

It shouldn't be, the phone's DAC basically only goes to its own speaker or to its AUX (headphone) socket. It has to be digital to get passed to the next DAC unit, otherwise it would just be an analogue-to-analogue converter.

Andre

Isn't the USB capable to handle both analog and digital signals? When I attach my D-Zero Dac/Amp to the smartphone a system message ask me to "Choose an app for the USB device", the list shows Neutron and UAPP players, not Poweramp. Why PA isn't listed as an USB device "handler"? Which one of PA Outputs has to be chosen in order to bypass the internal DAC and stream directly to the USB connected one?
I admit to be rather confused ..

[andrewilley]

If you choose a USB DAC as the Output method in PA, the audio will be sent digitally to the DAC. There's no point in trying to send an analogue audio signal to a DAC - there's a clue in the title "Digital to Analogue Converter".

Andre