iOS HD output via DAC (feature request)

Plex Labs
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1

Hello,

While sample rate + bit depth switching support via lightning to DAC via the USB dongle has been supported on iOS for some time in applications such as VLC and Tidal, it has now also officially come to Apple Music.

Considering Plexamp already supports showing the “codec” flags of the track it would be great if it would output at the sampling rates + bit depth when listening via DAC.

Are there any plans to add this feature to upcoming versions?

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On the list.

2 Likes
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That sounds great, looking forward to it. just a quick ask, can you support DSD in that too? thanks

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We decode DSD to PCM inside Plexamp.

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Thanks for the reply. any chance we could have the choice to decode DSD on server, or pass it to the client? I do have apps that will output dsd directly from an iPhone to a usb dac, but Plexamp supporting it would be great!

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Sorry, no plans for this. We handle decode in our pipeline.

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oh, sorry, I misread that as you decode in server. client side decode is good :slight_smile:

Could I request that you put DSD output to a usb dac on the roadmap, either through direct DSD or DoP (where the DSD data is wrapped in PCM frames to ease passing it to a DAC)? I think it would be a nice feature upgrade.

Many thanks

1 Like
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I’m sorry, but that’s not the way the audio pipeline is designed.

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Any update on the HD audio piece? I was reminded on a reddit thread where someone asked and so I tested it all again to see if there had been any update and so far no.

as a matter of interest, I don’t suppose anyone could just rename how DSD is referenced in the dashboard could they? “DSD_LSBF_PLANAR (Stereo)” doesn’t roll off the tongue… :slight_smile:

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Progress on iOS and macOS.

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I assume that means that there is some… and we’ll find out soon? :slight_smile:

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SO MANY QUESTIONS :laughing:

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what can we say, we’re keen :slight_smile:

1 Like
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Are you able to elaborate a bit on what “HD” audio will entail for macOS? I’m currently using an external DAC+Amp with my headphones, and use PlexAmp on my Mac feeding the DAC via USB. I would very much welcome a “cleaner” HD audio path. I also currently use EQ for my headphones, via the FabFilter Pro-Q3 plus-in. I’d love for PlexAmp to natively support audio-plugins instead of relying on SoundSource.

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It’ll tweak the sample rate of the DAC to match source in some cases, and adjust the entire pipeline to match. Bit-perfect-ish.

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That’s good progress! Will PlexAmp be enabled to select an output device (e.g. USB DAC) for exclusive use? And if that is on the road map, I’d need audio plug-in capability for PEQ.

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Nope, that’s way more complicated and the only good reason I know for it is stuff like MQA which we are not planning to support.

1 Like
18

My understanding is that no “support” is needed from the software player if the first “unfold” is not handled by the player. Instead, if the player passes all 16-bits bit-perfect to an MQA DAC, the DAC will recognize the MQA flag in the LSB and perform the Core Decoding (44.1->96, first unfold) internally.

This assumes that the DAC is capable of the first unfold though; some are only renderer (2nd).

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I am sort of achieving this by selecting my DAC as my Plexamp output device, but then switching the rest of system audio [macOS FWIW] to a different output device like internal speakers.

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I would agree; in practice I couldn’t find any cheap DACs which handled the first unfold :sweat_smile: