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Q I am wondering how to best access high-res audio formats on music services. I have a Marantz SR7015 receiver in my system and have tried streaming from Amazon Music HD to it over Bluetooth from my iPad using the receiver’s HEOS app. The app shows resolutions from 16-bit/44.1kHz all the way up to 24 bit/192kHz — something I didn’t think was possible with Bluetooth! Here’s my question: Will I get the same resolutions if I make a hardwired connection from iPad to AVR using an AudioQuest DragonFly Red USB DAC? —Paul Giovino, via email

A First off, you were right about the limitations of Bluetooth when it comes to streaming lossless high-res audio. Bluetooth tech transmits audio wirelessly using lossy compression that discards data. Even the latest and greatest Bluetooth version, AptX Adaptive, a format that claims support for high-res audio, uses lossy compression. Beyond this key limitation, Apple products don’t even provide support for the more basic Bluetooth AptX version, so high-res audio streamed from an iPad via Bluetooth is a non-starter.

I should further point out that when you use the HEOS app to play music on your Marantz, you are not streaming from the iPad, but using the app to control the receiver’s built-in HEOS platform, which streams it directly over a wired or Wi-Fi network connection. That’s why you see tracks played in up to 24/192 resolution when using Amazon Music HD, which has native integration with the HEOS platform.

As for your DragonFly question, yes, it is possible to get high-res Amazon Music HD playback by making a hardwired connection between iPad and AVR using a USB DAC. That approach will be more complicated, however, since iOS devices like the iPad require a Lightning-to-USB camera adaptor to connect to an external USB DAC. In this scenario, you will have two separate devices daisy chained between the iPad and AVR. Also, the maximum resolution supported by the DragonFly Red is 24-bit/96kHz, as opposed to the 24-bit/192kHz you can get when streaming Amazon Music HD via HEOS.

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