The Computer Audiophile

Now that Amazon Music HD has been live for about one month, many in the Audiophile Style community have had a chance to test it on numerous platforms. The results have been all over the board. Some have said the sound is different than other services, possibly even louder. Others have expressed frustration over getting music to output to a DAC without running it through a virtual spaghetti of operating system audio paths. I decided to gather up some devices, run some tests, and write down the current status of using Amazon Music HD. The interface, to me, is a work in progress and I hope a ton of progress will be made. However, I'm not going to focus on usability in this article. Many audiophiles are willing to suffer a bit with respect to usability, if the payoff is better sound quality. Thus, I'm going to dive deep into Amazon Music HD to show people how to get the best sound quality from the service and what platforms to steer clear of, if sound quality is critical. (Lenbrook brands NAD, Bluesound, etc...) Let's start with one of the few platforms to integrate Amazon Music HD into HiFi products, BluOS. I have an NAD C 658 DAC and a Bluesound Pulse 2i speaker. Using the BluOS app for iOS I easily added Amazon Music HD to the list of music sources. Streaming music to the Pulse 2i speaker, the only indication about music format a listener has is a little logo that says either CD or HR (screenshots below). Like most services, there are multiple versions of albums. Using Neil Young's Greatest Hits as a test album, both available versions on Amazon Music HD indicated HR when played via the BluOS iOS app. This HR logo only appears once the music has started playing. Via the Amazon Music HD desktop app, I can see this album is only available at 24/192, so I can only guess that's what's streaming to the Pulse 2i. I have no idea if the audio is bit perfect as the Pulse 2i doesn't feature a digital output for me to connect an analyzing device. The sound quality from the Pulse 2i is terrific, but that's a story for another day and review. Streaming Amazon Music HD through the NAD C 658 running BluOS was a similar experience to the Pulse 2i in that almost no indication of music format was given. I say almost because there is one screen on the main physical display of the C 658 that offers a bit of information but it's confusing. Selecting DISP on the C 658 remote scrolls through some information including screen that says "Quality." When streaming CD quality music from Amazon, music that Amazon calls HD, the NAD says CD. When streaming high resolution music from Amazon, music that Amazon calls Ultra HD, the NAD says HD. Whats more, the BluOS iOS app says CD or HR based on the music being streamed. I know these are early days for Amazon and its integration partners, so this is really just information at this point. There's nothing wrong with the Pulse 2i or the C 658, just some leading edge quirks. The BluOS devices I have, both hardware and software, don't indicate a sample rate and don't indicate with the music is being streamed without alteration. That's neither good nor bad, it's just how the devices and apps work. The really positive thing is that Amazon Music HD is fully supported by all the BluOS devices, even a really old P300 speaker I have sitting around my house. I used the new Sonos Port for testing Amazon Music HD. I figured the newest hardware, that replaced the old Sonos Connect, would be the best option. Sonos, to me, is like the Fred Couples of audio. Freddy always went for the center of the green and played the odds, versus a player who went for the pin and took chances. I know, a golf reference. That's a first for me here on Audiophile Style. Anyway, Sonos plays it safe by supporting 16/44.1 CD quality and nothing more. In addition, it supports a pre 1998 802.1D STP protocol that should've been updated years ago on its devices. This causes many problems with Ubiquiti based networks like mine. Anyway, middle of the road Sonos streams Amazon Music HD without any fanfare. Add the service and start streaming and it all comes down to the Sonos Port at 16/44.1/ Yes, it all streams at CD quality even if the track is 24/192. For example, Neil Young's Greatest Hits is only available at 24/192 on Amazon Music HD. Streamed through Sonos it plays at 16/44.1 and isn't bit perfect. Streaming Pearl Jam's Live on Two Legs album, that's only available in CD quality, playback is bit perfect every time on Sonos. That's the Sonos steady CD quality for ya. I'm unsure where the Neil Young and other high resolutions albums are altered or if an MP3 version is what's actually sent to the Sonos device. Addition testing will be required. I also streamed this album from Tidal and Qobuz. I found out Qobuz has the 24/96 and 16/44.1 versiosn of the album while Tidal had the 16/44.1. Both Tidal Qobuz play bit perfect through Sonos for DC quality. Selecting the high resolution Neil Young on Qobuz and streaming it to the Sonos Port, the music is downsampled and not bit perfect. The bottom line is that Sonos is bit perfect with Amazon Music HD, as long as the content is CD quality 16 bit / 44.1 kHz, what Amazon calls HD. Amazon Music HD in combination with Windows 10, is a complete joke. There's no exclusive mode, WASAPI, or ASIO available. I thought I'd be able to squeeze bit perfect playback out of Windows by using a little trickery, but I was unable to do so. Nothing that streams from Amazon Music HD on a Windows machine, using the Amazon desktop app, is bit perfect. It's all altered. Need I say more? Correct bit depth and sample rate showing, but not playing bit perfect. I used an iMac Retina 5K and MacBook Pro, both running macOS Catalina 10.15, with the Amazon Music HD desktop app. One annoyance I found was that the Amazon desktop app on both machines said it was the newest version, but the version numbers were different. There was nothing I could do to update the app (short of downloading it again), other than wait for about 30 minutes. After this time, the app said there was an update. Anyway, with both machines on the same Amazon Music HD desktop app version and both machines outputting audio to a Berkeley Audio Design Alpha USB and Alpha DAC RS3, I was able to test quite a bit. Neil Young's Greatest Hits was bit perfect on both machines through Tidal (16/44.1), Qobuz (only the 16/44.1 version is verifiable), and Amazon Music HD (24/192). The thing with Amazon Music HD on macOS is that the user must manually set Audio Midi to the sample rate s/he wishes to play. Herein lies another issue. How does the user know which sample rate is being streamed from Amazon? It's all a guess. Given that Neil Young offers all hs music at 24/192 I took a guess and set Audio Midi to 192. I got luck the first guess and it streamed bit perfect. Ultra HD according to Amazon means anything above 16 bit and 44.1 kHz. Thus, one can't just look at the Ultra HD logo and immediately know what to set in Audio Midi. The b bottom line with Amazon Music HD on macOS is that it's bit perfect, as long as the user sets the correct sample rate for the music. If one just streams 16/44.1, it won't be an issue. But, for those of us into true high resolution, this is a big pain and it's what spurred the development of iTunes add-ons like Amarra, Pure Music, and Bit Perfect way back in the day. I have no desire to go back to the manual sample rate switching days. I tested iOS with my iPhone 11 Pro running version 13.1.3. I connected my phone to the same Alpha USB and Alpha DAC RS3 for testing. Setting a baseline, I played all sample rates via Qobuz bit perfectly through my iPhone 11 Pro. Just browse, click, and play. Switching to Amazon Music HD for iOS showed a major design flaw in this app. The Amazon app queries one's audio device, in my case the Alpha USB, EMM Labs DV 2, and dCS Rossini, for its highest sample rate and sets the audio output to 192 kHz if the highest rate is at or above 192 kHz. Thus, whatever music was played via the Amazon app, it was sampled at 24/192 because that's the max of the Alpha USB, and the other two DACs support higher rates. This same behavior can be witnessed using an AudioQuest DragonFly as well. The Amazon Music HD iOS app will set the DragonFly to 96 kHz no matter what's playing. In this configuration, playing Neil Young's Greatest Hits worked perfectly. The album streamed bit perfect through my iPhone. Switching to any other album that wasn't available at 24/192 meant that the audio was altered / resampled before getting to my audio system. There's no way to manually set this sample rate int he app, like there is in macOS. I suppose one could get a D to D converter that supports a max rate of each sample rate and connect it to an iOS device based on the music selected. Oh wait, audiophiles are a strange bunch, but that is a bridge too far. The bottom line is that the Amazon Music HD app is majorly flawed with respect to its inability to switch sample rates. The Qobuz app can switch sample rates without an issue. Tidal doesn't offer anything other than 16/44.1 (sure there's lossy MQA but this article is about bit perfect lossless), so I couldn't test for sample rate switching ability. If using Amazon Music HD on an iOS device, only some of one's music will be bit perfect. Wrap Up Given that these are early days for Amazon Music HD, I expect things will improve. However, I wouldn't be surprised if they didn't. Communication with Amazon has been nearly impossible and the company has shown zero interest in the consumers of its HD tier. There isn't a platform I know of that works perfect with Amazon Music HD, although BluOS likely has the best shot at getting things right. I need to get a Bluesound Node 2i for further Bluesound testing. For now, all other platforms are severely limited in either capability or usability with Amazon Music HD.