- Written by Robert Kozel
- Published on 18 April 2011
- Marantz NA7004 Network Music Streamer
- Page 2: Design of the Marantz NA7004 Network Music Streamer
- Page 3: Setup of the Marantz NA7004 Network Music Streamer
- Page 4: In Use - Internet, USB Connectivity, Home Network and Control with the Marantz NA7004 Network Music Streamer
- Page 5: The Marantz NA7004 Network Music Streamer On the Bench
- Page 6: Conclusions About the Marantz NA7004 Network Music Streamer
- All Pages
Almost every manufacturer these days is including some type of network support in their products. From receivers that connect to home music servers and disc players that stream music and video from the internet, we have lots of options for enjoying content with our home entertainment systems. While Marantz has been including network support in their products for a while, they have not offered a stand-alone network streamer until now.
The Marantz NA7004 is designed to be a dedicated network audio player (i.e., "streamer" - which acquires the music from a server that stores music rather than having music stored within its own chassis). It does not tackle video, but it does all things audio. Whether you have music stored on your iPod, iPhone, iPad, a Windows or Apple computer, a USB drive, or you just use an internet service like Pandora, Rhapsody, or Napster to enjoy your music, the NA7004 offers a solution to enjoy that music with your existing home entertainment system. This is no easy task given the wide array of components, file formats, networking challenges and computer software involved to deliver music over a home network. Let’s take a closer look at the capabilities of the Marantz NA7004 and see how well it performs as a network audio player.
- Design: Network Music Streamer
- Codecs: MP3, WMA, MPEG-4 AAC, WAV, and FLAC
- DAC: Cirrus Logic CS4398
- MFR: 2 Hz – 50 kHz - 3 dB
- THD+N: 0.001% @1 kHz
- Outputs: RCA Analog, Headphone, Coax, Toslink Optical Digital
- Inputs: Ethernet, Coax, Toslink Optical Digital, USB (2)
- Dimensions: 14.25" H x 17.4" W x 13.5" D
- Weight: 14.33 Pounds
- MSRP: $799.99 USA
The first thing you notice about the Marantz NA7004 is that it is a full-size audio component. The player weighs just over 14 pounds. The center portion of the front panel is made from brushed aluminum, and the left and right side panels are made from curved resin which gives the player a more refined appearance. On the top edge of the player you will find a silk-screened DLNA certification logo as well as a sticker which states that the NA7004 is compatible with Microsoft Windows 7.
The front of the player is organized around a central control panel which contains a large Organic Electroluminescence Display (OELD) display. The display offers up to three lines of crisp white text and is very easy to read. Under the display are four transport buttons for Reverse Skip, Forward Skip, Stop and Play/Pause. To the right of the display is a set of cursor buttons surrounding an Enter button. Below the cursor controls are buttons for Display, the M-DAX filter and a headphone jack and level control. To the left of the display is a front USB input for an iPod or USB device as well as a small knob which can be used to select the player’s input source. The Power button is on the far left as well as a small LED to let you know that the player is in Standby mode.
Moving on to the back of the player, you find one set of stereo RCA output jacks as well as optical and coaxial digital outputs should you want to bypass the analog stage of the player. There are three additional digital inputs including optical, coaxial, and USB. The digital inputs allow you to use the NA7004 as a D/A converter. Above the digital inputs is the all important LAN connection so the NA7004 can join your home network. The NA7004 does not include support for wireless networking so you need to connect the NA7004 directly to your existing network or purchase a separate wireless networking adapter. The rear panel also contains remote control jacks, an infrared control jack, and an RS-232C connector for integration with remote control systems. The last connection is for the M-XPort, which allows for the connection of an optional wireless RX101 Bluetooth receiver.
A look inside the player provides a small glimpse at what Marantz put into this audio player. The main circuit board, which handles all of the digital inputs, is powered by an Analog Devices SHARC 21367 processor. To the right of the player is a very large circuit board which is dedicated to the analog output stage of the NA7004. This board makes use of symmetric circuit paths for both the left and right channel and also makes use of Marantz-proprietary HDAM-SA2 discrete amplifier modules in the output stage to optimize performance. You can see the network interface circuitry on the small raised board at the rear of the player. The NA7004 also uses a Cirrus Logic CS 4398 24-bit/192 kHz D/A convertor.
The NA7004 provides integration via several software technologies. The NA7004 is a DLNA (Digital Living Network Alliance) version 1.5 certified DMP (Digital Media Player) and DMR (Digital Media Renderer). This means that the NA7004 not only plays media it finds on a DLNA server, it also receives and renders music sent from a DLNA controller. The NA7004 is also compatible with Windows 7 and supports Microsoft’s Play To functionality which allows you to stream audio directly from a Windows 7 PC. Finally, the NA7004 is certified for Apple’s AirPlay technology which allows you to wirelessly stream music from iTunes as well as Apple devices. The AirPlay technology is available for a separate upgrade fee directly from the Marantz web site. We will explore the DLNA, Play To, and AirPlay functionality in more detail later in the review.
As for internet services, the NA7004 provides access to internet radio via the vTuner service as well as the free Pandora personalized radio service. If you subscribe to the fee-based Napster or Rhapsody music services, then you are in luck because the NA7004 supports those services as well. From a format perspective, the NA7004 supports WMA, MP3, WAV, MPEG-4 AAC, and FLAC.
The inclusion of FLAC (Free Lossless Audio Codec) is a welcome addition since the FLAC format is a very popular open source format for the lossless encoding of music. FLAC is also a popular format offered by online music stores that sell high resolution audio tracks.
The remote for the NA7004 is well organized and fits nicely in your hand. The black plastic surface of the remote is textured to make it look like brushed aluminum. The remote is not backlit but does allow you to control the input and volume of a compatible Marantz receiver.
Marantz also provides an application called Wizz App which is available for free on Apple’s App Store. The Wizz App allows you to control the NA7004 from your favorite Apple iPod, iPhone, or iPad.
Marantz also provides a very basic web application which allows for some control directly from a browser. This application was really slow and didn’t provide as much control as the main menus on the NA7004. I would not recommend this as an everyday interface for theNA7004.
Setup of the NA7004 was a breeze. I connected an Ethernet network cable from the NA7004 to my router, a pair of RCA cables to an input pair on my receiver, the power cord, and I was good to go. I turned on the player and the NA7004 automatically configured itself via DHCP on my network. After a couple minutes of auto-configuration, the NA7004 came up on Internet Radio as its default input. The vTuner application determined where I was in the world and automatically populated a list of local channels. I selected a local channel and was listening to music. I was delighted with just how simple this device was to get up and running.
Once the basic network connection has been made, there are a few more things to consider. If you are interested in Rhapsody, Napster, or Pandora, then you must sign up for an account with those providers using your favorite internet browser. You are not able to create new accounts for those services directly from the NA7004. In my case, I tested the NA7004 using my Pandora account. To enter your Pandora credentials, you navigate to the “Network” menu, select “Pandora Account”, and then enter your email address and your password. That’s all there is to it.
Since the NA7004 relies on software to function, it is a good idea to make sure that the NA7004 is up to date with the latest firmware. The NA7004 allows you to update the player’s firmware directly from the internet. Simply navigate to the “Other” menu and select “Firmware Update”. This menu allows you to check for an update and the player will give you an approximate estimate for how long the process will take. Once you’ve decided to upgrade, simply select “Start” and the player takes care of the rest. The player will give you status updates during the process and will warn you to not unplug the NA7004 while the update is taking place. The process took about 17 minutes which was a bit longer than the original 11 minutes that was estimated.
If you want to make use of the optional AirPlay functionality with the NA7004, then you need to go to the Marantz site and purchase a non-refundable AirPlay upgrade for $49.99. This is a onetime upgrade fee for the NA7004 and the Marantz web site requires that you enter some important information such as your model number, an upgrade ID, serial number, and the MAC address of the player. All of that information is easy to obtain directly from the menus in the NA7004. The Marantz web site also has a help file which walks you through the process. Once you enter the information and pay for the upgrade, Marantz authorizes an upgrade package for the NA7004. This took about a day for my review player. To activate the upgrade, you navigate to the “Add New Feature” menu and select the AirPlay upgrade package. The NA7004 will then go through an upgrade process similar to the firmware update. When the process is done, you will be able to use AirPlay with the NA7004.
If your home networking environment requires a more advanced configuration than typically provided by DHCP, the NA7004 provides a comprehensive menu to make any necessary changes to the player’s network configuration. The last setting that you should consider changing is “Network Standby”. Although enabling this function consumes some additional power while the NA7004 is in Standby mode, the function allows the NA7004 to automatically turn on when it receives a network request from an application in your home network. I will discuss this functionality in the next section.
In Use - Internet, USB Connectivity, Home Network and Control
All of the various functions on the NA7004 are accessed by selecting one of eleven inputs. Selecting an input is as simple as turning the small knob on the front of the player or using the remote or the Wizz App. The front panel on the NA7004 shows you which input you are currently selecting and it shows you the number of that input (e.g. 2/11).
This is a really nice touch since it allows you to see exactly where you are in the menu structure. With eleven inputs, the NA7004 offers a lot of connectivity options. In this section I will cover internet services, USB connectivity, home network connectivity, control applications, and some final thoughts on the sound. I tested the NA7004 with an Anthem Statement D2 processor, a Rotel RB-1080 amplifier, Definitive Technology BP-3000TL speakers, and cables from Cardas and Monster. Internet connectivity was provided via a 6 Mbps DSL connection.
The first major feature on the NA7004 is internet radio. The vTuner software provides a comprehensive list of streaming audio content from all across the world. Whether you are in the mood for some music from your own backyard, or from your favorite city or radio personality around the globe, the NA7004 provides a simple interface to find that station and stream the content to your player. The interface shows you the name of the channel and displays the name of the content that is currently playing. If you press the Display button on the front panel, you can also get a sense of how that content is being streamed.
I frequently saw content in WMA, MP3, and AAC formats at transmission rates of 16, 32, 64, 128, and 320 kbps. This also gives you a sense of why some stations sound so much better or worse than others. I generally have low expectations when listening to internet radio, but I was frequently surprised at how good some of the channels sounded on the NA7004. For example, one of our local university stations, WJCU 88.7 FM, was streaming at 128 kbps while major stations here in Cleveland were only streaming at 64 kbps. The difference was very noticeable. At the other end of the spectrum was Linn Radio streaming at 320 kbps. This offered a superb listening experience on the NA7004 and also gave me a chance to preview some of the content in Linn’s high resolution audio store. The NA7004 allows you to add up to 50 internet radio stations to a “Favorites” list. The list can be directly accessed via the “Favorites” input on the NA7004.
The next major feature is Pandora radio. In case you are not familiar with Pandora, this free internet music service allows you to pick a song or artist and Pandora will then create a custom channel with other songs that are similar to your selection. The NA7004 allows you to manage up to 100 Pandora channels.
The Pandora menu offers access to any Pandora radio channels that you have already created as well as the Quick Mix menu which offers the option to shuffle selections across your favorite channels. The Pandora interface also allows you to quickly create a new channel directly from the NA7004. You can enter an artist’s name or use the search function to find what you are looking for. Once the new channel is created, the NA7004 adds it to your channel list and the music starts playing. Pandora streams in the MP3 format at 128 kbps. I was generally pleased with the quality of Pandora audio from the NA7004. If you haven’t used Pandora, I recommend that you try it if for no other reason than to discover other artists that might match your tastes.
Pandora pays for its services via advertisements which are shown in a traditional browser environment. While there are no advertisements on the NA7004, you are still limited to the Pandora use restrictions. For example, you can only skip 6 songs per hour per station, and you are limited to 12 total skips per day. The NA7004 Pandora interface also allows you to use the Thumbs Up / Down feature on any track and you can bookmark a track and view the bookmarks at Pandora.com. Pandora does offer an upgraded service called Pandora One which is fee based and offers no advertisements and streams at 192 kbps. Unfortunately, Pandora does not support Pandora One on standalone devices such as the NA7004 at this time.
In addition to Pandora radio, the NA7004 supports Napster and Rhapsody. Napster is a monthly subscription based music distribution service and Rhapsody is a subscription based broadcast service. I did not explore the interface for either service with the NA7004.
Now that we’ve covered the internet services on the NA7004, let’s move on to the USB capabilities. On the front of the NA7004 is a USB input which accepts a standard Type A USB connector. If you plug an iPod or iPhone into this connection, and select the iPod/USB input on the NA7004, you now have a very nice dock for your favorite Apple device. The NA7004 comes with a small plastic stand which you can use to support the iPod. When used as an iPod dock, the NA7004 can operate in one of two modes. In “Direct mode”, all song information is displayed on the iPod itself. In “Remote mode”, the iPod information is shown on the display of the NA7004. This connection also allowed me to play ALAC (Apple Lossless Audio Codec) to the NA7004.
If you connect a USB drive to the front USB input on the NA7004, the front display of the NA7004 will allow you to navigate the file and folder structure on the USB device. To play a song, you simply have to press the Enter button on the remote or on the front panel of the NA7004 and the song begins to play. The Display button allows you to see the artist name, album name, and the file type and bitrate of the media that you are currently playing. I had no trouble playing MP3, Windows Media Audio 9.2 and FLAC encoded media. I was able to play MPEG-4 AAC files with variable bit rate, average bit rate, and constant bit rate encodings. I was not able to play WMA 9.2 Lossless media directly. This is a limitation of the internal decoder in the NA7004, but there are at least three ways around this limitation as we’ll see in a moment.
On the back of the NA7004 is another USB input which accepts a standard type B USB connector. I connected a laptop running Windows 7 to this rear USB input and selected the “Digital In USB” input on the NA7004. A Windows dialog box appeared informing me that my device was ready to use.
In order to use a USB device with the Windows Media Player, you have to change the application’s audio device. I opened up the Windows Media Player application and opened the “Options” dialog and selected the “Devices” tab.
Select “Speakers” and press the “Properties” button, and you finally see the “Speaker Properties” dialog.
Select “SPDIF Interface (USB Audio Device)” as your audio device and you will finally be ready to enjoy music from Windows 7 via the USB output. While the Windows Media Player setup interface was far from straightforward, this configuration rewarded me with the ability to play WMA 9.2 Lossless media to the NA7004.
Home Network Connectivity
If you select the “Music Server” input on the NA7004, the player will display a list of the DLNA compliant music servers on your home network. Simply select a server from the list and you will be able to browse by album, artist, etc. and play your selections with the NA7004.
In this configuration, the NA7004 is acting as a Digital Media Player. I tested the NA7004 using the Asset UPnP / DLNA server from Illustrate as well as with TwonkyServer from PacketVideo. The NA7004 worked well with both servers and had no trouble playing MP3, WMA and 24 bit 88.2 kHz as well as 96 kHz FLAC format files. Using the “Music Server” input also allows you to take advantage of WMA 9.2 Lossless media. The WMA 9.2 Lossless format is transcoded to PCM by your server software and sent to the NA7004.
If you have Microsoft Windows 7, then you can make use of the Play To functionality. This is by far one of the simplest ways to get music to your NA7004. Simply find a directory or individual music file, right click, and select “Play To” from the menu.
In this example, I right-clicked on the Raising Sand album directory, and Windows 7 automatically added the album contents to a playlist.
If you enabled “Network Standby” on the NA7004, then the NA7004 will automatically turn on when it receives the Play To request from Windows. Simply turn on your stereo, and you will be enjoying music from your Windows 7 environment. The Play To functionality automatically handles WMA 9.2 Lossless media as well.
Not being one to take sides, the NA7004 also supports Apple’s AirPlay functionality. As we discussed earlier, you have to purchase a separate upgrade package from Marantz in order to enable AirPlay. To make use of AirPlay within iTunes, you just need to look in the lower right hand corner of your iTunes application.
Selecting the AirPlay icon brings up the following dialog:
Simply select the NA7004 and your iTunes content will be streamed to your NA7004. Another benefit of AirPlay is that you can stream content to multiple destinations.
You can play content to your local computer and to the NA7004 simultaneously. If you have multiple AirPlay enabled devices in your home, you can stream simultaneously to those devices as well. This same functionality works with the iPad and later generation iPhones and advanced iPods. AirPlay allows you to directly stream content stored on any of those devices to the NA7004. This was an extremely enjoyable feature and I loved streaming content directly from my iPhone to the NA7004 without the need to turn on my PC.
Thanks to the networking connectivity offered by the NA7004, there are multiple options to control the player. The first method is with the Wizz App.
The first page of this application lets you see the current input, power on/off the NA7004 and select from a quick list of your top six favorite inputs. If you need access to a less frequently used input, simply press “Source Select” and you will get a complete list of all the inputs on the NA7004. The “Favorite” input is missing from the list and must be selected from the remote or the front panel on the player. The “Digital Out” button lets you toggle the player’s digital output on or off. The same goes for the “M-DAX” button which cycles the M-DAX filter through its various values. The small icon in the lower right corner brings up a small set of transport buttons.
My biggest complaint with page one of the Wizz App was the M-DAX button. Since it is at the bottom of the page, it was really easy to accidentally hit the button when moving to another page in the Wizz App. This had the undesired result of turning on M-DAX when I didn’t want the filter engaged. I quickly learned to swipe my finger over the top part of the screen to avoid the problem. The “Play/Pause” would also not work consistently.
The second page of the Wizz App was context sensitive based on the selected input on the NA7004. For example, if you selected “Music Server” and were browsing album content, the Wizz App would display the album hierarchy returned from the current DLNA server.
The solid white line indicated the current position in the list which was “[All Albums]” in this example. The most aggravating aspect of Wizz App is that it does not support simple scrolling. While “A-F” is displayed, you have to move your finger up the page to cause the application to get the next batch of letters which are “G-M”. Repeat this process again to get “N-T” and once more to get “U-Z” and “0-9”. Needless to say, this gets really old very quickly. This same type of batch oriented scrolling is common throughout Wizz App.
The last page of Wizz App displays the currently playing song, the artist name, and a very small album art graphic. In this example, I was playing one of Secrets greatest hits - the “60 Hz and 7 kHz IMD” test track.
There is a lot of wasted space on this page and I really wish the album art was bigger. The front panel on the NA7004 will show the same information and is generally much easier to read.
Despite the limitations in some areas, the Wizz App proved very handy in controlling the NA7004. I communicated my feedback to Marantz, and I hope to see some of these usability issues addressed in future versions of Wizz App.
There are a couple of other control applications for the NA7004 that I would like to mention. The first is the Apple Remote application available for free at the App Store. If you have an Apple iPod, iPhone or iPad, then you should definitely be using the Remote application to control any iTunes library or Apple TV on your network. Since you can stream from iTunes to the NA7004 using AirPlay, the Remote application becomes one of the best free remotes available for the NA7004.
Since the NA7004 is also a DLNA Renderer, you can control the player from other applications that support DLNA. For example, I used Asset Control from Illustrate and TwonkyManager from PacketVideo to directly control the NA7004. I selected songs, servers, and playlists, and the NA7004 played my music.
Despite all of the underlying complexities of networking, file formats, and different vendors and software, I was really amazed at just how well the NA7004 stood up to the challenges. If there was any really weak area, it was simply in the device’s ability to gracefully handle simultaneous access from multiple control points. For example, I was playing music from my computer’s DLNA server (Asset UPnP) and then decided to try using the “Play To” functionality from Windows 7. I was controlling the music from Wizz App. On my computer, I highlighted some music, right clicked, and hit “Play To Marantz: [NA7004]”. The NA7004 seemed to just lose its mind. The display on the NA7004 continued to show the last song that it was playing from the prior DLNA server session. It would then intermittently show “Server Error”. Simply reselecting the “Music Server” input corrected the problem, but this sort of thing could be frustrating to casual users. My best advice is to simply stop playing the current “Music Server” source before selecting a new server. When I did that, the NA7004 seemed to behave very well. I should also note that the AirPlay implementation performed the best in this regard and warned that the NA7004 was in use if I accessed the player from multiple Apple sources concurrently.
Overall, I was very impressed with the sound quality of the NA7004. Given all the inputs and the varied formats, this player did an excellent job rendering music. Internet music at low bit rates sounded really bad at times. Playing low resolution MP3 files was dull and unsatisfying. While the player’s M-DAX filter attempted to smooth out the sound on poor content, I generally found that it did not really enhance the sound quality in a substantial way for my listening tastes. The best way to make the NA7004 shine was to give it a high quality source. Streaming CD quality music from some of my favorites artists like Diana Krall, Melody Gardot, Michael Bublé and Madeleine Peyroux was a totally enjoyable experience. Vocals were well defined. The soundstage sounded very natural. I was able to just sit back and enjoy FLAC files streaming over my network courtesy of DLNA. The best part of the experience was not shuffling discs into a CD player.
While listening to CD content was very satisfying, perhaps the best thing about the NA7004 is that it also lets you explore and enjoy high resolution audio.
Listening to the 24 bit 96 kHz sampler tracks from HDTracks and the 24 bit 96 kHz studio master of Dawn Langstroth’s Highwire album took the NA7004 to a whole new level. I was now listening to SACD quality music with all of its depth, detail, and engaging realism from a high resolution audio file streaming over my network. I was thrilled that I could enjoy music with such exceptional quality on the NA7004.
On the Bench
The bench tests for the NA7004 were done with our standard set of CD quality, 16 bit, 44.1 kHz test tones converted to various formats including FLAC, ALAC (Apple Lossless Audio Codec), WMA 9.2 Lossless, WMA 9.2 and MP3 at 128 kbps. The tests were done using SpectraPLUS software measuring the analog output of the NA7004.
At 1 kHz, THD+N for CD (FLAC encoding) played from a USB stick connected to the front iPod/USB input was 0.00108%.
At 1 kHz, THD+N for CD (FLAC encoding) streamed via DLNA using the Asset UPnP server was 0.00110%.
At 1 kHz, THD+N for CD (ALAC encoding) played from an iPhone connected to the front iPod/USB input was 0.00113%.
Here’s the exact same test with the M-DAX filter set to “Low”. At 1 kHz, THD+N for CD (ALAC encoding) played from an iPhone connected to the front iPod/USB input was now 0.00292%. We also have a harmonic at 2 kHz and the peak at 3 kHz is now slightly higher.
At 1 kHz, THD+N for CD (ALAC encoding) streamed from an iPhone via AirPlay was 0.07823%. I was very surprised that the results were not similar to my findings when playing the ALAC encoded file from the iPhone via the iPod/USB input. The AirPlay results fluctuated during my bench tests. The average results are what you see below.
Here is a quick snapshot of a couple random samples taken from the same AirPlay test. Note the significant difference in THD+N which is now just 0.00126%. The noise floor is also where it belongs. These results were consistent across all the tests involving AirPlay. I reported the AirPlay bench results to Marantz and will let you know if I get a response to the issue. Despite the bench results, listening to music encoded with ALAC streamed via AirPlay sounded great.
At 1 kHz, THD+N for CD (ALAC encoding) streamed from iTunes via AirPlay was 0.03156%.
At 1 kHz, THD+N for CD (WMA 9.2 Lossless encoding) played from the Windows Media Player from a Windows 7 laptop via the rear USB input on the NA7004 was 0.00196%.
At 1 kHz, THD+N for CD (WMA 9.2 encoding) played from a USB stick connected to the front iPod/USB input was 0.19855%. This result should put to rest any notions of using the WMA 9.2 lossy format.
At 1 kHz, THD+N for CD (MP3 128 kbps encoding) played from a USB stick connected to the front iPod/USB input was 0.00275%. While I wouldn’t listen to it for critical listening, I was really impressed with how well the typical MP3 encoding performed on this test compared to the previous WMA 9.2 lossy results.
Here are the results for 19 kHz, 20 kHz combined test frequencies for CD (FLAC encoding) played from a USB stick connected to the front iPod/USB input. There is no visible B-A peak at 1 kHz.
Here are the results for 19 kHz, 20 kHz combined test frequencies for CD (FLAC encoding) streamed via DLNA using the Asset UPnP server. There is again no visible B-A peak at 1 kHz.
Here are the results for 19 kHz, 20 kHz combined test frequencies for CD (ALAC encoding) played from an iPhone connected to the front iPod/USB input. There is no visible B-A peak at 1 kHz, but we do see some additional peaks at -100 dBV on either side of the fundamentals.
Here are the results for 19 kHz, 20 kHz combined test frequencies for CD (ALAC encoding) streamed from an iPhone via AirPlay.
Here are the results for 19 kHz, 20 kHz combined test frequencies CD (ALAC encoding) streamed from iTunes via AirPlay.
Here are the results for 19 kHz, 20 kHz combined test frequencies CD (WMA 9.2 Lossless encoding) played from the Windows Media Player from a Windows 7 laptop via the rear USB input on the NA7004. There is no visible B-A peak at 1 kHz.
Here are the results for 19 kHz, 20 kHz combined test frequencies CD (WMA 9.2 encoding) played from a USB stick connected to the front iPod/USB input. There is no visible B-A peak at 1 kHz.
Here’s the exact same test with the M-DAX filter set to “Low”. Notice that the filter is having a hard time understanding what to do with the test signal and is adding a lot of noise to the output.
In case you were wondering, there is no graph for the 19 kHz, 20 kHz combined test frequencies with MP3 128 kbps encoding since those high frequency signals are discarded by the MP3 encoder.
The IMD measurement for CD (FLAC encoding) played from a USB stick connected to the front iPod/USB input was 0.0006% which was excellent.
The IMD measurement for CD (FLAC encoding) streamed via DLNA using the Asset UPnP server was 0.0010%.
The IMD measurement for CD (ALAC encoding) played from an iPhone connected to the front iPod/USB input was 0.0006%.
The IMD measurement for CD (ALAC encoding) streamed from an iPhone via AirPlay was 0.2280%.
The IMD measurement for CD (ALAC encoding) streamed from iTunes via AirPlay was 0.0915%.
The IMD measurement for CD (WMA 9.2 Lossless encoding) played from the Windows Media Player from a Windows 7 laptop via the rear USB input on the NA7004 was 0.0011%.
The IMD measurement for CD (WMA 9.2 encoding) played from a USB stick connected to the front iPod/USB input was 0.0875%.
The IMD measurement for CD (MP3 128 kbps encoding) played from a USB stick connected to the front iPod/USB input was 0.0012%.
Based on these results, I would rank the file format performance on the NA7004 from best to worst in this order: FLAC, WMA 9.2 Lossless, ALAC via USB, MP3, ALAC via AirPlay, and finally WMA 9.2.
For their first take on a dedicated network audio player, Marantz has done an amazing job of doing things well. The sheer convenience of the player combined with the quality and performance that the NA7004 delivers with the FLAC format, including support for 24 bit 96 kHz content, is impressive. I appreciated how easy it is to listen to music from around the world and to enjoy music from my computer and iPhone. I also appreciate that Marantz is not platform- or brand-specific. Thanks to standards like DLNA, products like the NA7004 can be controlled and integrated into a wide range of configurations. While the integration is not without its occasional problem, the fact that the NA7004 does so much so well is a sign that these standards are maturing. I hope Marantz continues to offer software updates and new features to the NA7004. If you are looking for a network audio player, by all means give the NA7004 an audition.