Software Type: Music Server Software for Mac OS X
Price: $129.00, upgrade to 1.88a free for current owners
Website: www.channld.com

Pure(r) Music
In March 2010, Channel D released their music server software Pure Music for OSX. Since then, Pure Music has been one of the reference programs I have used to evaluate music, computer hardware, and audio components due to its neutrality and excellent reliable functionality. Version 1.86 had reached a high degree of reliability with a wealth of functions. Gapless track playback and memory play, CoreAudio Device HOG Mode Exclusive Access support, native device nonmixable integer mode for OSX Snow Leopard, automatic sample rate switching, and native DSD streaming for DACs that support DoP are just a very few of the many features available with this program. All of these features beautifully integrate with the iTunes interface for access to one’s music library while using the Pure Music audio playback engine.

Now Rob Robinson of Channel D has released a significant update to Pure Music in version 1.88a with many performance enhancements and new features:

• Corrected playback issue involving 48 kHz tracks and the Fostex DAC (which only supports 96kHz)
• Corrected issue causing distorted audio when playing FLAC files when the hardware doesn’t natively support the file sample rate
• New option to automatically switch to Playthrough mode if an iTunes Internet radio stream is played, and switch back to File mode if a music track file is played
• With the above new Playthrough option enabled, Pure Music will automatically switch to Playthrough mode if an iTunes 128 kbps DRM track is encountered, permitting playing Protected tracks. Will switch back to File mode if a normal music track file is played. Previously, such tracks were skipped
• Improved performance of Playthrough regarding device synchronization
• Improved Reset Window Positions menu command to work more reliably
• Eliminated transient sound that could occur when switching to a normal PCM track from a DSD track playing in PCM mode
• Can play CDs directly without needing to rip to hard drive. CDs can be ejected while playing and a new CD inserted (Memory Play must be enabled), which will automatically play provided preferences are set in iTunes to automatically play inserted CDs
• When files must be downsampled due to audio hardware limitations, will downsample to the next power of two instead of the next lower sample rate
• Eliminated necessity of stopping the audio device when switching between DSD or FLAC tracks, providing improved performance with those formats
• Single-key keyboard commands are now off by default
• Pads the beginning of DSD streamed tracks with “DSD silence” to give DoP - compliant DSD DACs additional time to lock on to the signal before playing music
• Pre-rolls plug-ins to give them time to settle. This avoids a spike in CPU in the IO proc which could happen with convolution or room correction plug-ins when calculating filter coefficients
• Only opens plug-in windows once (on application launch) if Automatically Open Settings is enabled, avoiding annoying re-opening setting windows each time a plug-in was reconfigured
• Improved reliability and execution speed of Add FLAC / DSD... operation
• When album tag is missing in FLAC or DSD file, will substitute name of enclosing folder (previously, used to substitute “Pure Music Bookmark”)
• FLAC and DSD Bookmarks generated more accurately match originals in duration (worked around a quirk of Apple’s APIs that could cause Pure Music’s Bookmark tracks to be 1 to 2 seconds longer)
• Eliminated problem that prevented performing the Add FLAC / DSD... operation on more than one track at a time on computers with one CPU core (G4 processor)
• Now uses alternate form of genre, ‘©gen’ tag for adding genre tag in FLAC bookmark files
• Moved Options (including arcane key modifiers, which have been replaced with check boxes) for FLAC / DSD bookmark generation to a separate modal dialog
• Notifies user with a dialog box message if the original FLAC or DSD media is not available, when playing a Bookmark (instead of simply pausing playback)
• New option to re-add a missing Genre tag using alternate @gen tag without re-creating an existing Bookmark
• New option to keep plug-in windows floating above all other application windows
• Fixed problem preventing the MUTE check box for Bus 1 in the Multichannel tab from working
• For FLAC tracks, shows progress (in percent) of loading track into memory (this is not possible with other file types because of the performance optimizations taken)
• DSD streaming DoP flag now defaults to newer standard 05FA instead of AAAA
• Resynchronizes NetSend communication each time a new track starts playing
• New NetSend menu for activating / disconnecting NetSend
• Support for Nonmixable Integer Stream mode with Lynx Hilo, including multiple output buses

Channel D was going to release version 1.9 with even more features and enhancements, but this has been delayed until later in December. As always, I will be concentrating on the sound quality and stability of this new version.

The Sound of Pure Music (1.88a)
Rob has previously discussed his philosophy of a “steady state” for the CPU and processing in the computer. He feels that this results in an improvement in the sound delivered by Pure Music.

I listened to 1.88a with OSX 10.82 Mountain Lion in an early 2011 MacBook Pro 2.3 GHz Quad Core i7, 16GB RAM, OCZ Vertex 4 256GB for the OS, and external Promise Pegasus Thunderbolt Drive for my music library. A Synergistic Research Thunderbolt Active SE with Enigma tuning circuits connected the Pegasus to the Mac and a Wireworld Platinum Starlight USB cable was used with the Wavelength Audio Silver Crimson/Denominator DAC.

The soundstage of 1.88a has increased in width and depth over the previous version. In fact, it is as good as I’ve heard from any program. What I think makes it very special, is that it is more revealing than 1.86. Just listen to Reference Recordings HRx Exotic Dances from the Opera 176.4/24 and you will understand what I’m talking about. Instruments are rendered in a huge acoustic space with superb definition. The deep bass from the drum has thunderous power while retaining its control and definition. It is the best I have ever heard from this recording. Likewise, the excellent new Channel Classics recording of Mahler Symphony 1 with Ivan Fischer and the Budapest Festival Orchestra 192/24 was reproduced with superlative focus and detail in a natural soundstage that was very engaging.

What I think is going on with 1.88a is that transient rendition or speed has been significantly improved. I am hearing better detail from top to bottom with 1.88a than from the previous version. We talk about pace or the ability to reproduce dynamic sense of rhythm; Pure Music 1.88a does this in a manner that is superior to other programs I have heard. Listen to Paul Simon’s Live in New York 48/24 "Diamonds On The Soles Of Her Shoes". There is less blurring of the instruments and Simon’s voice in the acoustic space. Bass, and particularly the drums are well defined and dynamic sounding. I found myself drawn into this recording in a way I have never been in the past.

As I previously mentioned, bass and particularly the mid bass, are reproduced with excellent definition. No sonic blurring is occurring with the new software. If you like the Weavers Reunion at Carnegie Hall, you will probably like a live recording called Harp: A Time to Sing with Arlo Guthrie, Ronny Gilbert, Pete Seeger, and Holly Near. This live recording is out of print, but I have the original vinyl from 1984 and the CD. Pure Music reproduced Pete Seeger’s voice better than I have ever heard it and as good as my vinyl version. Many of my music programs add mid bass warmth to this recording that obscures the midrange. Pure Music 1.88a got it right.

Gapless playback was tested and it worked flawlessly allowing Pure Music to add the files into memory with perfect playback.

In summary, Pure Music 1.88a is a significant improvement over its predecessor 1.86. In fact, it is now my new reference program. This is not a euphonic program like many out there that add warmth or richness to the music. It is very revealing of detail from top to bottom and the acoustic space of the recording.

Rob Robinson has created something very special in Pure Music 1.88a. I hope that you find it as entertaining and engaging as I have.

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