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Srajan Ebaen
Financial Interests: click here
Source: Ancient Audio Lektor Prime, Raysonic Audio CD228, Apple iMac 1TB with AIFF files up to 24/192, Weiss DAC2, iPod Classic 160GB, Sieben Technology dock, Onkyo ND-S1 digital-direct iPod dock (x 2), Burson Audio HA160D as DAC
Preamp/Integrated: Esoteric C-03 (transistor), Bent Audio Tap-X (AVC passive), ModWright DM 36.5 (tube), ModWright LS100
Amplifier: FirstWatt F5 & J2, ModWright KWA-100 SE, Trafomatic Audio Kaivalya, Octave Audio MRE-130 with SSB, Yamamoto A-09S
Speakers: ASI Tango R, Zu Essence, Boenicke SLS
Headphones: ALO Audio recabled Audez'e LCD-2, Sennheiser HD800, beyerdynamic T1 and AKG K-702; stock audio-technica W5000; stock Grado PS-1000; HifiMan HE5LE with optional silver wiring and grill mod
Headphone amps: Trafomatic Audio Head One; Woo Audio Model 5; Burson Audio HA-160; Meier Audio Corda Concerto
Cables: Complete loom of ASI Liveline, Furutech GT2 and WireWorld Starlight USB A-to-mini-B cables [on loan], LaCie and Entreq Firewire 800 cables, Black Cat Cable Veloce S/PDIF cable [on loan]
Stands: 2 x ASI HeartSong 3-tier, 2 x ASI HeartSong amp stand
Powerline conditioning: 1 x Walker Audio Velocitor S, 1 x Furutech RTP-6
Sundry accessories: Extensive use of Acoustic System Resonators, noise filters and phase inverters, Advanced Acoustics Orbis Wall & Corner units
Room size: 5m x 11.5m W x D, 2.6m ceiling with exposed wooden cross beams every 60cm, plaster over brick walls, suspended wood floor with Tatami-type throw rugs. The listening space opens into the second storey via a staircase and the kitchen/dining room are behind the main listening chair. The latter is thus positioned in the middle of this open floor plan without the usual nearby back wall.
Review Component Retail: $129

iMac with Pure Music in memory play mode of Jamshied Sharifi's One album, concurrent iPod update sync in background

Have you played fence sitter on Pure Music as a sonic upgrade to iTunes and an automatic sample-rate switcher for McIntosh machines? If so, the following screen captures might get you off—the fence—by seeing exactly what the graphic user interface looks like and how the main features are accessed.

I bought Amarra 2 and ran with it for six indecisive months. Then I upgraded to Amarra 2.1 still feeling strangely noncommittal. But a day after I installed Channel D's rather more affordable and altogether nicer interface and experienced its superior memory play feature, I permanently removed Amarra from my OSX dock. When you enable hybrid memory play in Pure Music Preferences--->Music Server Settings--->Basic, memory play begins to stream your selected album or playlist almost immediately whilst the buffer gets fully loaded. Gapless tracks in buffer mode play back truly gapless.

Also, PureMusic does not operate iTunes in 'ghost mode', i.e. in the background but muted. Pure Music embeds itself deeper in the host's OS. It thus does not play the same track simultaneously in iTunes to allow instant toggles back and forth as does Amarra.

As the opening screen capture of my iMac shows, Pure Music adds itself to the iTunes display on the left edge. The upper bar with the ticker-tape title, metering, dynamic range indicator and such can be turned off; have only selected items show; or it can be docked in a different location. If enabled, it will give visual confirmation of the played-back sample rate and confirm whether you play from disc or memory buffer.

The main (left) bar can be set to 'basic' or 'advanced' modes; absolute polarity can be inverted with a mouse click; the 64-bit digital volume slider can be engaged or bypassed by being set to 0 attenuation; and various sub menus can be accessed directly rather than from the Pure Music tool bar on the top.

Apple's remote control works even in memory for play/pause and last/next without having to launch a separate interface. Changing output devices while Pure Music is running—say from my Weiss Firewire DAC to Burson's USB converter—is done from the Advanced Audio Setup --->Device Selection menu after which Pure Music quickly relaunches itself to make the switch. There's no need to manually power it down.

As the subsequent screen captures show, the metering display has a surprising number of options; the Audio Plug-Ins menu can insert equalization such as Spatial Computer currently does with Apple's AUGraphicEqualizer; volume control dithering can be shaped at higher rates; sample rate switching can be confirmed in multiple ways from a beep to a verbal prompt over your computer or main speakers at a user-defined volume; and more.

Clicking the background of the Pure Music display fields anywhere instantly brings up the Pure Music tool bar over the iTunes tool bar. Here you can access Pure Music's drop-down windows.

It's all very self-explanatory even for way-late Mac adopters who wouldn't know OSX from SOX and bought a McIntosh purely to act as a reliable music-server platform (that would be me).

Here is the Advanced Audio Setup window opened to Device Selection to show my Burson Audio HA160D selected (it's simply identified as USB Audio DAC). If you clicked on the sample rate window, you'd see possible selection up to 96kHz as that's the machine's current limit.

The Audio Plug-Ins window allows for the virtual insertion of 'black boxes' i.e. DSP software like equalizers, vacuum tube emulators and such.

Here we see balance, mono and channel inversion options as well as various modes for volume control dithering.

Here one goes to enable gapless playback and hybrid mode for memory play and decides how sample rate changes should be announced if at all. The blue/red Pure Music overlay was pasted in from a different window. It simply shows the software version I ran when these screen captures were taken.

Here we are at various upsampling options and iTouch/iPhone/iPad remote app settings.

Even more options.

Registration logs itself very straightforward in this window. If you selected automatic updates, you're assured to always be running Channel D's latest version.

Of the two Mac-centric music-player software programs—Amarra and Pure Music—not only is Channel D's cheaper, I firmly think it's the superior and better written program. Having interfaced with Channel D creator Rob Robinson via email and telephone, I can also vouch for his hands-on approach and commitment to continuous improvements. When I pointed out that at least reviewers—who ought to make up a truly minute fraction of his clientele—might want to regularly A/B between DACs whilst Pure Music was running, he admitted to never having thought that anyone would want to do that but that this functionality could readily be added.

Two weeks later it had been in version 1.7.1. How was that for customer service?


I'd run by Rob another user scenario that I wished was supported. He patiently spent three emails pounding into my thick skull that it already was. Say you're in a PM listening session of a favorite artist. Suddenly the thought strikes to check in the iTunes stores whether there's anything new from this performer (this happens to me a lot). Say there is. You open the new album in the iTunes store and click on the first track to presample your allotted 30 seconds. Except no sound. How to switch back into iTunes without shutting down Pure Music?

Less is More mode is the ticket. Simply pull down the music server options and select it there.

That's how it'll look. Read the text in the gray field, then hit OK. You might also want to tick off the 'don't show again' field.

Once the instructions disappear, you're left with this. The Pure Music bars have disappeared as well—hence the now visible green background on the left and top—and the Less is More control window has parked itself in that exact spot. As you see, it just covers up the 'play' fields of the iTunes store's track listing for this album.

Since the Less is More window doesn't move—it turns out it does if you put your cursor right on the top edge, then drag it where you want it—simply move the iTunes display to the right like so. Presto, all your compressed presample options are at your disposal to decide whether the new album is worth downloading or not. When you're done and want to revert to the regular PM display, simply click X in the upper left-hand corner of Less is More.

As Rob explained for this toggling between iTunes and Pure Music, Amarra's "Ghost Mode is entirely a different thing and not similar to Less is More. Ghost Mode is still connected to iTunes. Less is More isn't. The regular iTunes UI interaction mode of Pure Music is much better than Ghost Mode which is always causing iTunes to communicate with/send RF energy to the Remote App on an iDevice - besides the other problem of wastefully playing a file twice just to play it once. Ghost Mode also has a flaw in Amarra's (2.1) cache mode. The whole point of memory play is to keep the hard disk from being accessed during playback. That's impossible if iTunes is also playing the file in the background (reading from disk). So when iTunes is active and playing (Ghost Mode) there is no real point to using the cache mode."

In conclusion, Pure Music is affordable and constantly being fine-tuned by incorporating user feedback. Creator Rob Robinson is astonishingly responsive to that. And key for audiophiles is that particularly in Memory Play mode Pure Music becomes a very significant sonic improvement over iTunes whilst leaving all of Apple's slick interactive functionality intact. What more could one ask for? Well, I'm certain Rob will figure this out as time goes on and add features and improvements without ever being prompted. That's the epitome of software-based user happiness, isn't it?

One performance difference between PM1.7 and 1.7.1. for example was "significantly improved efficiency of memory play. Now one can load twice the duration of Redbook CD tracks and 25% more 24-bit audio. Maximum size of a single CD format track that can be loaded with Memory Play is now 3 hours provided enough RAM is available. This also has beneficial effects on performance since memory fetches during playback for the same track(s) are greatly reduced compared to earlier versions..." Did I mention that Pure Music supports Flac playback? And that running the software puts 1/10th the load on the operating system than Amarra? Having paid for the latter only to no longer use it did waste money but sometimes that's part of the learning curve. Perhaps the above will encourage you to save a few bills...

PureMusic website