Pure Music

[earflappin]

Juergen, thanks for the response. For as many people who use the Berkeley I'm surprised to see so little discussion regarding the most optimal interface either here on this forum or on others.

 

Anyway, I'm going to do some experimentation. I know the Antelope DA provides improvements, but it does not reclock the AES. I'm going to get a Black Lion Micro Clock Mk2 to try. Socrates is coming over next week and will bring is Legato so I'll get a chance to hear an async USB/SPDIF interface. Then when Antelope comes out with their Zodiac Plus next month I'll get to hear what a reclocked and noise isolated AES interface sounds like. I'll report back my findings.

 

[coot]

My iPod Touch timing bar does not move when controlling PM. Anyone else notice this?

 

[ted_b]

Rob explains that iTunes is not really being used (as he reminds us it is in Amarra, a waste of CPU in his mind). PV or PM can make iTunes timebar work on the main GUI (set in preferences) but the remote app must look at a different aspect of iTunes and display a static time remaining bar in the iPod/touch (the bar changes to last seen time if song is paused for any reason, but remains static there again). Also, as documented, the play/pause indicator does not change (it works, just doesn't change), again for the same reasons...iTunes is not playing the song...PM/PV is.

 

[bdiament]

I have been told by an acquaintance that Pure Music will play at the word length of the source IF its volume control is left at 0.

 

Can anyone verify this?

(I have not yet downloaded it to demo.)

 

Thanks in advance.

 

Best regards,

Barry

www.soundkeeperrecordings.com

www.barrydiamentaudio.com

 

 

[ted_b]

When using the volume control in iTunes, the volume setting is mapped to a

corresponding volume setting in Pure Music (the iTunes maximum setting is

mapped to 0 dB in Pure Music). iTunes is not controlling the volume, because it

isn't playing the file. With the Monitor setting in Pure Music at 0 dB, the

original audio isn't altered at all: you get direct playthrough via a lossless, 64

bit audio kernel to your high-end DAC.

 

[JR_Audio]

Barry, see my comment above.

 

PM is bit true for 16 and for 24 Bit signals, so when you put in a 16 bit signal, then absolutely the same 16 bit signal gets out.

 

Juergen

 

[bdiament]

I raised the question because of Chris' comment early in this thread, where he suggested that sample rate was changing but word length was not. (I'm not sure how this was tested. I don't believe the HDCD indicator on the Alpha is an accurate way of assessing this -- if indeed that was how the determination was made... I don't know. I prefer an accurate bit meter like the one in SpectraFoo.)

 

To clarify, if I switch between a 16/44 file and a 24/192 file, I want both to play back natively. And I shouldn't have to mess with Audio/MIDI settings.

 

I don't want to pad the 16-bit file with zeros, don't want the 24-bit file truncated and I want the original sampling rate.

 

So, the question is, can Pure Music do this?

 

Best regards,

Barry

www.soundkeeperrecordings.com

www.barrydiamentaudio.com

 

 

[bdiament]

Here's another question for users of Pure Music:

 

If I understand correctly, the app uses iTunes interface and playlists but iTunes is not running (as it is with another app that uses iTunes as a "back end").

 

If this is indeed the case, if a tune is selected in the iTunes window and the user accidentally hits Delete, can the tune be deleted?

 

Can *any* changes be made to the iTunes library when Pure Music is running?

 

Just curious. When my library is fully loaded, I hope to write protect the disk that houses it and so avoid any accidental changes or deletions.

 

Best regards,

Barry

www.soundkeeperrecordings.com

www.barrydiamentaudio.com

 

 

[JR_Audio]

Barry, everything goes out as it goes it. So absolutely the same signal at the output as on the input. (PS: padding with static zeros = zero). Nothing added, nothing lost.

 

Juergen

 

[bdiament]

Hi Jeurgen,

 

I understand padding with zeros is benign but if the source is 16-bits, I do not consider a padded 24-bit file the same as what goes in.

 

Best regards,

Barry

www.soundkeeperrecordings.com

www.barrydiamentaudio.com

 

 

[Lars]

Barry,

 

Why not give Rob a call at Channel D or e-mail him. I'm sure he will be happy to answer your questions.

 

[bdiament]

Hi Lars,

 

Thanks. Good idea.

Done. I await the response to the questions I sent.

 

Best regards,

Barry

www.soundkeeperrecordings.com

www.barrydiamentaudio.com

 

 

[cfmsp]

I received this response today from ChannlD:

 

"Sorry for the delay in responding, generally we respond the same day, if not within a few hours, but we are short staffed because of exhibiting at the AXPONA expo last week, and things are just now getting back to the normal state."

 

In response to my issue that simply quitting Pure Music prevents any iTunes output without a restart:

 

"Have you tried slightly nudging the volume control in iTunes after quitting Pure Music, and then playing iTunes?" So, others with this issue may want to try this recommendation.

 

In response to my issues of loss of itunes-PM synchronization & intermittent stopping of play for no apparent reason:

 

"We are getting reports of occasional synchronization issues similar to those that you have reported. This happens especially when jumping around frequently in a playlist. We are working to correct this problem and appreciate your patience. In our internal testing, if allowed to play through a music library on its own, the test systems have been stepping through tracks continuously for at least several days. Can you be specific about the track format (sample rate, file format), if the tracks are gapless, and if you're using Memory Play (and Hybrid Mode, etc.)?"

 

While I've not had a chance yet to try the suggestions, I wanted to post what was a welcome reply to me.

 

Our patience will likely result in an improved experience with Pure Music, and if Lars' experience is repeated, we may not have to wait long.

 

Clay

 

 

 

[cfmsp]

Couple of comments.

 

Even when deleting files from iTunes, one has to respond actively to an additional prompt to move the file to Trash. The standard delete in iTunes simply deletes the file from the iTunes library, but does not delete the file. Of course, even after the file has been moved to the Trash, it has still not been actually deleted from the disk.

 

Regarding the integration with iTunes - Channld has chosen a less tight level of integration with iTunes than did Sonic with Amarra. Unlike Amarra which attempts to 'integrate' with all iTunes functions, Pure Music only link to iTunes for a limited set of functions. This allows ChannlD less onerous access to the iTunes library / file management, without the headaches of full-on integration.

 

Personally, I never understood why Amarra's integration required the simultaneous playing of songs via iTunes. Now that (I think) I better understand why, and the resulting tradeoffs, I feel that the ChannelD approach is better, given the rather larger processing footprint required by Amarra/iTunes. Of course, at the time Sonic made their decision, it was not as widely accepted that a significant portion of the differences we hear between different computer sources is due to the processing footprint of the music player itself.

 

YMMV, as always,

Clay

 

PS, there are at least two other music players being built - one by Audiofile Engineering, and another of unknown source, but referenced recently on AA by Gordon Rankin. Apparently this new player will eschew any floating point conversions, and will bypass CoreAudio to a greater extent than other programs in existence.

 

 

 

[bdiament]

Hi Clay,

 

Yes, I'm aware of Twilight. Don't know the other one.

Why would anyone perform "floating point conversions" in a player anyway? (I can't think of a good reason.)

 

As to deleting from iTunes, I'll likely just write protect the (separate) hard disk that houses the iTunes library, once I have it all loaded. I hate to think any of the work involved in loading the library would have to be done again, so I want to keep it safe from accidents. (I also have another disk that serves as backup, just in case.)

 

Meanwhile, I'm looking forward to trying out Pure Music this week. The advance word from some colleagues have been very enthusiastic. I'll run it through the Maggie system and see what they tell me.

 

Best regards,

Barry

www.soundkeeperrecordings.com

www.barrydiamentaudio.com

 

 

 

 

[Lars]

So far, Pure Vinyl is the best I've heard of any player. I will install Pure Music this weekend and compare the two for everyone. I suspect that they will sound quite similar.

 

Gordon stated:

 

"The only real reason to use Float32 is for mixing with other applications which gives any Audio Stack and easy way to do that."

 

Amarra, Pure Vinyl (Pure Music), and Twilight are all derived from music editing programs. This may explain the use of floating point conversions.

 

Steve

 

 

 

 

 

[cfmsp]

 

 

"The only real reason to use Float32 is for mixing with other applications which gives any Audio Stack and easy way to do that."

 

I think the more relevant reason for our music playback needs is to support dithered volume control.

 

 

clay

 

[bottlerocket]

"Personally, I never understood why Amarra's ............., given the rather larger processing footprint required by Amarra/iTunes."

 

Try checking your MAC activity monitor comparing Amarra Mini and Itunes to PM and Itunes. Both run Itunes, but PM only uses the database and not the player. However PM uses way more CPU than Amarra - so much so that the combination of Amarra and Itunes playing simultaneously takes less CPU than PM and Itunes. Try it. I am not buying Channel D's "footprint" claim. Once you try the above repeat it with PM running playing from memory. I hit 48% on CPU doing that. Amarra and Itunes together was about 8%.

 

I like PM though. It's a good improvement over PV. Simple and the nasty clicking I was getting with PV is gone. The price is right too.

 

[Lars]

Running hi-rez files in memory with PV I see about 4.5% CPU using a 2.93GHz Core 2 Duo. It is less for Amarra. I have never heard clicking on any PV version. Perhaps this may be related to your computer's resources.

 

[cfmsp]

 

 

"However PM uses way more CPU than Amarra"

 

I remember reading - probably release notes/instructions for PM - a list of features one could turn off to reduce unnecessary (for music playback) processing by Pure Music. As I recall, it was prioritized by the amount of processor reduction. Employing these recommendations might dramatically change your experience of PM.

 

One thing I never liked about PV was the gratuitous (in my opinion) video display, e.g. the spinning vinyl metaphor & the firefly whatever. Thankfully, PM has somewhat less, but even that should be turned off if processing is a concern, and especially so, if you're running headless, as the VNC server also creates quite an unnecessary extra load.

 

YMMV,

Clay

 

[Lars]

Good points Clay. Also, maybe the upsampling was on to hit such a high CPU.

 

[cfmsp]

I believe upsampling is scheduled for a future release of Pure Music.

 

 

getting back to the iTunes integration approaches (of Amarra vs. PV/PM) for a moment, I believe that the downside of ChannlD's approach is that the control synchronization (between iTunes and Pure Music) will likely remain its achilles heel. IOW, it's likely that - with Pure Vinyl/Pure Music - those (like myself) expecting to be-bop around through their iTunes library will be more likely to lose sync between the iTunes and PV/PM apps.

 

ChannlD has this to say about this topic:

 

"Note to audiophiles about the iTunes Music Server Feature:

 

" [Pure Vinyl/Pure Music] provides you with direct access to an ultra high quality music playback engine. However, as with computer software, there is a very, very strong temptation to "test" it by "exercising" the controls, skipping forward, back, etc. repeatedly, trying to provoke hiccups. That is, in essence, using it as a toy, instead of as a tool for serious music listening. (Since critical listening is impossible while rapidly stepping through tracks, etc., that activity is best left to native playback with iTunes, etc., anyway.)

 

When using [Pure Music], envision how you would use a standalone, hardware based CD player (especially one having a memory play feature, which has the same side effect of delaying playback while the CD is loaded into memory). Rather than constantly exercising the remote, just press Play, relax, and experience the superb, crystalline, highest possible quality playback available for your music..."

 

 

While I certainly appreciate the intended 'spirit' of the Channel D comments above, I also happen not to agree with it completely. One of the joys (for me) of computer access to our music libraries is instantaneous access to each and every track. Channel D's "philosophy" assumes that listeners are willing to remain subject to the limitations of the previous generations of technology, i.e. CD / Vinyl playback.

 

In some ways, it's a great example of what we in the software development industry refer to as "calling a bug a feature". It's certainly a preemptive strike against those who might take issue with the rather, shall we say, sensitive nature of the user interface, esp. with respect to maintaining control synchronization with iTunes.

 

I can certainly respect their approach, but I'm hopeful that with Pure Music we will see improvements in this area, as I, for one, don't expect to give up the newly found freedom of easy, instant access to all of my music tracks.

 

As Channel D also says at the end of their notes to audiophiles,

Enjoy,

Clay

 

 

 

 

 

 

 

 

 

 

[Lars]

I have have no problems getting access to my library with Pure Vinyl using Remote with the iPodTouch.

 

 

 

 

 

[Jim L.]

Clay,

I totally agree! I love the sound of PV, but one of the main reasons I got into computer audio was so I could use the shuffle feature which I grew to love using my Ipod. Using shuffle with PV is very frustrating as it loses sync very often and PM works no better! If another reasonably priced alternative comes along that sounds as good and doesn't have this issue, I would quickly change to that! Hopefully PV will finally resolve this issue!! I'm sure with the excellent pricing of PM, many should sell.

 

[Wavelength]

Barry,

 

I understand padding with zeros is benign but if the source is 16-bits, I do not consider a padded 24-bit file the same as what goes in.

 

Juergen is correct in saying that padded 16 to 24 bits is not an issue and zero=zero. A better way to say it is the end analog output would not be any different for 16 bit data padded with zero into 24 bit data or outputting the same signal in it's 16 bit form.

 

Chris, yes you should set the Audio Midi to 24 bits for best results.

 

I don't really know what Rob is doing here but a little insight into Core Audio and such is that most applications use Float32 internally. There is a move to go to Float64 as there is no real way to carry 32 bit integer PCM data bit perfect with Float32.

 

So in most cases a sample at 16 bits is converted to Float32 if nothing touches it then Core Audio will look at the output device see if it needs to resample (hopefully not) and what the bit size is and then convert the Float32 to an integer. When converting a 16 bit sample to an integer 24 it will in a sense pad the sample with zero.

 

I like PM and I do agree it sounds better than Amarra especially with the Memory Mode turned on. I will say that iTunes is still running and still eating up processor and huge amount of virtual and real memory. Running top in the terminal I still find that with Amarra and PM that iTunes takes up about the same resources and processor time. But PM over Amarra is a lot less stressful on the Processor by between 2-6% depending on the speed and resources of the MAC.

 

I did receive another Twilight beta last week. I will load that up and see where that is at in my free (yea right) time.

 

Thanks

Gordon