Rocky Mountain Audiofest 2008 Continued

I was lucky enough to go to RMAF. After attending 3 digital seminars and talking to lots of folks, I was still confused about how I could play high res audio through iTunes-Apple TV. Then I went into the room with Amarra. I entered the room to listen to the Harbeth speakers and DNM electronics. When I sat down I saw the sign, "You are NOT listening to iTunes". So after being really impressed with the sound (way too many rooms had $50k -$100k or more of really bad sounding systems; probably due to set up?) I went over and talked with the guy running the system. He showed me a little about Amarra and my heart leaped, this was the answer I had been looking for, for 3 days. Then i found out you needed his hardware and the soft/hardware package was something on the order of $10k. My heart sank, way out of my budget......<br />

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So maybe this is not the right page to ask these questions:<br />

(Keep in mind I am using iMac, Apple TV to feed a Benchmark DAC, If possible I would like to retain the ATV as my source)<br />

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1. If you had to rip your entire library right now, what software would you rip with ( many panelist reffered to Exact Audio Copy).<br />

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2. What file format to save it as (I am using ALC, but FLAC seems to be universal, if I need to down the road can I convert ALC to FLAC?).<br />

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3. How can I play HRX recordings and or 24/96, or 24/177 in iTunes? ( I almost bought an HRX recording, but the lady at Reference did not know how I was going to play it back, so I waited, she said Chris may be able to help) (BTW, the guys from dCS were in line behind me and bought 2 copies, and may be contacting you for help!)<br />

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4. I felt even after seeing all of the new gadgets, the Apple TV is still the hands down coolest interface, I have one, but being an audiophile did I make the wrong choice? Of the other playback software, can any be accessed via Apple TV?<br />

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machinehead - if you are married to iTunes as a lot of folks are, getting good quality out of it is a challenge. This is why Empirical Audio developed the Pace-Car reclocker. It is designed for exactly these types of devices (AirPort Express, AppleTV, Sonos, Squeezebox, Duet, Transporter). Most WiFi devices are limited currently to 16/44.1 though. If you are wanting hi-res, there are only a couple of firewire devices, USB or direct.<br />

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One possibility is to eliminate USB and firewire completely by putting a Mac Mini next to your rack and run Toslink to the Pace-Car reclocker. This will allow you to playback any sample-rate you want. This is what the editor of Positive-Feedback Dave Clark does. Then you can drive the DAC of your choice. Here is Daves account of his journey with computer audio:<br />

http://www.positive-feedback.com/Issue39/ramblings_computer.htm<br />

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For the best possible jitter reduction, you can run I2S interface from the Pace-Car to a DAC. We have had I2S interface for years and use it with Benchmark DAC-1, Northstar, Perpetual Tech. and our own Overdrive DAC.<br />

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Steve N.<br />

Empirical Audio

I've just started using an AppleTV as a music server and I agree the interface is cool. Well after all, Apple literally wrote the book on human interfaces. I do believe the digital output is limited, probably to 48 khz 16bit. I could be wrong as this is difficult for me to determine. I have an Altmann Attraction DAC and when I tried to playback 96khz 24bit files, the DAC would not lock onto that signal. On this DAC you need to flip a few switches to set the incoming sample rate. It locked onto either 48khz or 44.1khz, I can't remember which; but it certainly wasn't 96khz.<br />

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The Altmann DAC is limited to a 16 bit word length; but can handle sample rates up to 192khz.<br />

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If you try to sync Hi-Res files to the AppleTV at anything above 96khz, iTunes will simply tell you the AppleTV cannot handle that file, so it can't be synced.<br />

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The AppleTV will accept 96khz, 24bit files; but I believe it down-samples them on playback to 44.1 or 48khz, so you're not hearing them at full resolution.<br />

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I would like to see an article that compares various devices like this from Apple including the Airport Express and the Mac's themselves, so we could get a grasp on what their respective limitations are regarding digital output.<br />

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The Mac's come with an Application named 'Audio MIDI Setup'. Before playing files back directly from your Mac, this should be used to set the sample rate and word length. The settings available within Audio Midi Setup for sample rate will depend on the output device selected in the System Preferences for sound output and within the Audio Midi Setup application. For example my Macbook Pro's built in output is limited to 96khz 24bit. You will need to set this within Audio Midi Setup before attempting to playback 96khz 24bit files form iTunes or other player software.<br />

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For Higher Resolution files, such as 176.4 or 192, you would need a sound card which supports those bit rates to play back the files at full resolution. You would then probably want to send the digital output of that sound card to a high-end DAC.<br />

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EAC is probably the ultimate ripper, if you're prepared to use it to the full. In most cases though, I feel iTunes, with the "Use error correction when reading audio CD's" preference set to 'on' is probably just fine.<br />

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The format you rip your music from CD to, depends on how you plan to play it back and, of course, that may well change in the future. If you continue to use various Apple Devices you're better off sticking with Apple Lossless, at least for the moment. You can always cross convert between different lossless or uncompressed formats, when necessary using software such as Max. Admittedly, though it does involve a bit of effort.<br />

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For those HRX recordings then; based on my observations, depending on which Mac or PC you have, the built in Sound Card may be able to play them back at full resolution or you may need an external sound card. My Macbook Pro's built-in audio out can handle 96khz 24bit; but nothing above, so I use an RME Fireface 400 external Firewire sound card for higher resolution files.<br />

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Hope it helps,<br />

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geoff<br />

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Thanks Geoff,<br />

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Great information, I did not know that the ATV is limited in sample rate.<br />

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I would be interested if other Apple products such as the Mac Mini have such limits.<br />

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If using a MacMini or MacBook as the server, then do you use Front Row as a remote interface?<br />

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I am really interested in keeping my TV as my on screen display so I can select songs from the couch.<br />

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Thanks again,<br />

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Jeff

The tech who was running the Amarra software also said that the Mac mini will not run the program. <br />

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It doesn't make much sense in that .1 to .3 (Macbook over the Mac mini) more processor speed would make that much difference. If the program is that much of a resource hog then there certainly will be other limitations.

Machinehead – Flac files do not play in iTunes so AIFF or Apple Lossless would be the best options.<br />

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I might be wrong here but I thought EAC was not compatible with Mac’s. As Geoff has stated the iTunes ripper is fine on a Mac when used with error connection.

Hi Jeff,<br />

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Sometimes I use Front Row on my MacBook Pro's. Usually though I want to work on something at the same time as playing music, so AppleTV is still a good solution for me apart from the limited sample rate support.<br />

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I don't know for sure the limits of the other Macs; but I imagine their digital out is probably limited to 96khz 24bit as with the MacBook Pro. For higher sample rates you either need a sound card or a USB DAC that can support them, such as the upgraded Bel Canto.<br />

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geoff

Chris. I can't wait for your review on this, but are you hinting that the Amarra software will NOT be available in it's own right? (This would be an incredible shame) I mean would there be any technical reasons why it wouldn't work with any DAC? AB

Hi AB - At this very second Amarra will not be available as a standalone product. However, I talked to Amarra's creator and President of Sonic Studio, Jonathan Reichbach, at dinner and expressed my thoughts on offering software only as one option. I really hope this comes to fruition. I'll continue to pass along this request from the readers here on computer Audiophile. Jonathan is a really cool guy who knows what he is doing. I can't wait to get my hands on this product!

Here’s another vote for software only package. I wouldn’t be able to afford the hardware and it’s also likely to be even more expansive if it was sold in the UK.<br />

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I see the rumour is Apple might be dropping the firewire connections on the new MacBooks. Will find out more later today. Makes you wonder whether FireWire DACs will be future proof. Having said that I can’t see them dropping it with the Pro computers.

Another vote for the software!

Nice to get to meet you at RMAF, Chris. I would have to go along with everyone else here on Amarra. I suspect they have quite a bit of development time into this software, and making it available separately will be the best way for them to make some money, and for audiophiles to benefit from their work.<br />

Two things I would like to mention regarding the forthcoming PS Audio Ultralink DAC:<br />

1. This DAC is capable of 24/96 playback via USB, and the USB is never converted to SPDIF, but goes straight to I2S, and can bypass the upsampler, if desired, for direct connection to the DAC chips.<br />

2. The DAC is expandable to incorporate the (under development) PS Audio Bridge. Installing the bridge into the DAC makes the DAC a networked player, capable of accessing any music files on the computer network (via Ethernet, up to 24/192). This playback method will take advantage of PS Audio's Digital Lens technology for vanishingly low jitter levels, and will also allow bypass of the upsampler via I2S if desired.

I believe you are correct, EAC is a Windows only app. My interested is because at one seminar at RMAF, it was made clear that scratched CD's will not sound the same once ripped as a "perfect" CD and that EAC was the industry defacto best quality ripper.<br />

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My thoughts were booting to XP in bootcamp, rip all CD's using EAC to AIF files then importing into iTunes through an external HD.<br />

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Another thing I picked up at the show, the tech running the Amarro setup mentioned that files sound better if you rip them using the OS X utility and then drag them into iTunes.<br />

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I guess this would be a good case for doing some A/B listening.<br />

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All very interesting ideas.<br />

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Early adoption of stuff can be fun be real frustrating sometimes!<br />

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Jeff

Hi Barrows - It was good to meet you, Dave, and Paul as well. Thanks for adding the specs above. 24/96 USB straight to I2S and the ability to bypass an upsampler is pretty cool. This really separates these components from the crowd.

Hi there,<br />

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any idea about the PWT availability ?<br />

What about its detailed specifications ?<br />

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Thx,<br />

Elp.

We are still in the final prototype stage with these two products, then we have beta testing, and then production. I suspect that they will be available late winter/early spring. For more information on these there is a fairly active discussion at the PS Audio forums under various topics.