Apple Setup :

Introduction

For an Apple computer there are a few options that work with iTunes as your music player. iTunes itself is a convenient player as not only does this software package come pre-installed with new Apple computers, but it is easy to set up and use, the ripping capabilities are excellent, and the program works exceptionally well with other Apple products such as iPods.

Computer Requirements for Class 1

There are a few minimum requirements that must be met to achieve reliable audio from your system into the Ayre D/A Converter. These requirements are as follows:

Computer Setup

Regardless of whether you've chosen to play back your music collection in Class 1 or Class 2, setting up your Mac to get the best sound is quite simple. Here are the steps:

1. Apply power to your Ayre D/A converter. After applying power, connect the USB cable from the D/A converter to your computer USB port. Click on the “System Preferences” app on your Dock.


Then in the second row, “Hardware”, click on the “Sound” icon.


First choose the “Sound Effects” tab, which controls the various sounds your other programs make (such as the “e-mail notification” sound). Select “Play alerts and sound effects through: Internal Speakers” so that these sounds are not routed through your stereo system.


Then click on the “Output” tab and select the Ayre USB Interface. This will route the sound from iTunes through your stereo system.


2. On the Dock select the “Finder” app.


Select “Places - Applications”, scroll down the list and click on the “Utilities” folder.


Find the “Audio MIDI Setup.app”.


If you are only playing CDs and MP3 files, you can just run this application once. But if you have a mix of standard-resolution and high-resolution audio files with various sample rates, you will need to change the settings more frequently when using iTunes as your player. Simply drag the “Audio MIDI Setup.app” down to your Dock and it will always be handy.


3. Open the “Audio Midi Setup” application and select “Audio Devices”.


For the “Default Output”, select the Ayre USB Interface and this will send the sounds from iTunes to your stereo system.

For the “System Output” choose the “Built-In Output” and this will send system sounds such as a “New Mail Alert” to the built-in system speakers.

There is a drop-down list called “Properties For:”. Select the Ayre USB D/A converter and choose the appropriate sample rate in the “Audio Output” section. Normally this will be “44100.0 Hz” for playback of CD-sourced or MP3 music files.

If you select a sample rate that is different than the sample rate of the music file itself, OS X will perform a sample-rate conversion, and the data sent to the Ayre USB D/A converter will not be bit-perfect. Be sure to set the “Audio Output - Format:” setting to the native sample rate of the music file that you wish to play. You must exit iTunes first for the sample rate change to take effect. Then restart iTunes and play the desired music file.

Some players, such as Amarra, Decibel, or Pure Music offer automatic rate changing to match the recording's sample rate without having to change any settings in Audio MIDI Setup. More information on these players may be found on their respective web pages. Note: If you use a player that features automatic rate switching, it is best to set your the Ayre USB Interface to its maximum sample rate in the Audio MIDI Setup (96 kHz or 192 kHz). This ensures that the maximum rate the player can switch to is not limited by this setting.

Going Beyond 96 kHz

Before you attempt to work with files beyond 96 kHz, please go through the normal setup instructions with your Ayre D/A converter set in Class 1 mode. Make sure that everything is working properly and you are familiar with your system and its software. Only then should you attempt to work with files beyond 96kHz.

Computer Requirements for Class 2 Determining Whether a USB Port is Shared or Unshared

While old or poorly designed USB controller chips can cause problems with Class 2 Audio, please remember that the latest version of Snow Leopard is required to reach speeds of 192 kHz. Since Snow Leopard only runs on Intel-based Apple computers, these are all fairly new machines and generally you should not run into any problems in this regard.

However, there is one cardinal rule—for Class 2 Audio the Ayre USB D/A converter cannot share a USB controller with any other devices.

To ensure that the Ayre USB D/A converter is running on its own dedicated USB controller is largely a matter of trial-and-error. Normally the physical USB port will be connected to a "smart" controller that automatically changes from USB 1.1 (Full Speed) to USB 2.0 (High Speed or "Enhanced), depending on the requirements of the attached peripheral device. However, there will not be a dedicated controller for each port, so sometimes it may be a bit of a trick to find an arrangement whereby the Ayre USB D/A converter has its own dedicated USB controller.

Many Apple computers will already have internal devices (laptop cameras, IR receivers, Bluetooth external devices (mouse, keyboard, iPod dock, hard drive, et cetera) connected. The more devices connected, the more difficult it becomes to ensure that the Ayre USB D/A converter has dedicated access to a High Speed USB controller. Sometimes it will be helpful to disable any unused USB devices to allow more flexible configuration of the necessary devices.

To determine which USB devices are connected to which controllers, go to "Apps - Utilities - System Profiler".

On the left side click on "Hardware - USB". On the right side will be a section labeled "USB Device Tree". With the Ayre USB D/A converter set to "Rsrv B" (Class 2 Audio) and plugged into the computer, the goal is to have the USB device labeled "Ayre USB Interface" as the sole device under a controller labeled "USB High-Speed Bus".

To achieve this you may need to try connecting various combinations of USB devices into the USB ports. Each time you change the connection, you will need to select "View - Refresh" from the Menu Bar at the top of the screen. Should you run out of available USB ports, you may need to purchase a USB port expander (hub). Often these are built into peripheral devices such as keyboards or displays. When using a USB hub, only connect slower Full Speed (USB 1.1) devices through the hub whenever possible.

Do not connect your Ayre USB D/A converter to your computer through a hub, as this may cause dropouts, clicks, or other disruptions. Do not share the controller labeled "USB High-Speed Bus" in the System Profiler with other High Speed devices (external hard disk drives, iPod connectors or docks, et cetera).

Also note that even though you have set up your Ayre D/A converter for use in Class 1, you will have to repeat the setup steps when changing the DAC to Class 2. Even though the DAC is labeled Ayre USB Interface regardless of mode, the two classes are handled as two separate devices by the operating system.

Troubleshooting

Should your Ayre USB D/A converter stop responding, go to "Apps - System - Sound". If the "Ayre USB Interface" is not listed, try "re-booting" the D/A converter by unplugging the USB cable for ten seconds and then reconnecting it. This is a semi-common experience when using an iPod, which is a High Speed device. Unless it has been determined that the iPod connector (or dock) is on a separate USB controller during the setup process, connecting the iPod will "kick off" the Ayre USB D/A converter from the "USB High-Speed Bus". While "re-booting" the Ayre D/A converter will solve the problem temporarily, you will need to reconfigure the USB connections to your computer to avoid future problems.
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