1. Is Audirvana compatible with Lion and Mountain Lion?

Audirvana fully works under Lion and Mountain Lion.

You may have heard that Apple had removed from Lion the Integer Mode capability that was bringing a strong improvement in sound quality.

Direct Mode, introduced in Audirvana Plus 1.4, completely bypasses CoreAudio, even its low-level layer, and thus reenables the buried Integer Mode, in addition to offer even increased sound quality. And this makes Mountain Lion the best sounding OS X, thanks to 64bit kernel optimizations made by Apple.

2. I get some dropouts with the CPU red light flashing, how come ?

The main reason for this is memory swapping to disk, namely the audio buffer currently playing.

This is due to insufficient memory available for storing the audio buffers. To prevent this situation to occur, you can exit other memory hungry applications (e.g. Safari), and/or reduce the maximum audio buffers size (User Preferences > Audio System)

 3. I get some clicks about 3-10 times per second

You probably have a Mac whose model has been introduced before 2008 end. These models have a limitation in their USB ports power supply that makes a few samples to be set to 0 every ~16,000, and this only in Integer Mode. And this is what you can hear as clicks. To continue to get the benefits of the Integer Mode, the most widely used workaround consists in connecting a powered USB hub between the DAC and the Mac. (With only the DAC connected to it of course).

4. Is there a way to control playback using an iPad/iPhone remote app ?

You can remote control playback using the iPad/iPhone Apple Remote App that controls iTunes. You use the iTunes integrated mode of Audirvana Plus for this. In this mode iTunes acts only as a remote control for A+.

If your files that are not recognized natively by iTunes (e.g. FLAC, Cue Sheets, DSD, …) you can use the “Add Files to iTunes” command in the Audirvana Plus menu to create small proxy files that’ll be catalogued in iTunes and enable playing of all those files using the iPad/iPhone Remote app.

5. On how many computers can I install Audirvana Plus with one license ?

As per the EULA, it is permitted to proceed to “the installation on a second computer owned by you for your exclusive use with the express condition that this second copy is not used simultaneously with the main one”.