Universal Audio WebZine
Volume 1, Number 8, November 2003
[UA Universe] [Ask the Doctors] [UAD-1 Feature] [Compression Obsession]
[Support Report] [Dealer Focus] [Digi-Talk] [Analog Dialog] [Featured Promotion]
[Graphic-Rich WebZine]
[Back Issues] [UA Home]

UAD-1 Feature: Upgrading from OS 9 to OS X

Audio Units UAD-1 Plug-Ins Location
As the release of the long-anticipated OS X drivers for the UAD-1 edges closer, users may be wondering, what will the transition be like from OS 9 to OS X? Actually, as far as the UAD-1, it will be quite easy.

Version 3.3 of the UAD-1 drivers (a public beta of which will be available later this month) will support Audio Units (or AU, the plugins standard built into OS X) and VST plugins in its first release. Users of applications that support either format will be able begin work in the application of their choice in OS X.
Since VST is available on OS X and OS 9, Steinberg applications on OS X (such as Nuendo and Cubase) easily recreate sessions from OS 9, with the plugins and their settings intact. At the moment, we are still testing full compatibility in Digital Performer (DP) and Logic. DP on OS 9 uses only MAS plugins, and on OS X, DP is compatible with AU. Fortunately, DP can identify the MAS plugins in a session, and find their AU counterparts in OS X. Logic on OS 9 uses VST plugins, and Logic on OS X can also find their AU counterparts. Presets made with VST UAD-1 plugins in OS 9 can load into AU plugins via our custom preset loader.

VST UAD-1 Plug-Ins Location
As usual with OS X, installation will be a little different. Since a driver needs to be installed to a folder within the System folder, you will need the administrator password.
As expected, OS X does something different with the plugins. Instead of installing plugins to folders inside each application, there is a folder called “Audio” inside the “Library” folder on the root of the hard drive that OS X is installed to. This folder contains subfolders, and among them is the “Plug-Ins” folder. Inside the Plug-Ins folder is a VST folder (where the Powered Plug-Ins folder is installed) and a “Components” folder, where the Audio Units plug-ins are installed (See figures 1 and 2).

ASIO on OS 9 has been replaced by CoreAudio on OS X. CoreAudio works similarly to ASIO, but it is built into OS X, and was created by Apple. Choosing a CoreAudio driver and selecting a buffer size in OS X is very similar to doing the same in ASIO in OS 9. Like OS 9 and ASIO, the latency of the UAD-1 is two times the CoreAudio buffer size. Logic Audio is an exception to this rule; in Logic, the UAD-1 latency is determined by the larger of the process buffer range setting and the CoreAudio buffer size. Since the smallest process buffer range setting corresponds to 512 samples, the minimum UAD-1 latency in Logic is 1024 samples. We are working with Emagic to address this issue.

Because of fundamental differences between OS 9 and OS X, some issues with certain applications have disappeared. For example, there are issues with dual processor machines in OS 9. In Digital Performer, the main processor could be come heavily loaded in sessions that combined host plugins with UAD-1 plugins. Due to certain system restrictions in MAS in OS 9, host based plugins were sometimes blocked from running on the 2nd processor by UAD-1 plugins, and were forced to run on the main processor. This is not an issue in OS X.

ASIO driver window in Logic on OS 9
In Logic Audio on OS 9, a similar issue exists. If you are a Logic user, you might remember the infamous “I/O Helper” workaround for a problem that occurs when you have UAD-1 plugins on audio tracks and on tracks in “live” mode (please see the Support Report section of the webzine for more information). A fix was put in both the UAD-1 v3.2.0 software and Logic v6.1.1 so users would not have to use the I/O Helper trick, but this fix caused the same issue that DP suffered from under OS 9: the main processor becomes loaded well before the 2nd processor. Like DP in OS X, this is not an issue in Logic in OS X.

CoreAudio driver window in Logic on OS X
While the UAD-1 is physically compatible with all the currently shipping models of the G5, some restrictions may apply when used in combination with particular soundcards. We are currently addressing some issues with the UAD-1 software in certain G5 machines. While the initial UAD-1 public beta may not support G5's, we are confident that all issues will be resolved by the official v3.3 release.

From everyone here at Universal Audio, welcome to OS X!

Dave Crane

Questions or comments on this article?