Support Report: Using UA Plug-Ins in Digidesign ProTools Systems
By Mike Barnes

This article summarizes the facts about the availability and usability of UA's TDM plug-ins and UAD-1 plugs in ProTools systems from UA.

Where does UA stand on TDM?
Our TDM position can be summarized as follows
  1. As of April 1, 2006, the UA TDM Quadpak is discontinued as a physical retail product.

  2. As of May 1st, we discontinued online sales of TDM plug-ins

  3. UA is not developing additional TDM plugs at this stage. We are instead focusing our efforts on UAD development in AU, VST and RTAS formats (RTAS via the FXpansion VST-RTAS adapter). We are not planning any maintenance updates to the existing TDM plug-ins

    There are a number of business and technical reasons for this. Our core expertise is in the non-partitioned, floating-point DSP used in the UAD-1, whereas Digidesign TDM is a fixed-point, multi-DSP system- a completely different programming challenge. Since our UAD cards run seamlessly inside TDM systems using the FXpansion VST to RTAS adapter, it doesn't make sense to spend the engineering resources to port UA plug-ins to the native TDM format.

  4. We encourage Digidesign ProTools HD/LE customers who want access to the widest range of UA plugs to purchase a UAD-1 with the free FXpansion VST-RTAS adapter or the v2 VST-RTAS adapter available from, which allows the UAD-1 to integrate with both ProTools LE and HD.

  5. The good news for existing TDM users is UA is offering a generous UAD X-grade plan.

The TDM to UAD X-grade plan

  1. Buy any version of the UAD-1/UAD-1e card and get all your existing UA TDM plug-ins that you purchased for iLok transferred FREE to your new UAD-1/1e account.

  2. As a loyal UA customer, your X-grade includes:
    1. One FREE UAD plug-in of your choice up to $199 value PLUS
    2. a UAD$100 voucher to use at

  3. “New” RTAS Plug-In versions will be enabled via V2.x UAD VST-RTAS adapter by FXpansion and are fully-compatible with ProTools 7.x on Mac & PC.

I'm interested in this, but what's the real story of RTAS and UAD-1?
The UAD-1 can and does work well in both ProTools HD and LE environments using the FXpansion VST-RTAS adapter. All current UAD-1s ship with a free version of this adapter.

If you have any questions or concerns about how this all works with the UAD-1, please call our helpful UA support staff (some of whom are actually running this system!) toll-free in the U.S. on 877-MY-UAUDIO.

All technical questions relating specifically to Digidesign hardware and software should be referred to their technical support group: 650-731-6100 (8 a.m.-5 p.m. PST Mon.-Thurs., 8 a.m.-4 p.m. Fri.).

All technical support for the FXpansion VST-RTAS adapter is provided by Fxpansion, which is a UK-based company.

Can I use a UAD-1 with both ProTools HD or LE?
Yes. All you need is a free PCI slot in Mac or PC and the
FXpansion VST-RTAS Adapter, a special version of which comes FREE with all new UAD-1 cards.

Does the UAD-1/Fxpansion combo work with PT 7?
Yes, using version 2 of the FXpansion VST to RTAS adapter. UA's free UAD version will ship in Q3.

How does the UAD-1 actually integrate into ProTools?
The UAD-1 plugs use a
software "wrapper" or adapter to convert them from Steinberg's open VST format to Digidesign's proprietary RTAS format. As far as ProTools is concerned, these plugs behave exactly like any other RTAS plug-in except that the resources are being run on the UAD DSP card.

Do ProTools HD and LE have automatic delay compensation (ADC)?
The ADC feature is provided by the host DAW application, not the DSP card. Only ProTools HD provides full automatic delay compensation, and in ProTools HD, delay compensation uses some of the HD DSP. The UAD-1 plugs can be fully delay compensated in ProTools HD. However, there is a trade-off between VST-RTAS adapter buffer size and DSP used for compensation.

Sweetwater has an
excellent article on the UAD-1 with Pro Tools HD and delay compensation.

ProTools LE has no automatic delay compensation, so delay compensation has to be done manually on each track or plug-in. There are a number of different ways to do this, and we detail all of them in a series of
Support Report articles such as last month's.

I'm confused. What's the difference between TDM, RTAS and HTDM, and what plug-in format works on what kind of ProTools system?
Practically speaking, ProTools LE users use only RTAS (Real Time Audio Suite) plug-ins (such as with M-Box, M-Box2, 001, 002, or M-Powered hardware), whereas ProTools HD users can potentially use all three types of plug-in. TDM (Time Division Multiplexing) plug-ins run only on Digidesign's fixed-point, Motorola 56k DSP hardware (e.g., Mix or HD systems). HTDM refers to Host Time Division Multiplexing. UA provides a
FAQ about RTAS; Digidesign also provides a FAQ on all these issues.

Questions or comments on this article?