If you'd like to use Digidesign Pro Tools and Propellerhead Reason together, you should know about reFuse (Mac, $29), an application that translates audio and timing data between the two programs. With reFuse, Pro Tools can record audio directly from Reason as the two programs run in synchronization. Currently, reFuse is available for Mac OS 8.1 through 9.2.2, but not OS X or Windows.
Using ReWire, Reason sends audio and transport-control signals to reFuse, which in turn routes audio to Pro Tools through DirectConnect. MIDI Clock and MIDI Machine Control (MMC), running on IAC busses in OMS 2.3.8, take care of transport linking between Pro Tools and reFuse.
The software has a simple, functional appearance that accommodates its easy-to-use features. After reading reFuse's setup instructions, I quickly had a session up and running on the first try. The programs must be launched in a particular order — Pro Tools, reFuse, and then Reason. Reverse the order to quit the applications.
Depending on your system's capabilities, reFuse can route as many as 16 discrete audio channels. My computer, a Power Mac G4/800 with 768 MB of RAM and a Digidesign 001, could run a 16-channel mix. However, I experienced a few crashes, especially when stopping and starting. You can also record real-time MIDI controller data from Reason on a MIDI track in Pro Tools using a separate IAC bus.
I really like being able to record discrete drum and instrument parts from Reason, simulating a live recording session. I can also use my plug-ins to sweeten Reason's instrument sounds. And now I can record guitar parts while jamming along with Reason tracks. I discovered only one drawback: looping in Reason doesn't work.
The reFuse Web site offers detailed information about program features such as latency offset, tempo linking, and CPU demand. Answers to the questions that I had were already listed in the FAQ section. ReFuse runs on any Mac that can run Pro Tools. reFuse Software; e-mail firstname.lastname@example.org; Web www.refusesoftware.com.