Synthesizer applications may be limited to audio playback in certain sample rates. If Cubase VST is set to a sample rate other than those, the synthesizer application will play back at the wrong pitch. Consult the documentation of the synthesizer application for details.
Play in BackgroundThe “Play in Background” option on the Options menu must be activated for ReWire to work. If not, the communication between the two programs will be lost.
ASIO Drivers
ReWire works well with ASIO drivers. By using the Cubase VST bussing system you can route sounds from the synthesizer application to various outputs on an ASIO compatible audio card.