Hello damuehlbauer,
Please try:
- Make certain that you have only a single instance of the Hauptwerk plug-in loaded within your host's project, since it wouldn't normally make sense to have multiple independent pipe organs within a single project, and Hauptwerk doesn't allow multiple simultaneous plug-in instances. (The Hauptwerk user guide covers that in more detail on page 191 in the current v4.2.1 version, including how to use multiple tracks on different MIDI channels for different divisions if desired, whilst sharing a single plug-in instance in Cubase and Logic, as examples.)
- For now, make sure that the ASIO buffer size in Reaper is set to 1024, which is a 'safe' value that shouldn't stress your PC too much, and thus should allow you to squeeze as much polyphony as possible out of it.
- Make sure that the project's sample rate is set to 48 kHz in Reaper (being the value needed for the Paramount 320).
- Temporarily remove any other plug-ins (e.g. reverb/convolution plug-ins) from your Reaper project, except for Hauptwerk, to try to determine whether any other plug-ins were resulting in the PC being over-stressed overall. (Convolution plug-ins in particular can be very CPU-intensive, for example.)
- Check that the following utility reports that your PC is performing properly for real-time low-latency audio: http://www.resplendence.com/latencymon . Leave it running (but without Task Manager being open) for half an hour or so whilst Hauptwerk is running with an organ loaded. LatencyMon needs to report that the PC is performing well enough for real-time audio before the PC will be able to work reliably for Hauptwerk (or any other real-time audio applications) at low latencies.
Does that solve it? If not, please use 'Help | Create a diagnostic file' and send the resulting file to us ( http://www.hauptwerk.com/forms/support/ ) which will allow us to see the exact specification of your PC, and whether your Hauptwerk logs and settings give any clues.