Hello David,
Thanks for the continued interest.
Yes -- to add to Thomas' reply (thanks, Thomas), please first let us know whether any of the meters on that control panel are going into (or nearly into) the red when the distortion occurs.
If the audio-'CPU' meter is sometimes going into the red on that screen when few or no pipes are sounding:
Unfortunately, the manufacturer-supplied drivers for built-in sound outputs in PCs often don't perform well enough for genuine 'pro audio' applications (reliable low-latency, real-time audio use, such as for virtual instruments like Hauptwerk). As a long-term solution, really it's best to look into getting a proper semi-professional/professional audio interface, which is often necessary on PCs in order to get reliable glitch-free audio at low enough latencies, and with sufficient performance, to be usable for playing virtual instrument software such as Hauptwerk in real-time, since professional/semi-professional audio interfaces (meant for recording studio use) are designed specifically for those things.
Sometimes the freeware ASIO4All driver can help to get reliable audio from a PC's built-in sound output:
http://www.asio4all.com/ . Hence you could perhaps try that first, if you're happy with the audio quality from your PC's built-in sound output. If so: download and install the driver, configure it to use your PC's built-in sound output as its output device, reboot the PC, launch Hauptwerk, then select the ASIO4All driver on Hauptwerk's 'General settings | Audio outputs' screen. If that doesn't solve it:
We cover audio and MIDI interfaces here:
https://www.hauptwerk.com/clientuploads/documentation/PDF/HauptwerkPrerequisites.pdfhttps://www.hauptwerk.com/clientuploads/documentation/PDF/HauptwerkBackgroundTechnicalInfoOnComputerHardware.pdfFor example, RME make very high-quality fully-professional audio interfaces, which should be ideal (although they aren't cheap), e.g.:
http://www.rme-audio.de/en/products/fireface_uc.php . (We use RME's interfaces here, and we find them to be excellent, and extremely reliable.)
M-Audio are a popular (but usually reliable) make of semi-professional audio interfaces at a significantly lower price point:
http://www.m-audio.com/products/browse/ ... interfaces . For example, their 'M-Track' series (M-Track II, M-Track Quad, or M-Track Eight) might be suitable candidates to consider. (I haven't tried the M-Track series myself, but I understand that they're popular with Hauptwerk users, and I've used various earlier M-Audio models, which were very reliable and gave good results).
There are also frequent discussions on this section (Audio / MIDI interfacing) of our forum about the advantages and disadvantages people have found with particular makes/models of audio/MIDI interfaces.
Also, to see whether your computer itself is performing well enough to support real-time audio, please download a utility called LatencyMon:
http://www.resplendence.com/downloads (near the bottom of the page). Install and run it, then click the green 'play' arrow button in it and leave it running for half an hour or so. If the PC is performing sufficiently to be able to handle real-time audio it will (still) say '
Your system appears to be suitable for handling real-time audio ...' in green, like the screenshot here:
http://www.resplendence.com/latencymon . If instead it says something in red indicating that the PC appears to have a problem for real-time audio then there is an underlying hardware/driver/low-level problem that needs to he resolved before you would be able to get reliable results from the PC (in which case employing the services of a computer technical expert such as Francois Ratte to try to get your existing PC performing properly:
http://www.hauptwerkconsultant.com/ ... might be the easiest option).
Best regards, Martin.
Hauptwerk software designer/developer, Milan Digital Audio.