U-he is developing a modelled version of the famous Sequential Circuits Pro-One synth. They have an alpha version ready at the moment which they are releasing for free as Researchware. Why? Well, because they want anyone with good ears to help them answer the tricky question: do you want the filter to sucks the juices out of your CPU or do you prefer a compromised version?
You think this is easy? Hell no! You will have a hard time choosing the “most analogue” sounding filter out of those 5 different filter models which are offered in the alpha version of the RePro-1. Check out this voting thread which was created for it at KVR.
Will more CPU cycles make the “most analogue” sound? At the moment 224 people have voted and these votes seem to differ a lot 🙂