Yannis,
I appreciate your comments!
5. The two Prophets seem to be EQed in the low registers - they have this oomph which is absent from the Solaris and the Microwave XT
The research I was part of in the early days of the Korg OASYS showed that there is a issue in the Prophet osc sawtooth in the low registers that sounds&looks like a bit of a sine wave mixed in with it. The older Scope Multimode oscillator module also has this, and Howard S. also recently mentioned this factor. I've asked Klaus to code a version of this approach, so that Solaris can have two types of Multimode oscs (MM1 & MM2). This will, I think, introduce some aliasing in the upper register, though.
6. In the Solaris there is a HF sizzle, this is apparent both in the high and low registers. The oomph is not there from the beginning, compared to the two Prophets. Maybe this is something that can be fixed with some EQ and the HF sizzle with some additional low-pass filtering
Yes, the Solaris examples here are bypassing the filter section, so you are hearing the oscillators 'raw' and direct...and there's no EQ yet. Some of the 'oomph' could be added via EQ, but I think it will also be good to have the 2nd type of Multimode osc (MM2) to gives us a closer result.
John, maybe you need to pay a little more attention to the sound per se. I am not saying that you haven't done that already but in my opinion focusing on great specifications is less important from the sound.
Yes, I know what you mean. We are talking about it always...
Analog oscillators don't have that much energy in the high registers. After a certain point in the spectrum (around 2KHz), they roll-off frequencies. Unfortunately it's not something you can easily emulate with low-pass filtering - the difference is more analogous to white noise and pink noise. Something like a convolution filter at 96 KHz will do the job but as far as I know it's quite computationally intensive.
I saw your comment about this elsewhere here, and it's really a valuable point - but a convolution filter might draw down the polyphony too much. I will ask, though.
regards,
john b.