I have to say that I am not too happy with the sound of the square on the OBX8.
I did a waveform comparison on an oscilloscope with my hardware SEM Pro and new vst OBX from Gforce. The waveform is very similar on SEM Pro and OBX vst, but square of OBX8 is different. I would like to ask if it is possible to modify the shape of the square waveform using software upgrade or is determinated by hardware?
Of course it's clear that the OBX8 oscillators are analog, but the ability to switch between the OBX/OBXa and OB8 shape suggests that this shape can be influenced with digital control.
Owners of the Tom Oberheim SEM and the vintage SEM report that they don't sound the same.
I am highly skeptical of VSTs. I have tried many of them and they do a better job looking like the real thing than sounding like them.
I own vintage FVS, OB-X, and OB-SX. My OB-X8 sounds like the vintage items, it was designed with that specific goal.
If you don't own the vintage stuff, you're comparing apples to oranges.
If you really want to match the OB-X8 to your TO SEM and VST, just use some EQ on the OB-X8 to remove some bass. That's why the top and bottom of the square wave look different - that's what they look like when they are high passed, which attenuates some bass.