otto wrote:So what am I missing?
hmmm .. does POLYMOD ring a bell ?
modulating filter with vco (filter fm), vco with vco (crossmod), or pwm with vco is nothing short of KILLER on a Prophet. a trademark sound. that is certainly not a "minor" difference.
indeed there is overlap between Rev3 and OB8, ive noticed this too. but that OB8 can cover "most" of Rev3 i disagree with. for starters, even tho most chips are the same, the circuits are tweaked differently, the gain staging is different and very important, VCAs are different . it all ads up to P5 having a more agressive, punchier dirtier sound. OB8 is somewhat softer, even compared to OBXA. not night n day, but easily noticeable if u have enough long experience with one of them. however, thanks to this, OB8 can go places where P5 rev3 cannot - with nice strings, using separate PWidth for each VCOs, animated brass/pads , adding the page 2 stuff with additional lfos and envs.. i seriously dislike rev3 for soft strings/pads.. just doesnt suit its character.
and OB8's triangle wave, set octaves apart with quik portamento .. mmm. is just too sweet.. that is sorely missed on OBXA.
talking about other Oberheims, one thing i know for sure, OBXA is a more agressive beast than OB8, which can be a bad or a good thing depending what you want or need. and OB8, even with the same CEM3310 chip governing envelopes, is slightly slower. this is well noticed and documented, that there is even a mod on the net to remedy this, but i havent heard how well it works.
bottom line i think its a great synth. if i didnt have a OBXA and P5 already, it certainly be an option. maybe a best buy single vintage poly out there. however, i lust for Xpander, being sonically further apart from these guys. some dislike its sheen and glassiness... i began to like it. it will complement my other polys beautifully.