Non rev2 expansion board

[Tugdual]

I had a dream... like DSI leveraging the modularity of the REV2 and offering a 8 voices OB6 expansion card compatible with the rev2... layer A rev 2, layer B ob6. 

[AlainHubert]

That would be quite impossible since the REV2 is a DCO based synth and a the OB6, and/or the Prophet 6, is a VCO synth. There wouldn't be any CV available to control the pitch of the VCOs. Moreover, even if the "expansion board" would be composed of DCOs, the firmware would have to be completely re-written and expanded to take into account the different added board.
I don't think that Sequential would be willing to go to all that trouble.

The same idea was proposed by owners of OB6 and Prophet 6 about exchanging voice cards from one machine to the other, since the basic architecture is very similar from one machine to the other. But even then, DSI replied that it wouldn't be possible because of the incompatibility between the OB6 and P6 voice cards themselves. There are significant Control Voltages differences between the two.

You could, however, build your own modular system (eurorack or 5U format) and add anything you like to it ? ;-)

[Sleep of Reason]

Not only that, but it sounds like the OP has the impression that they come on single boards... Both the OB-6/P6 have discrete boards per voice.

Furthermore, the filter is what gives it most of its character. So it's not like adding OB-6 VCOs would suddenly get you that trademark sound anyhow.

[Razmo]

Another aspect is the UI... it would be completely impossible to edit the P6 board constructively from the UI of a REV2... even worse the other way around.

[AlainHubert]

Indeed.

All that being said, Tugdual has the right to dream...
I've often dreamed of a machine that would combine a Prophet 5, Memorymoog, Oberheim OBX, Jupiter 8 and a Minimoog D in a single box...

[Tugdual]

Indeed.

All that being said, Tugdual has the right to dream...

people loving music are all somehow dreamers