--- In oberheim@yahoogroups.com , "synthy55" <synthy55@...> wrote:

>
>
> recently picked up an ob-sx, it has a switch on the back to flip
> between banks of preset patches, but nothing happens when you flip

the

> switch, maybe you have to press a button as well , i don't have a
> manual, anyone know how to do it
>

I'm not completely sure, but I think the bank select switch is there
for an _optional_ EPROM containing more patches. If you look inside
the OB-SX, you'll probably see an empty EPROM socket somewhere on the
main circuit board.