> From: syntegrator
>
> When it gets closer to a reality, you can set the whole
> system up at groupbuy.com - This is how Andrew Jury and Jed
> Jorgensen handled their Polysix replacement mainboard project
> over in the Polysix group and it worked really well. I ended
> up buying 10 of these PCBS because as more people signed on
> the unit cost kept dropping and as we ordered more the price
> would drop again... :)

I think I prefer to buy a bunch (minimum 25, perhaps 50) on spec, and just
sell them on eBay, since I'll have to be individually package them and
reship them.

> I completely agree with James - My Polaris still has a fully
> functional membrane panel, but I know the Synth Reaper awaits
> this classic unless I can arrange to have a backup membrane
> panel standing by. If such a part were to cost under $250
> that would be a certain purchase for me, but I understand
> that low volume runs could mean it costing more than that.

I doubt they'll cost that much, but that's not based on any actual quotes.

> While I am posting - I take it that the replacement design
> will use ribbons with a plastic formulation that is less
> prone to cracking with age? I have Roland synths from the 80s
> and 90s that use these kind of connectors and none of them
> have aged appreciably so surely the original issue is
> specific to the Polaris and its choice of ribbon connector supplier?

I have no expertise in plastics or chemistry, but my experience is that
membrane switches (other than the top surface) are normally made out of
polyester (Mylar), and this has a pretty much unlimited lifetime. For
instance, the original Chroma membrane panels have exhibited no such
failures. The Polaris panels failed because they were either made out of
something else (exactly what that may be is lost in the files of Fender of
Japan), or because of some interaction between the green masking and the
plastic. I intend to leave the tails unmasked (since silver oxide is
harmless), and to make sure that whoever makes these doesn't use anything
nonstandard. That's about all I can do.

--

Ciao, Paul D. DeRocco
Paul mailto:pderocco@...