Rhodes Chroma Polaris

Hi Paul,

> 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.

Your preference runs the show here - I just wanted to make the option known on the off-chance a groupbuy hadn't been considered.

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

Sure thing - I put that figure up as the amount where I would start to dither over buying a replacement panel. If the price was under $200 I would definitely order one. If it was under $150 I would buy two as extra insurance... If the replacement panel could be produced for under $100 I would order 3-5 of them to stockpile for future repair opportunities.

> 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. 

DX-7, JX-10, JX-8P and others here are just fine with their membrane switches and plastic ribbon harnesses- If treated with respect and kept out of direct sunlight (UV) these should last as long as the rest of the instrument... But as we all know, they don't on Polaris.

>  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. 

Aha. Very plausible theory regarding the green masking - I'm not plastics expert but it certainly makes sense to me.

> 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.

Great news. Thanks again for all your efforts on this front!

Tony

--- In chromapolaris@yahoogroups.com, "Paul D. DeRocco" <pderocco@...> wrote:
>
> > 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@...
>