Rhodes Chroma Polaris

Would there be enough demand for an electronics manufacturer to make a
run of replacement switch panels for the polaris? Membrane switches
are basically cheap, thats probably why they were used rather than
better components. These could be sold with a set of replacement
ribbon cables, would this be lucrative for some small elec
manufacturer to invest in? How many bad polarises are there, and do
they ALL HAVE THE SAME PROBLEMS? They are mostly just thin pieces of
plastic and a little metal. The technolgy is not complicated compared
to the true innards of the polaris. but the configuration would have
to match. Any comments? am I nuts?

While the membranes aren't necessary if MIDI control can be utilized, I
have a situation where most MIDI messages are not recognized by my
Polaris, other than note on/off.

I commonly see the panels for the Moog Source for sale on eBay, but
never for the Polaris.

Given the number of units actually sold (or rather, the relative
obscurity of this particular synth as opposed to anything that
brandishes the Moog logo), let alone those experiencing the membrane
death problem, it would probably be more along the lines of a labor of
love for some very dedicated hobbyist, rather than a lucrative
enterprise for a small company.

Please allow for the possibility that I am, as usual, just talking out
my ass :P

--- In chromapolaris@yahoogroups.com, "spistrich" <wasteking@...> wrote:
>
> Would there be enough demand for an electronics manufacturer to make
a
> run of replacement switch panels for the polaris? Membrane switches
> are basically cheap, thats probably why they were used rather than
> better components. These could be sold with a set of replacement
> ribbon cables, would this be lucrative for some small elec
> manufacturer to invest in? How many bad polarises are there, and do
> they ALL HAVE THE SAME PROBLEMS? They are mostly just thin pieces of
> plastic and a little metal. The technolgy is not complicated compared
> to the true innards of the polaris. but the configuration would have
> to match. Any comments? am I nuts?
>

I think this falls in my area of expertise as I'm been doing prototype
HW design and research for the last 10 years for several fortune 50
companies...

The problem is that the layout of the polaris would require lots of
membrane area. Costs go up with area, so in the end the switch panel
replacement would probably cost close to $500 for qty <400.

There are 2 alternatives:
1) Non-form factor switch box (like a roland PG-xxx) which would be as
small a possible to save on costs, but would compromise the user
interface of the instrument (which is part of its character).

2) Which I have done successfullyand posted about on this list is to
drill out the panel and replace w/mechanical switches. This requires
removal of a few IC sockets for clearance on the rigid boards under the
panel. I'm getting pretty good at it, and using a thermal tweezer wire
stripper, its possible to avoid cutting and stripping 150+ wires to
make all the connections.

#2 sounds bad-- but nothing compared to what is done on some hammond
restorations.

I'm not looking to start a business, so please don't be offended by the
commercial nature of the following, but I would be willing to drill and
replace membrane panels for $300 (or more for higher quality switches--
prices range from $.30-$5.00 each!) and I have a spare so it could be
done as an exchange to minimize down time.

-Ben

--- In chromapolaris@yahoogroups.com, "spistrich" <wasteking@...> wrote:
>
> Would there be enough demand for an electronics manufacturer to make
a
> run of replacement switch panels for the polaris? Membrane switches
> are basically cheap, thats probably why they were used rather than
> better components. These could be sold with a set of replacement
> ribbon cables, would this be lucrative for some small elec
> manufacturer to invest in? How many bad polarises are there, and do
> they ALL HAVE THE SAME PROBLEMS? They are mostly just thin pieces of
> plastic and a little metal. The technolgy is not complicated compared
> to the true innards of the polaris. but the configuration would have
> to match. Any comments? am I nuts?
>

That sounds like a setup/utility option-- do you have a manual
handy? You want to look up the MIDI section and enable control
changes.

-Ben

--- In chromapolaris@yahoogroups.com, teknowh0re_1999 <no_reply@...>
wrote:

>
> While the membranes aren't necessary if MIDI control can be

utilized, I

> have a situation where most MIDI messages are not recognized by my
> Polaris, other than note on/off.
>
> I commonly see the panels for the Moog Source for sale on eBay, but
> never for the Polaris.
>
> Given the number of units actually sold (or rather, the relative
> obscurity of this particular synth as opposed to anything that
> brandishes the Moog logo), let alone those experiencing the

membrane

> death problem, it would probably be more along the lines of a labor

of

> love for some very dedicated hobbyist, rather than a lucrative
> enterprise for a small company.
>
> Please allow for the possibility that I am, as usual, just talking

out

> my ass :P
>
> --- In chromapolaris@yahoogroups.com, "spistrich" <wasteking@>

wrote:

> >
> > Would there be enough demand for an electronics manufacturer to

make

> a
> > run of replacement switch panels for the polaris? Membrane

switches

> > are basically cheap, thats probably why they were used rather

than

> > better components. These could be sold with a set of replacement
> > ribbon cables, would this be lucrative for some small elec
> > manufacturer to invest in? How many bad polarises are there, and

do

> > they ALL HAVE THE SAME PROBLEMS? They are mostly just thin pieces

of

> > plastic and a little metal. The technolgy is not complicated

compared

> > to the true innards of the polaris. but the configuration would

have

> > to match. Any comments? am I nuts?
> >
>

I purchased a Polaris off the analog list less than a year ago. The thing
is in almost perfect shape except that it appears two of the oscillators
won't come in tune. The auto-tune says they are, but they aren't. You can
tell when you play a scale, the 5th and 6th notes will just be off by a
couple of tones.

The guy who had it before said he just shut off those oscillators when he
used it, but that tends to take a way a bit of the polyphony.

Now, some people have told me the problem is the row of caps. I pulled it
apart, saw then, priced them etc. But I don't want to resolder a bunch of
these things (I think there were twelve) and then find out it didn't make a
difference.

Also, the machine seems to have "forgotten" everything. There are no
presets, or patches, or anything. I assume those can be reloaded?

I can do basic repairs myself (i.e. replace caps), on the other hand, I'm
not adverse to sending it to someone if they actually know what they're
doing.

Any advice?

--Tom

> ... I commonly see the panels for the Moog Source for
> sale on eBay, but never for the Polaris...

The same fella/company (chipforbrains/technologytransplant) also has panels
for the Sequential
Prophet-600, and I'd have to guestimate that the number of Polarii around
would be on-par with something like that. (I've ever really seen a shortage
of the Polaris keyboards - the don't match the quantities of something like
the Yamaha DX-7, but you always seem to be able to find one, if needed).

I'm a little surprised that with the huge number of companies that will make
custom membrane switch panels that no one has decided to try to make one for
the Polaris (if even only for their own personal use) (sure, some of these
can do fancy things - like have built-in LEDs which will be very expensive
or be waterproof to 10 atmospheres - but others do what are essentially
plain-jane panels).

> From: Tom Krotchko
>
> I purchased a Polaris off the analog list less than a year ago.
> The thing
> is in almost perfect shape except that it appears two of the oscillators
> won't come in tune. The auto-tune says they are, but they
> aren't. You can
> tell when you play a scale, the 5th and 6th notes will just be off by a
> couple of tones.
>
> Now, some people have told me the problem is the row of caps. I
> pulled it
> apart, saw then, priced them etc. But I don't want to resolder a
> bunch of
> these things (I think there were twelve) and then find out it
> didn't make a
> difference.

Do you have access to a scope? You can tell if the problems are in that area
by looking at the outputs of the sample-and-hold buffers (Zx03 and Zx04). If
they have a sawtooth-like modulation on them of more than a few millivolts,
then the voltages on the caps are drooping. This usually means the caps are
leaky, but could also be the 4051 switches, or even the buffers themselves.

--

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

> From: David Clarke
>
> I'm a little surprised that with the huge number of companies
> that will make
> custom membrane switch panels that no one has decided to try to
> make one for
> the Polaris (if even only for their own personal use) (sure, some
> of these
> can do fancy things - like have built-in LEDs which will be very
> expensive
> or be waterproof to 10 atmospheres - but others do what are essentially
> plain-jane panels).

Has anyone ever figured out where the problem actually is? I would suspect
cracks in the silver ink where the tails flex. This could be repairable by
painting on some more silver ink with a fine brush. If the problem is that
the switches themselves have collapsed, and are permanently shorted, then
they're probably unfixable.

--

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

Unfortunately, I don't have access to a scope which makes it difficult to
diagnose <G>.

--Tom

----Original Message Follows----
From: "Paul D. DeRocco" <pderocco@...>
Reply-To: chromapolaris@yahoogroups.com
To: <chromapolaris@yahoogroups.com>
Subject: RE: [chromapolaris] Another topic... 2 oscillators out of tune.
Date: Fri, 4 Aug 2006 14:48:19 -0700

> From: Tom Krotchko
>
> I purchased a Polaris off the analog list less than a year ago.
> The thing
> is in almost perfect shape except that it appears two of the oscillators
> won't come in tune. The auto-tune says they are, but they
> aren't. You can
> tell when you play a scale, the 5th and 6th notes will just be off by a
> couple of tones.
>
> Now, some people have told me the problem is the row of caps. I
> pulled it
> apart, saw then, priced them etc. But I don't want to resolder a
> bunch of
> these things (I think there were twelve) and then find out it
> didn't make a
> difference.

Do you have access to a scope? You can tell if the problems are in that area
by looking at the outputs of the sample-and-hold buffers (Zx03 and Zx04). If
they have a sawtooth-like modulation on them of more than a few millivolts,
then the voltages on the caps are drooping. This usually means the caps are
leaky, but could also be the 4051 switches, or even the buffers themselves.

--

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

> Has anyone ever figured out where the problem actually is? I would suspect
> cracks in the silver ink where the tails flex. This could be repairable by
> painting on some more silver ink with a fine brush. ...

The silver ink ideawill work for some of the boards, but the main
(catastrophic) problem is that the flex becomes so brittle that it will
actually break/crack all the way through. If the cracks are very close to
the end, then those can just be trimmed off - but if they're farther back,
then the repair is much tougher.

In a nutshell, the membranes themselves generally hold out - but the flex
from them fails (there are off course exceptions to that rule...)

I have 2 CPs where the switches themselves have worn out.

-Ben

> Has anyone ever figured out where the problem actually is? I would

suspect

> cracks in the silver ink where the tails flex. This could be

repairable by

> painting on some more silver ink with a fine brush. If the problem is

that

> the switches themselves have collapsed, and are permanently shorted,

then

> they're probably unfixable.
>
> --
>
> Ciao, Paul D. DeRocco
> Paul mailto:pderocco@...
>

> From: bkuris
>
> I have 2 CPs where the switches themselves have worn out.

How did you diagnose that? Are there only one or two bad switches? A break
in a line on the tail can take out either five or eight switches on the
right side of the panel (ENVELOPE through PROGRAM SELECT), or can take out
from three to eight switches on the left side of the panel (SEQUENCER
through FILTER).

--

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