Synth-DIY Yahoo! Groups Archives

New Member Hopefully New Owner

2015-05-30 by paul.krull@...

Hi All:

I just joined the list as I'm finally about to buy a Polaris after admiring them for 30 years or so. I'm a long time Chroma owner and Quadra/Odyssey/ 2600/Solus/ Etc. owner and I'm sort of aware of what I'm getting myself into by purchasing a Polaris with left hand panel issues but otherwise very clean and mint looking.

I haven't actually played a Polaris for many years and have played several, some with panel issues and some fully functional but it looks like there are some new developments what with new panels being made and discussion groups that include much informed input so I'm hopeful that there are fixes for a sickly Polaris these days.

Thanks,

Paul T

RE: [chromapolaris] New Member Hopefully New Owner

2015-05-31 by Paul D. DeRocco

> From: Paul T
>
> I haven't actually played a Polaris for many years and have
> played several, some with panel issues and some fully
> functional but it looks like there are some new developments
> what with new panels being made and discussion groups that
> include much informed input so I'm hopeful that there are
> fixes for a sickly Polaris these days.

I have replacement panels. You can see the installation process here:

http://www.rhodeschroma.com/?id=polarismembranepanelreplacement

Contact me off-list to purchase.

--

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

RE: [chromapolaris] New Member Hopefully New Owner

2015-06-03 by steve.welk@...

I can attest to the wonderfulness of Paul's panels, and also for his generosity in sharing his expertise. Thanks to his willingness to keep this cool instrument alive, my Polaris has been brought back from the dead. It sat for many years (5-10, who knows) in my basement pretty much out of commission due to the broken flex problem. I wasn't really sure what to do with it. Then I found a book ("Synth Gods") in a 1/2 price bookstore, and it reactivated my interest in old analog synths. It prompted me to research information on my old Polaris and i ran into Paul's replacement instructions.

Long story short, I bought a set of the panels. He helped me debug a couple other problems, convinced me to try fixing a couple bad sliders and gave other good info (e.g. part number/where to find the ribbon connectors). I now have a perfectly functioning (I think) Polaris again thanks to Paul. I was even motivated to replace a couple chipped keys, found on ebay so now it looks pretty excellent too.

Amazingly enough, my D cells still registered 4 LED's of goodness after sitting idle all that time. All presets were still there.

Anyway, only one question. When pushing my master volume up past ~ 1/3 full scale, it gets pretty noisy. I gather this is "normal". Was there ever a fix for this? Do dedicated analog voltages/ground from the power supply board help?

Again, kudos to Paul!

Steve

RE: [chromapolaris] New Member Hopefully New Owner

2015-06-03 by Bkuris@...

I also endorse the replacement panel.

I have 2 working, 1 problem child / donor unit-- I found that upgrading the opamp on the output board really improved the sound of these units after doing the well documented grounding change (which I can't remember but involved cutting a wire I believe).

I can run them at full volume without worrying about hiss, bass sounds clearer and more like you would want from a synth... I can't remember the exact parts that I ordered but they were in the $3-$15 range, likely something from burr-brown (maybe a newer TI excaliber TL207x) that was well regrading in the DIY audio community. The change wasn't subtle. Next time I have a unit open I'll take a closer look. It isn't a difficult mod -- remove old chip, add socket, add new chip. I'm sure someone industrious could do a drop-in board instead...

-Ben

Re: [chromapolaris] New Member Hopefully New Owner

2015-06-03 by Paul Krull

I have longingly studied the installation instructions for the replacement panels and they do seem pretty detailed and comprehensive. How many owners and with what kind of skill set have replaced their own panels? I worked in a music store that sold used synths many years ago and a couple Polarii came through with troubled membranes and I did do some investigating and poking around but it seemed like a losing battle with the brittle and deteriorating state of the ribbon. I hope I didn't leave the instruments in worse shape than I found them.

PT

On Tuesday, June 2, 2015 6:11 PM, "steve.welk@... [chromapolaris]" <chromapolaris@yahoogroups.com> wrote:

I can attest to the wonderfulness of Paul's panels, and also for his generosity in sharing his expertise. Thanks to his willingness to keep this cool instrument alive, my Polaris has been brought back from the dead. It sat for many years (5-10, who knows) in my basement pretty much out of commission due to the broken flex problem. I wasn't really sure what to do with it. Then I found a book ("Synth Gods") in a 1/2 price bookstore, and it reactivated my interest in old analog synths. It prompted me to research information on my old Polaris and i ran into Paul's replacement instructions.

Long story short, I bought a set of the panels. He helped me debug a couple other problems, convinced me to try fixing a couple bad sliders and gave other good info (e.g. part number/where to find the ribbon connectors). I now have a perfectly functioning (I think) Polaris again thanks to Paul. I was even motivated to replace a couple chipped keys, found on ebay so now it looks pretty excellent too.

Amazingly enough, my D cells still registered 4 LED's of goodness after sitting idle all that time. All presets were still there.

Anyway, only one question. When pushing my master volume up past ~ 1/3 full scale, it gets pretty noisy. I gather this is "normal". Was there ever a fix for this? Do dedicated analog voltages/ground from the power supply board help?

Again, kudos to Paul!

Steve

RE: [chromapolaris] New Member Hopefully New Owner

2015-06-03 by Paul D. DeRocco

> From: PT
>
> I have longingly studied the installation instructions for
> the replacement panels and they do seem pretty detailed and
> comprehensive. How many owners and with what kind of skill
> set have replaced their own panels? I worked in a music store
> that sold used synths many years ago and a couple Polarii
> came through with troubled membranes and I did do some
> investigating and poking around but it seemed like a losing
> battle with the brittle and deteriorating state of the
> ribbon. I hope I didn't leave the instruments in worse shape
> than I found them.

I've sold a lot of sets. Only a few people have had any difficulties, and
all of those problems were dealt with successfully.

--

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

Re: [chromapolaris] New Member Hopefully New Owner

2015-06-03 by Paolo albanese

Confirmed. I bought and installed Paul panels. Very good quality and easy installation. Then, all depends if someone before tried to repair the failed contact strips/panel and made a mess shorting or cutting it such as happened to my Polaris but I succedeed indeed. Paul Panels are awesome.

Inviato da iPhone

Il giorno 03/giu/2015, alle ore 19:39, 'Paul D. DeRocco' pderocco@... [chromapolaris] <chromapolaris@yahoogroups.com> ha scritto:

> From: PT
>
> I have longingly studied the installation instructions for
> the replacement panels and they do seem pretty detailed and
> comprehensive. How many owners and with what kind of skill
> set have replaced their own panels? I worked in a music store
> that sold used synths many years ago and a couple Polarii
> came through with troubled membranes and I did do some
> investigating and poking around but it seemed like a losing
> battle with the brittle and deteriorating state of the
> ribbon. I hope I didn't leave the instruments in worse shape
> than I found them.

I've sold a lot of sets. Only a few people have had any difficulties, and
all of those problems were dealt with successfully.

--

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

Re: [chromapolaris] New Member Hopefully New Owner

2015-06-03 by Bob Grieb

I replaced the panel on mine, and also helped a friend do his.

It's not that hard if you watch Paul's video and make sure

you follow each step.

Bob

From: "Paul Krull paul.krull@... [chromapolaris]" <chromapolaris@yahoogroups.com>
To: "chromapolaris@yahoogroups.com" <chromapolaris@yahoogroups.com>
Sent: Wednesday, June 3, 2015 12:41 PM
Subject: Re: [chromapolaris] New Member Hopefully New Owner

I have longingly studied the installation instructions for the replacement panels and they do seem pretty detailed and comprehensive. How many owners and with what kind of skill set have replaced their own panels? I worked in a music store that sold used synths many years ago and a couple Polarii came through with troubled membranes and I did do some investigating and poking around but it seemed like a losing battle with the brittle and deteriorating state of the ribbon. I hope I didn't leave the instruments in worse shape than I found them.

PT

On Tuesday, June 2, 2015 6:11 PM, "steve.welk@... [chromapolaris]" <chromapolaris@yahoogroups.com> wrote:

I can attest to the wonderfulness of Paul's panels, and also for his generosity in sharing his expertise. Thanks to his willingness to keep this cool instrument alive, my Polaris has been brought back from the dead. It sat for many years (5-10, who knows) in my basement pretty much out of commission due to the broken flex problem. I wasn't really sure what to do with it. Then I found a book ("Synth Gods") in a 1/2 price bookstore, and it reactivated my interest in old analog synths. It prompted me to research information on my old Polaris and i ran into Paul's replacement instructions.

Long story short, I bought a set of the panels. He helped me debug a couple other problems, convinced me to try fixing a couple bad sliders and gave other good info (e.g. part number/where to find the ribbon connectors). I now have a perfectly functioning (I think) Polaris again thanks to Paul. I was even motivated to replace a couple chipped keys, found on ebay so now it looks pretty excellent too.

Amazingly enough, my D cells still registered 4 LED's of goodness after sitting idle all that time. All presets were still there.

Anyway, only one question. When pushing my master volume up past ~ 1/3 full scale, it gets pretty noisy. I gather this is "normal". Was there ever a fix for this? Do dedicated analog voltages/ground from the power supply board help?

Again, kudos to Paul!

Steve

Re: [chromapolaris] New Member Hopefully New Owner

2015-06-13 by Paul

Yesterday I brought home Polaris #300740 according to the unopened warranty card. It is in immaculate condition: not a mark on it anywhere and the sliders all feel great plus the keys all work and seem to send the full range of velocity. The right side membrane is fully functional and the left side is completely dead. It still has all patches in it and sounds pretty good except the tuning is a little too spread out and I suspect I'll need the use of the left panel to tune it. I've got the manual and some aftermarket patches around here somewhere for some reason.

I'm not real eager to do anything to mess up the pristine condition of the case and the thought of skinning the bad membrane off with putty knives etc. is daunting.

Mr DeRocco: how much to ship a set of new panels to Seattle WA?

Sent from my iKaypro

On May 31, 2015, at 10:20 AM, "'Paul D. DeRocco' pderocco@... [chromapolaris]" <chromapolaris@yahoogroups.com> wrote:

> From: Paul T
>
> I haven't actually played a Polaris for many years and have
> played several, some with panel issues and some fully
> functional but it looks like there are some new developments
> what with new panels being made and discussion groups that
> include much informed input so I'm hopeful that there are
> fixes for a sickly Polaris these days.

I have replacement panels. You can see the installation process here:

http://www.rhodeschroma.com/?id=polarismembranepanelreplacement

Contact me off-list to purchase.

--

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

Polaris stubborn tuning problems

2015-07-09 by klosmon

Currently working on a Polaris that was severely mistreated.
Replaced the membrane panels, several pots; upgraded the ROMs; tuned &
scaled the power supply, DAC, CPU and voice board per the service manual.

Two voices (3 and 5) will not pass tune. Re-enabling them shows that
Oscillator B on both voices scales sharp towards the upper part of the
keyboard; also, when playing the filter resonance from the keyboard,
those two voices are out of tune with the rest.

What I've done so far: swapped out ALL ICs on the two offending voices
-- no change.
Swapped out all the sample/hold caps and oscillator timing caps on the
two offending voices -- no change.
Replaced the four ICs (Z60 - 63) in the sample/hold control circuit --
no change.

At this point, I'm out of ideas as to why these two voices are behaving
this way.
All memory functions, internal and external controls, and other synth
features are working correctly on all voices.

Any suggestions?
Thanks.
~GMM

Re: [chromapolaris] Polaris stubborn tuning problems

2015-07-09 by Bob Grieb

Until Paul jumps in, I guess anyone can throw out ideas,

so I will...

The output of each synth channel goes through a 4053 MUX to create

main out and alt out. Did you replace those on the two offending

voices? Also, did you scope the signal coming out of the

"tune buffer" and also the signal at the output of the 1489 Z46?
I know that those are not specific to particular voices, but maybe if

they are bad, some voices could be more affected than others?

Bob

From: "klosmon klosmon@... [chromapolaris]" <chromapolaris@yahoogroups.com>
To: chromapolaris@yahoogroups.com
Sent: Thursday, July 9, 2015 5:04 PM
Subject: [chromapolaris] Polaris stubborn tuning problems

Currently working on a Polaris that was severely mistreated.
Replaced the membrane panels, several pots; upgraded the ROMs; tuned &
scaled the power supply, DAC, CPU and voice board per the service manual.

Two voices (3 and 5) will not pass tune. Re-enabling them shows that
Oscillator B on both voices scales sharp towards the upper part of the
keyboard; also, when playing the filter resonance from the keyboard,
those two voices are out of tune with the rest.

What I've done so far: swapped out ALL ICs on the two offending voices
-- no change.
Swapped out all the sample/hold caps and oscillator timing caps on the
two offending voices -- no change.
Replaced the four ICs (Z60 - 63) in the sample/hold control circuit --
no change.

At this point, I'm out of ideas as to why these two voices are behaving
this way.
All memory functions, internal and external controls, and other synth
features are working correctly on all voices.

Any suggestions?
Thanks.
~GMM

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Re: [chromapolaris] Polaris stubborn tuning problems

2015-07-10 by klosmon

On 7/9/2015 4:51 PM, Bob Grieb bobgrieb@... [chromapolaris] wrote:

> Until Paul jumps in, I guess anyone can throw out ideas,
> so I will...
>
> The output of each synth channel goes through a 4053 MUX to create
> main out and alt out. Did you replace those on the two offending
> voices?

Yes, that was part of the "all ICs" on the offending voices.

> Also, did you scope the signal coming out of the
> "tune buffer" and also the signal at the output of the 1489 Z46?
> I know that those are not specific to particular voices, but maybe if
> they are bad, some voices could be more affected than others?

Yah, the ZCD signal looks the same for all oscillators.

Tomorrow I start measuring resistors & checking traces.
Will also look further back in the data lines to see if any disturbances
there might be causing some trouble.
~G

>
> Bob
>
> ------------------------------------------------------------------------
> *From:* "klosmon klosmon@... [chromapolaris]"
> <chromapolaris@yahoogroups.com>
> *To:* chromapolaris@yahoogroups.com
> *Sent:* Thursday, July 9, 2015 5:04 PM
> *Subject:* [chromapolaris] Polaris stubborn! tuning problems
>
> Currently working on a Polaris that was severely mistreated.
> Replaced the membrane panels, several pots; upgraded the ROMs; tuned &
> scaled the power supply, DAC, CPU and voice board per the service manual.
>
> Two voices (3 and 5) will not pass tune. Re-enabling them shows that
> Oscillator B on both voices scales sharp towards the upper part of the
> keyboard; also, when playing the filter resonance from the keyboard,
> those two voices are out of tune with the rest.
>
> What I've done so far: swapped out ALL ICs on the two offending voices
> -- no change.
> Swapped out all the sample/hold caps and oscillator timing caps on the
> two offending voices -- no change.
> Replaced the four ICs (Z60 - 63) in the sample/hold control circuit --
> no change.
>
> At this point, I'm out of ideas as to why these two voices are behaving
> this way.
> All memory functions, internal and external controls, and other synth
> features are working correctly on all voices.
>
> Any suggestions?
> Thanks.
> ~GMM
>
>
> ------------------------------------
>
> ------------------------------------
>
>
> ------------------------------------
>
> Yahoo Groups Links
>
>
> (Yahoo! ID required)
>
> chromapolaris-fullfeatured@yahoogroups.com
> <mailto:chromapolaris-fullfeatured@yahoogroups.com>
>
>
>
>
>
>

RE: [chromapolaris] Polaris stubborn tuning problems

2015-07-10 by Paul D. DeRocco

If you have, or can borrow, a scope, it might be useful to watch the
various S&H voltages during the auto-tune process, to find out at what
point the autotune fails. The order of operations is:

pitch 1 (5 different control voltages, width = mid, cutoff = max)
pitch 2 (5 different control voltages, width = mid, cutoff = max)
width 1 (2 different control voltages, pitch = 35Hz, cutoff = max)
width 2 (2 different control voltages, pitch = 35Hz, cutoff = max)
cutoff (2 different control voltages, pitch = 0, width = 0)

If you don't see the cutoff doing anything (other than momentarily going
to max), then it's never getting as far as tuning the filter. If you never
see the width doing anything (other than momentarily going to mid), then
it's never getting as far as measuring the pulse width. Etc.

--

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

Re: Polaris stubborn tuning problems

2015-07-10 by John Leimseider

It may sound dumb, but I would swap the DAC... If a particular oscillator just needs one bit that isn't needed by any of the other oscillators and it's bad, by coincidence, you can have them fail. It wouldn't show up on the others, because it isn't needed. I saw this on a Polaris, and it took way too much time to find it. Can't hurt to try it. Same DAC as an OB8...

Sent from my iPad

Re: [chromapolaris] Re: Polaris stubborn tuning problems

2015-07-10 by klosmon

Not dumb, but as I have several spare DAC chips, I tried that already.

Next plan is to dig into the service manual description of the Timer
Interface Serial I/O section, particularly as it relates to the tuning
process.
I'm starting to think that the voices are working correctly, but some
are receiving bad information. We'll see.

Thanks.
~GMM

On 7/10/2015 10:54 AM, John Leimseider john.leimseider@...
[chromapolaris] wrote:

>
> It may sound dumb, but I would swap the DAC... If a particular
> oscillator just needs one bit that isn't needed by any of the other
> oscillators and it's bad, by coincidence, you can have them fail. It
> wouldn't show up on the others, because it isn't needed. I saw this on
> a Polaris, and it took way too much time to find it. Can't hurt to try
> it. Same DAC as an OB8...
>
> Sent from my iPad
>
>

RE: [chromapolaris] Re: Polaris stubborn tuning problems

2015-07-10 by Paul D. DeRocco

> From: GMM
>
> Next plan is to dig into the service manual description of the Timer
> Interface Serial I/O section, particularly as it relates to
> the tuning process.

If the working channels end up in tune, then the timer circuitry is
probably fine.

> I'm starting to think that the voices are working correctly, but some
> are receiving bad information. We'll see.

The only thing outside the channels that isn't common to the channels are
the various decoded lines that enable the S&H switches and that clock the
data latches. Have you tried replacing the chips that generate those lines
(Z31, Z32, Z60, Z61, Z62)?

--

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

Re: [chromapolaris] Re: Polaris stubborn tuning problems

2015-07-10 by klosmon

On 7/10/2015 3:45 PM, 'Paul D. DeRocco' pderocco@...
[chromapolaris] wrote:

>
> > From: GMM
> >
> > Next plan is to dig into the service manual description of the Timer
> > Interface Serial I/O section, particularly as it relates to
> > the tuning process.
>
> If the working channels end up in tune, then the timer circuitry is
> probably fine.
>
> > I'm starting to think that the voices are working correctly, but some
> > are receiving bad information. We'll see.
>
> The only thing outside the channels that isn't common to the channels are
> the various decoded lines that enable the S&H switches and that clock the
> data latches. Have you tried replacing the chips that generate those lines
> (Z31, Z32, Z60, Z61, Z62)?
>

The S/H control parts (60, 61, 62) have already been changed, with no
effect.
I have 31 & 32 on order (along with a few other things) -- will see what
happens when they arrive,
Thanks.

Now, back to work on the distressed Rhodes Chroma (left exposed to sea
air for about ten years -- didn't think such corrosion was possible).
~GMM

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

Re: [chromapolaris] New Member Hopefully New Owner

2015-09-18 by masonhu@aol.com

Do panels/membranes deteriorate over time even if the unit is not being used?
(or is it mainly heavy use that causes them to break down?_

i.e. If someone's selling a pristine synth is there still a pretty good chance the original panels underneath might be shot?

On 6/3/2015 2:21 PM, Bob Grieb bobgrieb@... [chromapolaris] wrote:

I replaced the panel on mine, and also helped a friend do his.

It's not that hard if you watch Paul's video and make sure

you follow each step.

    Bob



From: "Paul Krull paul.krull@... [chromapolaris]" <chromapolaris@yahoogroups.com>
To: "chromapolaris@yahoogroups.com" <chromapolaris@yahoogroups.com>
Sent: Wednesday, June 3, 2015 12:41 PM
Subject: Re: [chromapolaris] New Member Hopefully New Owner

I have longingly studied the installation instructions for the replacement panels and they do seem pretty detailed and comprehensive. How many owners and with what kind of skill set have replaced their own panels? I worked in a music store that sold used synths many years ago and a couple Polarii came through with troubled membranes and I did do some investigating and poking around but it seemed like a losing battle with the brittle and deteriorating state of the ribbon. I hope I didn't leave the instruments in worse shape than I found them.

PT



On Tuesday, June 2, 2015 6:11 PM, "steve.welk@... [chromapolaris]" <chromapolaris@yahoogroups.com> wrote:

I can attest to the wonderfulness of Paul's panels, and also for his generosity in sharing his expertise. Thanks to his willingness to keep this cool instrument alive, my Polaris has been brought back from the dead. It sat for many years (5-10, who knows) in my basement pretty much out of commission due to the broken flex problem. I wasn't really sure what to do with it. Then I found a book ("Synth Gods") in a 1/2 price bookstore, and it reactivated my interest in old analog synths. It prompted me to research information on my old Polaris and i ran into Paul's replacement instructions.

Long story short, I bought a set of the panels. He helped me debug a couple other problems, convinced me to try fixing a couple bad sliders and gave other good info (e.g. part number/where to find the ribbon connectors). I now have a perfectly functioning (I think) Polaris again thanks to Paul. I was even motivated to replace a couple chipped keys, found on ebay so now it looks pretty excellent too.

Amazingly enough, my D cells still registered 4 LED's of goodness after sitting idle all that time. All presets were still there.

Anyway, only one question. When pushing my master volume up past ~ 1/3 full scale, it gets pretty noisy. I gather this is "normal". Was there ever a fix for this? Do dedicated analog voltages/ground from the power supply board help?

Again, kudos to Paul!

Steve

Re: [chromapolaris] New Member Hopefully New Owner

2015-09-18 by Bob Grieb

Paul D is the expert on this, of course. It's the tails that are used to connect to the panels
that become brittle with age and crack, breaking the connections. I don't think these flex much
with use, so I would guess that it's just age-related and probably has little to do with use.

But maybe if the synth is in a moister environment the tails might not dry out as much?
Of course a moist environment can lead to lots of other issues...

Bob
--------------------------------------------

On Fri, 9/18/15, 'masonhu@...' Masonhu@... [chromapolaris] <chromapolaris@yahoogroups.com> wrote:

Subject: Re: [chromapolaris] New Member Hopefully New Owner
To: chromapolaris@yahoogroups.com
Date: Friday, September 18, 2015, 10:19 AM

Do panels/membranes deteriorate over time even if the
unit is not
being used?

(or is it mainly heavy use that causes them to break
down?_

i.e. If someone's selling a pristine synth is there
still a pretty
good chance the original panels underneath might be
shot?

On 6/3/2015 2:21 PM, Bob Grieb bobgrieb@...
[chromapolaris] wrote:

I replaced
the
panel on mine, and also helped a friend do
his.
It's
not that
hard if you watch Paul's video and make
sure
you follow
each
step.

    Bob



From:
"Paul Krull paul.krull@...
[chromapolaris]" <chromapolaris@yahoogroups.com>

To:
"chromapolaris@yahoogroups.com"
<chromapolaris@yahoogroups.com>

Sent:
Wednesday, June 3, 2015 12:41 PM

Subject:
Re: [chromapolaris] New Member
Hopefully New Owner

I

have longingly studied the
installation
instructions for the
replacement panels
and they do seem pretty
detailed and
comprehensive. How many owners
and with
what kind of skill set have
replaced their
own panels? I worked in a
music store that
sold used synths many years
ago and a
couple Polarii came through
with troubled
membranes and I did do some
investigating
and poking around but it
seemed like a
losing battle with the brittle
and
deteriorating state of the
ribbon. I hope
I didn't leave the
instruments in worse
shape than I found
them.
PT


On Tuesday, June 2,
2015 6:11 PM, "steve.welk@...

[chromapolaris]" <chromapolaris@yahoogroups.com>
wrote:

I
can attest to
the
wonderfulness
of Paul's
panels, and
also for his
generosity in
sharing his
expertise.
Thanks to his
willingness to
keep this
cool
instrument alive, my
Polaris has
been brought
back from the
dead. It
sat for many
years (5-10,
who knows) in
my basement
pretty much
out of
commission due
to the
broken flex
problem. I
wasn't
really sure what to
do with it.
Then I found
a book
("Synth Gods") in a
1/2 price
bookstore, and
it reactivated
my interest
in old analog
synths. It
prompted me to
research
information on
my old
Polaris and i
ran into
Paul's
replacement

instructions.

Long story
short, I bought
a set of the
panels. He
helped me
debug a couple
other
problems, convinced
me to try
fixing a couple
bad sliders
and gave other
good info
(e.g. part
number/where
to find the
ribbon
connectors). I now
have a
perfectly
functioning (I
think)
Polaris again
thanks to
Paul. I was
even
motivated to
replace a
couple chipped
keys, found
on ebay so now
it looks
pretty
excellent too.

Amazingly
enough, my D
cells still
registered 4
LED's of
goodness after
sitting idle
all that
time. All
presets were
still
there.

Anyway, only
one
question.
When pushing my
master volume
up past ~
1/3 full
scale, it gets
pretty noisy.
I gather
this is
"normal". Was
there ever a
fix for
this? Do
dedicated analog

voltages/ground from the
power supply
board help?

Again, kudos
to Paul!

Steve

RE: [chromapolaris] New Member Hopefully New Owner

2015-09-18 by Paul D. DeRocco

> From: Bob
>
> Paul D is the expert on this, of course. It's the tails
> that are used to connect to the panels
> that become brittle with age and crack, breaking the
> connections. I don't think these flex much
> with use, so I would guess that it's just age-related and
> probably has little to do with use.
>
> But maybe if the synth is in a moister environment the tails
> might not dry out as much?
> Of course a moist environment can lead to lots of other issues...

No one knows what actually causes the failures, but I don't think it's
lack of moisture. I think it's a chemical reaction between the Mylar (if
it really is Mylar) and either something in the silver ink or the green
"protective" backing. But whatever it is, it apparently has nothing to do
with heavy use.

--

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