Rhodes Chroma Polaris

Hello all

the new panels are on and work great. fixed a single LED that wasn't working, loaded up a cassette of sounds from the "orphan synth" library for the polaris. looking and sounding very good.

I have one remaining issue. for some reason the chroma polaris doesn't seem to be responding to the volume slider. this is true in the master section and in the assignable controller section. in fact, while all led's work and all membrane switches work, those two sliders seem to not be registering. at least the synth is simply playing at full volume.

if I can get those working again I'll be 100% on this synth. at least I'm using it again now and I'm close to happy. Not sure if my issue now is hardware or software. I did also change the batteries in this while I was doing the other work, so the synth has been reset, rebatteried, gotten the new panels, new sounds, and is mostly working right. Just got to get those last two sliders working whether it's a hardware or software issue. any ideas most welcome. now I've gotten a taste for fixing these things myself.

cheers,

Paul Kavicky
Paper Street Audio Company
www.paperstreetaudio.com

> From: James
>
> You can desolder the sliders off the board and check them
> with a multimeter easy enough. Make sure all connections are tight.
>
> Honestly, I've seen this before where a few sliders were dead
> yet the connections and sliders tested good. My fix involved
> replacing the 4052 multiplexers (going from memory) impacting
> the non working sliders. I've seen 'channels' on these
> multiplexers go out leaving some sliders working and some
> not. The 4052's are CHEAP and are still made in qty.

You can actually check the sliders in place, because they have static 5V
across them. Just hook a meter between ground and the wiper, and see if the
voltage goes from 0 to 5V as you vary the pot. It's hard to identify a noisy
pot with a meter, but you can easily see if it's totally broken. If you get
0 to 5V, but no effect on the sound, then change the CMOS switch. (They're
4051, although a more modern 74HC4051 will work just as well.)

--

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

Hi John,

All of the slider pots in my Polaris are the white body kind: Since these are prone to failure as you say, I'd like to get a set of the stronger replacement pots as backup against future needs.

Is MusicTek still offering these replacement parts? If not, would you (or Paul, of course) have a replacement part number to suggest I look into?

Thanks,

Syntegrator

--- In chromapolaris@yahoogroups.com, "John Leimseider" <leimseiderj@...> wrote:
>
> The Polaris had two types of slide pots… The earlier ones were really fragile. They have the white bodies. They were replaced with much stronger ones, but there is a different footprint. All then later panel boards were drilled for both types. The earlier ones (at least most of them) have the holes for both, but don’t have the same mounting holes. When MusicTek bought the Chroma and Polaris stock from Fender, we got about 1700 of the new pots. To install them on the early boards, you had to cut some of the legs from each pot. These later ones are really solid. The early ones would get bad if they got pushed in from the top, or bumped from the side. I replaced LOTS of them.
>
> I’d be really suspicious of the pots, if they’re the early ones, before worrying about the MUX or other electronic stuff. Just see if the wiper voltage is correct on the bad ones.
>
> John Leimseider
>
> Electronics Technician/ Technicien des instruments électroniques
>

MusicTek is essentially closed now. I've been at Cantos Music foundation in Calgary for almost 10 years. I'll have to see of we have them here. I know MusicTek still has a box of 1000 in storage.

________________________________

From: chromapolaris@yahoogroups.com on behalf of syntegrator
Sent: Wed 3/28/2012 8:06 PM
To: chromapolaris@yahoogroups.com
Subject: [chromapolaris] Re: working better




Hi John,

All of the slider pots in my Polaris are the white body kind: Since these are prone to failure as you say, I'd like to get a set of the stronger replacement pots as backup against future needs.

Is MusicTek still offering these replacement parts? If not, would you (or Paul, of course) have a replacement part number to suggest I look into?

Thanks,

Syntegrator

--- In chromapolaris@yahoogroups.com <mailto:chromapolaris%40yahoogroups.com> , "John Leimseider" <leimseiderj@...> wrote:
>
> The Polaris had two types of slide potsâEUR¦ The earlier ones were really fragile. They have the white bodies. They were replaced with much stronger ones, but there is a different footprint. All then later panel boards were drilled for both types. The earlier ones (at least most of them) have the holes for both, but donâEUR(tm)t have the same mounting holes. When MusicTek bought the Chroma and Polaris stock from Fender, we got about 1700 of the new pots. To install them on the early boards, you had to cut some of the legs from each pot. These later ones are really solid. The early ones would get bad if they got pushed in from the top, or bumped from the side. I replaced LOTS of them.
>
> IâEUR(tm)d be really suspicious of the pots, if theyâEUR(tm)re the early ones, before worrying about the MUX or other electronic stuff. Just see if the wiper voltage is correct on the bad ones.
>
> John Leimseider
>
> Electronics Technician/ Technicien des instruments électroniques
>

Thanks for looking into this for us all. With Paul now providing replacement membrane panels, it's a good time for these sliders to hit the market, I think... ;-)

All the best,

Syntegrator

--- In chromapolaris@yahoogroups.com, "John Leimseider" <leimseiderj@...> wrote:
>
> MusicTek is essentially closed now. I've been at Cantos Music foundation in Calgary for almost 10 years. I'll have to see of we have them here. I know MusicTek still has a box of 1000 in storage.
>
> ________________________________
>
> From: chromapolaris@yahoogroups.com on behalf of syntegrator
> Sent: Wed 3/28/2012 8:06 PM
> To: chromapolaris@yahoogroups.com
> Subject: [chromapolaris] Re: working better
>
>
>
>
> Hi John,
>
> All of the slider pots in my Polaris are the white body kind: Since these are prone to failure as you say, I'd like to get a set of the stronger replacement pots as backup against future needs.
>
> Is MusicTek still offering these replacement parts? If not, would you (or Paul, of course) have a replacement part number to suggest I look into?
>
> Thanks,
>
> Syntegrator