Rhodes Chroma Polaris group photo

Yahoo Groups archive

Rhodes Chroma Polaris

Index last updated: 2026-04-28 23:17 UTC

Thread

Sample and hold capacitors

Sample and hold capacitors

2006-08-31 by spistrich

My polaris seems to have what has been described here as the "bad S+H 
capacitor permanently detuned  scale problem ".... this appeared when 
i got it back from a repair shop.  Could something that they did  
there 'blow' the caps?  such as soldering an additional battery to the 
main board to supposedly save the memory when it was taken out of the 
unit? would this have temporarily doubled the voltage in the system? 
The tech claims that the "program is corrupted"  referring to the 
programmed sounds,explaining why they sound out of tune .  but he cant 
apparently reload the sounds, the unit wont take the new  cassette 
feed data.  ( or else  it does but that is simply NOT the problem )   
he doesnt say muchabout  the capacitors.. but I dont think he knows 
for sure... Ive tried to tell him about the S+H caps, but its as if 
they dont want to listen to what other people say. But the unit played 
OK for tuning when i brought it in....  any ideas on what would cause 
the caps to fail if supposedly only a slider and LED  were replaced.? 
last i heard  they just want to give me my money back  along with a 
disfunctional unit (the place is a large 'factory authorized 'music 
equip.  outfit for a lot of southern New England.} I wonder what has 
happenned.

Re: [chromapolaris] Sample and hold capacitors

2006-09-01 by David Clarke

> ... The tech claims that the "program is corrupted"
> referring to the programmed sounds,explaining why
> they sound out of tune .  but he cant
> apparently reload the sounds, the unit wont take the new  cassette
> feed data.

To try to rule in/rule out if there could be something 'funny' with the 
program memory, perhaps the easiest thing to do (and this is something 
that the tech should be able to do) is to erase one of the patches. 
This should leave a 'scratch patch' present.  While not a really rich 
sound, this should provide a very basic patch.  If that has a similar 
tuning problem going up the keyboard, then it isn't the patch data.

Another item is - if the problem occurs at regular intervals (e.g., 
every 6th note, etc.), then it won't be the patch - as the same patch 
'data' is used for each key.

It is possible that some of the 'stored configuration data' on the 
keyboard may have been accentally corrupt (depending what the folks did 
in the shop).  If so, then some of the VCA settings or key sensitivity 
data may be bad/off.  Since velocity can be routed to different 
functions on the Polaris, if the velocity data is 'off' it can make 
certain patches sound 'funny' on certain keys.

Velocity settings are on a key-by-key basis - so if the problems follow 
certain keys, then this sounds reasonable.  If the problem is periodic 
(e.g., follows a 'voice'), then it is more likely voice specific.

In terms of the VCA and velocity data, those settings can be readjusted 
by following the steps in the "Adjustments and Checkout" sections 
(Section 6) of the Service Manual 
(http://www.rhodeschroma.com/content/polaris/servicemanual.pdf)

David

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.