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Subject: Re: [chromapolaris] Sample and hold capacitors

From: David Clarke <ac151@...>
Date: 2006-09-01

> ... 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