Archive of the former Yahoo!Groups mailing list: Rhodes Chroma Polaris

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Subject: Re: Slider problems

From: "bkuris" <benjamin.kuris@...>
Date: 2004-08-03

The part of the ribbon that breaks is on the bends. Actually I think
the sliders use the wire connectors not the flex, but I'll need to
double check.

I just bought a 2nd polaris last night and it is a bit sick so I'll
dig out my service manual w/calibration info in the next few days and
revisit the ADC circuitry. I can email a .pdf of the proceedure or
post to this file area if it is open.

One thing I highly recommend is lifting the ground from the headphone
jack and grounding it along w/the other jacks (orange wire on my
polaris, blue wire is disconnected). That removes digital hash noise
from the phones output.

While you are checking out the unit, listen for inconsistancies
between voices. For example, the polaris I'm debugging now has a
voice that is permanently detuned. I tracked it down to a bad op-amp
(TL084) last night and am waiting for a replacement part. If you
play a sequence of 6 notes, you can identify the bad voice and then
just hold the bad note. To narrow down which voice, I use a tweezer
destabilize the voice chip-- you can tap on pin 4 (maybe 5) of the
CEM3374 and hear a change in the voice if it is the chip that is
playing now. Be careful not to short anything!


--- In, Byron IV <earworm@g...> wrote:
> Thanks for the info Ben, I'm quite glad I didn't attempt to touch
> now (I have a tendency for fiddling when it comes to gear). from
> I could actually see of the ribbons, they didnt appear broken, but,
> didn't remove the panels, and could only see the bends of them
> basically. Let me know if you find the calibration procedures, If it
> keeps kicking after that, I won't feel the need to fix the ribbons
> until I'm forced to (which will most undoubtably be at the worst
> hehe)
> Thanks,
> Byron