Yamaha CS80

All,

In trying to calibrate the CS50 and I have a persistent 6.5V at the TU point on the KAS board. Neither the trim pot (VR11) on the SUB board nor the pitch control knobs have any effect on this voltage. The only possible culprit I can identify is the 4558D on the sub board. Is this correct, or are there other components I should look at? The YM26700 seems to be down stream and is dividing this 6.5 up as it should.

Lots to learn!

Matt in Oakland

Okay,

No -'hey I figured it out' here. I bought a SUB board from Doug (synthparts.com), moved the wires over and a few chips, and hey: was able to adjust to 4.000 volts at Tu on the KAS board, and the pitch control makes an audible difference.

The next calibration step is to get 125mV at pin 13 on the 26700 chip, but of course I have 250mV and adjusting VR1 on the KAS board does nothing. Sigh. What could go wrong here?

Thanks,
Matt in Oakland

--- In yamahacs80@yahoogroups.com, "velomatte" <velomatte@...> wrote:
>
> All,
>
> In trying to calibrate the CS50 and I have a persistent 6.5V at the TU point on the KAS board. Neither the trim pot (VR11) on the SUB board nor the pitch control knobs have any effect on this voltage. The only possible culprit I can identify is the 4558D on the sub board. Is this correct, or are there other components I should look at? The YM26700 seems to be down stream and is dividing this 6.5 up as it should.
>
> Lots to learn!
>
> Matt in Oakland
>