Yamaha CS80

During the procedure of CS60 calibration,  I read at paragraph III "TOUCH RESPONSE CONTROL CIRCUIT", in the SUB board : "adjust VR4 so that  the center voltage of OO output terminal becomes 0.5 +- 0.1 V"
This is cryptical to a newbie like me… what should I do?


Thanks

F

You need an oscilloscope.  They want you to look at the waveform on the 
OO terminal and adjust it so the center voltage of the sine wave is 0.5 
volts.  Not sure why they want it offset and not centered around zero, 
but I don't have time to dig through the schematics at the moment.

  David

> papinje <mailto:fernandozarone@...>
> January 27, 2012 6:59 AM
> During the procedure of CS60 calibration, I read at paragraph III 
> "TOUCH RESPONSE CONTROL CIRCUIT", in the SUB board : "adjust VR4 so 
> that the center voltage of OO output terminal becomes 0.5 +- 0.1 V"
> This is cryptical to a newbie like me... what should I do?
>


[Non-text portions of this message have been removed]

Thank you David.
Yes, it's clear now, although not too evident why this has to be done, as you stated. 

BTW
as to the oscilloscope, in my "advanced" hobbyist experience, after fixing so many analogue machines, overhauling my CS-80 mammoth last year has been paramount for me, not only for the unique character of the machine, that I do belove, but also because for the first time I have used a scope (an old, used Tektronix 50 Mhz, perfect for my necessities and � vintage smelling  :-)
I was introduced to this intriguing instrument by the  friend of mine Mario Maggi, who spent hours over the phone teaching me its use. Now I understand that nothing can be done without it, but minor fixing, especially when we deal with calibration; moreover, it has an impressive didactic power for who really want to understand the basics of sound synthesis. And yes, I bought it used for a few hundred euros...   
Now the CS-80, after a complete recapping, replacement of faulty ICs and an accurate CALIBRATION, sounds much better, like a new machine!

Thanks to David and to the list friends, without your precious help the mission would have been quite� impossible!









Il giorno 27/gen/2012, alle ore 18:11, David Rogoff ha scritto:

> You need an oscilloscope. They want you to look at the waveform on the 
> OO terminal and adjust it so the center voltage of the sine wave is 0.5 
> volts. Not sure why they want it offset and not centered around zero, 
> but I don't have time to dig through the schematics at the moment.
> 
> David
> 
> > papinje <mailto:fernandozarone@...>
> > January 27, 2012 6:59 AM
> > During the procedure of CS60 calibration, I read at paragraph III 
> > "TOUCH RESPONSE CONTROL CIRCUIT", in the SUB board : "adjust VR4 so 
> > that the center voltage of OO output terminal becomes 0.5 +- 0.1 V"
> > This is cryptical to a newbie like me... what should I do?
> >
> 
> [Non-text portions of this message have been removed]
> 
> 



[Non-text portions of this message have been removed]