Yamaha CS80

> 	dzlvs8 <mailto:dzlvs8@...>
> March 13, 2011 10:31 AM
>
>
> Hi, I am new to this group and new to the CS synths. I have a CS-50 
> that is in dire need of calibration and maybe more. I was following 
> this procedure ( 
> http://personal.inet.fi/private/matador/cs-80_adjustment_procedure.html ) 
> to just try to do the tuning portion of it (steps 8-12) and then one 
> voice just kind of slowly started getting a lower and lower frequency 
> until it just went away. I turned the keyboard off and back on and the 
> voice would come back and fade away again.
>
> I dont know if this is a problem that someone knows exactly what it is 
> but I wasnt even tuning the voice card that got the problem. So, the 
> first thing I want to do is calibrate the entire device and then see 
> if there is a bad cap or something? maybe??? The note totally went 
> away for almost a day and then I wiggled some stuff and it came back 
> again and started doing the same frequency lowering thing.
>
> Anyway, in case this is just a calibration issue, I would like to 
> fully calibrate the CS-50 BUT THE CS80 CALIBRATION INSTRUCTIONS SEEMS 
> TO REFER TO BOARDS THAT I DONT HAVE. DOES ANYONE HAVE CS-50 SPECIFIC 
> CALIBRATION INSTRUCTIONS?????
>
>
> My other issue is that one of my other voice cards will not tune 
> correctly. The difference in the notes as you go to different octaves 
> changes at an incorrect scale as you switch down to lower keyboards 
> settings using the "one octave lower" and "two octave lower" tab. I 
> have done all that I can with the trimmer pots on step 8-12 to try to 
> fix this but the range of the trimmer pots dont go where I need them 
> to to fix the problem. The problem seems to probably be in the voltage 
> supplied to the board??? or the octave ladder network (but I only have 
> the problem with one voice). AND I cant find the KAS board that the 
> CS-80 calibration instruction refer to in a CS-50.
>
> Can anyone help me or point me in the right direction?
> ------------------------------------------------------------------------
>
> 	Quazimodo <mailto:noddyspuncture@...>
> March 13, 2011 1:08 PM
>
>
> Hi, the only difference in the voice cards between the CS-50, 60 and 
> 80 are a few resistors I belive. Calibration procedure is exactly the 
> same. The KAS board will more than likely be under the keyboard 
> assembly. I've never seen a CS50 so I am just assuming. Your 
> intermittent fault, losing the voice, could well be a broken 
> connection - either dry joint or a wire break. Try wiggling the looms 
> again. I have found broken wires that way in my CS80. Also, the scale 
> thing. Last time I tuned my CS80 I also had a scale problem and it was 
> mentioned here that the VCO chips can actually change over time and 
> become out of spec on different footages. The tuning procedure says 
> set the scale on the highest footage range. If this is your problem 
> you'd need to set it on the lower (8ft) range. Then it will be out 
> higher up, which is less noticable. Otherwise you'll need new VCO chip.
>

I have the CS50 service manual (along with all the others) at my 
website: www.therogoffs.com/cs80


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