Archive of the former Yahoo!Groups mailing list: Yamaha CS80

previous by date index next by date
previous in topic topic list next in topic

Subject: Re: [yamahacs80] Re: CS-50 Calibration

From: David Rogoff <david@...>
Date: 2011-03-13

> 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


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