Yamaha CS80

rj krohn wrote:

Thanks Tom - good timing on this.  I just had a CS80 dropped off
yesterday for a tuning.  Most of it went quickly, but a couple of the
tuning trim pots appear to have corroded and don't work.  I need to pick
up some replacements.
> 1-biggest thing for me-do NOT move on to octaves 4,8,16 until you are ABSOLUTELY sure that you got the SCALING right on octave 2. 
>   
Definitely agree on this!  One question about this (Crow? Kent?): the
tuning guide says to tune and scale using A4 (the highest A key) and A1
(the lowest).  However, in the service manual, around the M-card
schematics, it says to use the highest and lowest C.  I'd think this
would be better and I'm guessing they wrote A in the tuning guide since
it's a nicer frequency to spot on a counter. However, I think we're all
using strobe or chromatic tuners.
> 2- if you have a laptop, KATSURA makes a $15 strobe tuner plug-in. i used it, and its 100000000% better than the korg chromatic guitar tuners. completely worth it. do not use it as mic, use the line-in, preferably in ADDITION to listening.(dont think i could have done it without haviing BOTH).
>   
That sounds great.  Oops - Mac only :(
> 3-i did ALL the voices with a strobe tuner INDEPENDENTLY, not tuning voice 1 osc 1 to voice 1 osc 2, but by only listening to each osc at a time. follow service manual instructions for panel settings, worked good for me. of course, ring mod/sub osc off. THEN, i lowered the voice board, and closed the hood. i left the machine on for 1/2 hr, and then did step #4:
>
> 4-using a graph chart, as well as the strobe tuner, i went through each voice(now using both oscs) and listened for dissonance/beats.
Can't argue with success.  This would work much better with the gate
LEDs I added.  Otherwise, it's very hard to track which voice you're
playing. You have to keep turning it off and back on to reset to voice
one.  Instead, I put a heater in the room and crank it up for a while
until the air is pretty hot. Then, the difference with the unit opened
up shouldn't be too great. I guess it's worse for early units with the
old VCO chips.
>
> 5-a word on voice 8. i did not know this
>   
Pretty simple, once you know the trick
> 6-actually, having 2 twist ties in noose shape was hugely helpful, cause if i ever needed to keep 2 keys depressed, this did the trick.
>
> 7-dunno if others have this experience, but my voices were not in the seats that the manual said they would be. 
I don't pay attention to the slot numbers.  It's really easy to find the
cards. The first group of 8 are 1 through 8 (left to right) for channel
1.  The next group is channel 2.  Sometimes I take an indelible pen and
write the  board names on the metal frame they're screwed into.

Happy tuning!

 David