Yamaha CS80

--- In yamahacs80@yahoogroups.com, David Rogoff <david@...> wrote:
> Using a frequency counter to tune a musical instrument is almost 
always 
> a really bad idea. 

Well, it was quite helpful, last night.
Only in combination with the MAM tuner, and for the high end of the 
frequency range, though.

It's helpful that the required frequencies are printend in the Yamaha 
tuning instructions - I guess it'd be a nightmare to tune an 
instrument looking into a frequency table.

But here, it worked like a charm. In a range of several kHz, I could 
really fine tune to about 2Hz - that's the utmost of resolution I 
could get out of the multiturn trimpots. With the MAM tuner (*when* 
it catched the right note), it was more like 8Hz of resolution.

On the low end (adjusting the offset voltage), in the range of a few 
hundred Hz, the frequency counter was of no use, however. The 
displayed frequency was wandering too much. But here the MAM tuner 
was perfect: It's resolution better than the offset trimpot's (single 
turn!) resolution.

So, in one evening, I had my CS-80 tuned well enough for playing 
chords that don't sound harsh anymore.

But this is still with the *open* synth, cards in "up" position.
I did put a towel on top of the card cage (thanks again for the 
hint!); now I'm curious how well the tuning will hold when the synth 
is closed again.
(I noticed a drift of almost 10Hz at the highest C in 2', from 1 hour 
after turn-on to 1.5 hours after turn-on, with the open, towel-clad 
synth.)

From what I've experienced so far, the main limit for precise tuning 
(other than heat, of course), is the resolution of the trimpots. 
Especially considering the awkward position in which I have to adjust 
them. :)

JH.