Yamaha CS80

Ringmodulator
When I set the rm's modulation-slider at max, there's some small 
increase of noise (like white noise etc), the speed setting has no 
effect and can not be heard.

Sub osc:
when I select saw up, saw down, pulse or noise, I can hear the lfo 
when I set the speed and vcf-destionation-slider at max. Vca- and vco 
slider settings have no effect.
However, when trying this I noticed that the lfo-speed could be heard 
as triggers at my left output. This disappeared when I opened up the 
panel. My guess is that it was caused by the multicable that runs at 
the right side. During the past 30 years, it has bended the PRA-board 
a bit to the left. Either the cable caused some crosstalk itself with 
the PRA-board or it caused the PRA to crosstalk with it's neighbour, 
OE2. Everytime you close the panel, the cable will rest in a slightly 
different position. Still, the SUB-board it miles away from all this 
so I guess it must be the multicable. You never know with this 
synth...


--- In yamahacs80@yahoogroups.com, "Laurie Curry" <laurie@...> wrote:
>
> I believe I also hear some leakage from my RM circuit....
> -----Original message-----
> From: "Max Fazio" faxiomas@...
> Date: Mon, 09 Jun 2008 02:47:54 -0600
> To: yamahacs80@yahoogroups.com
> Subject: [yamahacs80] problem: audible modulations at no playing.
> 
> Hi, writing here for a friend's CS80.
> My friend found a strange problem: when he does set the ringmod's
> speed at full with modulation at full , the sound coming from the
> modulator is quite hearable : the fact is that this sound you can 
hear
> even without playing anything on the keyboard; same problem happens
> with the SubOScillator: when he sets the speed at full, the sound 
can
> be heard without any key pressed.
> I believe there must be something wrong with some preamps in OE1 
board
> or PRA's muting FETs, my idea is to look at R51/52 to see if is 
there
> any faulty resistor concerning the Suboscillator.
> 
> Anyway I'm looking for your savvy advices.
> Thx for anyreply.
> M 
> 
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