Yamaha CS80

Dear CS-80 friends,

just want to report that my CS-80 no. 1271 has been successfully 
resurrected. I bought it 8 years ago from a guy in switzerland who had 
it sitting around probably more than 20 years without any service in 
his garage. Shame on me, I found no time earlier to take care of this 
baby, but now it plays like new again!

Needless to say, I am pretty impressed by the quality and depth of its 
sound when fully calibrated to factory specs.

Since this was my first CS80 to take care of, let me share my 
experiences when going through the complete tuning procedure:

1) Some Keys had no velocity: First I suspected some damaged 4000 chips 
and started swapping these on the TSB boards- until i noticed that the 
reason was actually some bend metal contacts on the Key sensors, grrr! 
Re-aligning the contacts helped immediately. 

2)Following the tuning procedure I stucked quite early because the 
voltages on the KAS board seemed way off what should be right and could 
not be adjusted with the VR trimmers to factory spec. It took me quite 
some time to realize that I was using the wrong ground for this 
measurement, I took electrical ground straight from the PSU- but when 
taking the ground directly from KAS board it read out the proper 
Voltages perfectly. So from then, I always pick up ground from the card 
I am working on, not the PSU ground.

3) Pitchbend did not work: Changed CA3140 on BA board

4) Reference tuning Voltage on KAS board dropped from 4 Volts to 0 
Volts suddenly: Broken TR29 on BA board.

5) Reference tuning voltage on KAS board suddenly went to 8 Volts: 
Broken 4069 clock

6) enevelopes sounds different for VCA and VCF on each Voice, and some 
Voices had no attack at all. First I suspected some broken ENV chip 
here. The complete alignement of the envelopes is a quite elaborate 
procedure. I had to buy a digital oscilloscope for it and go thru the 
procedure several times, but finally everything could be adjusted 
without the need of exchanging ENV chips.

7) Output level of Voice cards was different for each voice. Adjusting 
the levels to factory specs (VCA gain should be 80mV) resulted in a 
very low general output level, so I suspect this value is wrong. I just 
increased the level up to 200-300mV, just before it starts clipping the 
chorus and ensemble section. Now the output is much hotter and SN ratio 
of Effect section much better.

8) Effect section: The adjustment procedure for the chorus and ensemble 
section seemed not to work well on my particular unit, so I adjusted 
this by ear to a minimum of noise and a reasonable effect level, 
skipping the specified values here.

9) Tuning of Voice boards: Looking on my Voice boards I found no 
temperature compensation diode, it is printed on the board but not 
fitted. But tuning my unit was quite easy finally, after completing the 
tuning procedure it is in tune immediately when switched on and stays 
like this pretty well. It seems I have some magic VCOs...

Now the only issue left is to replace a bulb in on of the program 
buttons, but this should be not a big problem,

cheers, Gregor

Hi Will,

congratulations! I should adjust the Chorus/Tremolo section of mine, too. Any advice how to do it? Any caveats? I wouldn´t want to haul my CS around just for that minor bit of surgery...

Stephen

____________________________________________________________________

"Ambition makes you look pretty ugly, kicking squealing Gucci little piggy." (Thom Yorke/Radiohead -- "Paranoid Android") 

Stephen Parsick live in concert: Bochum Planetarium (Germany), 13th of December, 2008, 08:00 pm.

Finally available: Stephen Parsick -- Traces of the Past Redux, reissued with three previously unreleased bonus tracks. For more info please check www.parsick.com

For legal downloads please check:

http://www.musiczeit.com/directory.php?artist=296&title=Stephen+Parsick

  ----- Original Message ----- 
  From: willgregori 
  To: yamahacs80@yahoogroups.com 
  Sent: Saturday, January 24, 2009 5:12 PM
  Subject: [yamahacs80] CS80 1271 back on duty...


  Dear CS-80 friends,

  just want to report that my CS-80 no. 1271 has been successfully 
  resurrected. I bought it 8 years ago from a guy in switzerland who had 
  it sitting around probably more than 20 years without any service in 
  his garage. Shame on me, I found no time earlier to take care of this 
  baby, but now it plays like new again!

  Needless to say, I am pretty impressed by the quality and depth of its 
  sound when fully calibrated to factory specs.

  Since this was my first CS80 to take care of, let me share my 
  experiences when going through the complete tuning procedure:

  1) Some Keys had no velocity: First I suspected some damaged 4000 chips 
  and started swapping these on the TSB boards- until i noticed that the 
  reason was actually some bend metal contacts on the Key sensors, grrr! 
  Re-aligning the contacts helped immediately. 

  2)Following the tuning procedure I stucked quite early because the 
  voltages on the KAS board seemed way off what should be right and could 
  not be adjusted with the VR trimmers to factory spec. It took me quite 
  some time to realize that I was using the wrong ground for this 
  measurement, I took electrical ground straight from the PSU- but when 
  taking the ground directly from KAS board it read out the proper 
  Voltages perfectly. So from then, I always pick up ground from the card 
  I am working on, not the PSU ground.

  3) Pitchbend did not work: Changed CA3140 on BA board

  4) Reference tuning Voltage on KAS board dropped from 4 Volts to 0 
  Volts suddenly: Broken TR29 on BA board.

  5) Reference tuning voltage on KAS board suddenly went to 8 Volts: 
  Broken 4069 clock

  6) enevelopes sounds different for VCA and VCF on each Voice, and some 
  Voices had no attack at all. First I suspected some broken ENV chip 
  here. The complete alignement of the envelopes is a quite elaborate 
  procedure. I had to buy a digital oscilloscope for it and go thru the 
  procedure several times, but finally everything could be adjusted 
  without the need of exchanging ENV chips.

  7) Output level of Voice cards was different for each voice. Adjusting 
  the levels to factory specs (VCA gain should be 80mV) resulted in a 
  very low general output level, so I suspect this value is wrong. I just 
  increased the level up to 200-300mV, just before it starts clipping the 
  chorus and ensemble section. Now the output is much hotter and SN ratio 
  of Effect section much better.

  8) Effect section: The adjustment procedure for the chorus and ensemble 
  section seemed not to work well on my particular unit, so I adjusted 
  this by ear to a minimum of noise and a reasonable effect level, 
  skipping the specified values here.

  9) Tuning of Voice boards: Looking on my Voice boards I found no 
  temperature compensation diode, it is printed on the board but not 
  fitted. But tuning my unit was quite easy finally, after completing the 
  tuning procedure it is in tune immediately when switched on and stays 
  like this pretty well. It seems I have some magic VCOs...

  Now the only issue left is to replace a bulb in on of the program 
  buttons, but this should be not a big problem,

  cheers, Gregor



   

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

Hi Stephen,

I did it like this with quite satisfying results:

- take out OE board
- dial up a plain single sine wave voice (just one voice!)and keep it 
pressed at B4.
- turn VR3, VR4, VR5 and VR6 to "zero", I do not remember if it was 
clockwise or counterclockwise, have a try. These pots seem to control 
the amount of each delay line of the chorus effect
- listen to output via headphone and switch on chorus effect
- now turn VR3 slowly up, you will notice some increasing chorus 
effect on left or right side. Turn up until the effect is strongly 
audible
- now adjust VR7 pot and listen what happens. Depending on the 
positio of VR7, noises and artifacts can be heard. Adjust the pot 
until noise and artefacts are at a minimum level.
- Adjust VR3 again and find a level where chorus effect sounds just 
right (not too much but not to low)

Repeat procedure with VR4 and VR8, VR5 and VR9, VR6 and VR10 in pairs.

Hope that helps, good luck,

Gregor


--- In yamahacs80@yahoogroups.com, "Wavecomputer360" 
<wavecomputer360@...> wrote:
>
> Hi Will,
> 
> congratulations! I should adjust the Chorus/Tremolo section of 
mine, too. Any advice how to do it? Any caveats? I wouldn´t want to 
haul my CS around just for that minor bit of surgery...
> 
> Stephen
> 
> ____________________________________________________________________
> 
> "Ambition makes you look pretty ugly, kicking squealing Gucci 
little piggy." (Thom Yorke/Radiohead -- "Paranoid Android") 
> 
> Stephen Parsick live in concert: Bochum Planetarium (Germany), 13th 
of December, 2008, 08:00 pm.
> 
> Finally available: Stephen Parsick -- Traces of the Past Redux, 
reissued with three previously unreleased bonus tracks. For more info 
please check www.parsick.com
> 
> For legal downloads please check:
> 
> http://www.musiczeit.com/directory.php?
artist=296&title=Stephen+Parsick
> 
> 
>   ----- Original Message ----- 
>   From: willgregori 
>   To: yamahacs80@yahoogroups.com 
>   Sent: Saturday, January 24, 2009 5:12 PM
>   Subject: [yamahacs80] CS80 1271 back on duty...
> 
> 
>   Dear CS-80 friends,
> 
>   just want to report that my CS-80 no. 1271 has been successfully 
>   resurrected. I bought it 8 years ago from a guy in switzerland 
who had 
>   it sitting around probably more than 20 years without any service 
in 
>   his garage. Shame on me, I found no time earlier to take care of 
this 
>   baby, but now it plays like new again!
> 
>   Needless to say, I am pretty impressed by the quality and depth 
of its 
>   sound when fully calibrated to factory specs.
> 
>   Since this was my first CS80 to take care of, let me share my 
>   experiences when going through the complete tuning procedure:
> 
>   1) Some Keys had no velocity: First I suspected some damaged 4000 
chips 
>   and started swapping these on the TSB boards- until i noticed 
that the 
>   reason was actually some bend metal contacts on the Key sensors, 
grrr! 
>   Re-aligning the contacts helped immediately. 
> 
>   2)Following the tuning procedure I stucked quite early because 
the 
>   voltages on the KAS board seemed way off what should be right and 
could 
>   not be adjusted with the VR trimmers to factory spec. It took me 
quite 
>   some time to realize that I was using the wrong ground for this 
>   measurement, I took electrical ground straight from the PSU- but 
when 
>   taking the ground directly from KAS board it read out the proper 
>   Voltages perfectly. So from then, I always pick up ground from 
the card 
>   I am working on, not the PSU ground.
> 
>   3) Pitchbend did not work: Changed CA3140 on BA board
> 
>   4) Reference tuning Voltage on KAS board dropped from 4 Volts to 
0 
>   Volts suddenly: Broken TR29 on BA board.
> 
>   5) Reference tuning voltage on KAS board suddenly went to 8 
Volts: 
>   Broken 4069 clock
> 
>   6) enevelopes sounds different for VCA and VCF on each Voice, and 
some 
>   Voices had no attack at all. First I suspected some broken ENV 
chip 
>   here. The complete alignement of the envelopes is a quite 
elaborate 
>   procedure. I had to buy a digital oscilloscope for it and go thru 
the 
>   procedure several times, but finally everything could be adjusted 
>   without the need of exchanging ENV chips.
> 
>   7) Output level of Voice cards was different for each voice. 
Adjusting 
>   the levels to factory specs (VCA gain should be 80mV) resulted in 
a 
>   very low general output level, so I suspect this value is wrong. 
I just 
>   increased the level up to 200-300mV, just before it starts 
clipping the 
>   chorus and ensemble section. Now the output is much hotter and SN 
ratio 
>   of Effect section much better.
> 
>   8) Effect section: The adjustment procedure for the chorus and 
ensemble 
>   section seemed not to work well on my particular unit, so I 
adjusted 
>   this by ear to a minimum of noise and a reasonable effect level, 
>   skipping the specified values here.
> 
>   9) Tuning of Voice boards: Looking on my Voice boards I found no 
>   temperature compensation diode, it is printed on the board but 
not 
>   fitted. But tuning my unit was quite easy finally, after 
completing the 
>   tuning procedure it is in tune immediately when switched on and 
stays 

>   like this pretty well. It seems I have some magic VCOs...
> 
>   Now the only issue left is to replace a bulb in on of the program 
>   buttons, but this should be not a big problem,
> 
>   cheers, Gregor
> 
> 
> 
>    
> 
> [Non-text portions of this message have been removed]
>

Thanks for all the alignment tips!

I was thinking, did you check the signal when you raise the "keyboard-
control" levers to max. I can imagine this can result in clipping the 
chorus section.
I tried to adjust the chorus/tremelo-section too some time ago, to 
minimize noise. I found it very difficult to find the sweet spot (I 
played chords since this raises the level). The clock-setting is very 
critical. The vca-levels are critical since clipping will result.
I have to admit, I never use the chorus/tremelo since I don't like the 
sound of it.

--- In yamahacs80@yahoogroups.com, "willgregori" <will.gregory@...> 
wrote:
> 7) Output level of Voice cards was different for each voice. 
Adjusting 
> the levels to factory specs (VCA gain should be 80mV) resulted in a 
> very low general output level, so I suspect this value is wrong. I 
just 
> increased the level up to 200-300mV, just before it starts clipping 
the 
> chorus and ensemble section. Now the output is much hotter and SN 
ratio 
> of Effect section much better.

you are right, if you tweak my unit long enough you will find some 
settings where it is possible to clip the chorus section. However, in 
99% of my daily work settings it does not clip, so I do not care 
about that too much. Even if it clips, I just reduce the output level 
of the patches but enjoy a more cleaner effect in most cases.

I agree it is somehow fiddly to find the right trimmer settings, but 
for me it was worth the effort.  I believe the chorus/tremolo adds 
quite some character to some sounds if used subtle and gives a nice 
stereo effect.

--- In yamahacs80@yahoogroups.com, "erikfromhere" <moogsynthex@...> 
wrote:
>
> I was thinking, did you check the signal when you raise 
the "keyboard-
> control" levers to max. I can imagine this can result in clipping 
the 
> chorus section.
> I tried to adjust the chorus/tremelo-section too some time ago, to 
> minimize noise. I found it very difficult to find the sweet spot (I 
> played chords since this raises the level). The clock-setting is 
very 
> critical. The vca-levels are critical since clipping will result.
> I have to admit, I never use the chorus/tremelo since I don't like 
the 
> sound of it.
> 
> --- In yamahacs80@yahoogroups.com, "willgregori" <will.gregory@> 
> wrote:
> > 7) Output level of Voice cards was different for each voice. 
> Adjusting 
> > the levels to factory specs (VCA gain should be 80mV) resulted in 
a 
> > very low general output level, so I suspect this value is wrong. 
I 
> just 
> > increased the level up to 200-300mV, just before it starts 
clipping 

> the 
> > chorus and ensemble section. Now the output is much hotter and SN 
> ratio 
> > of Effect section much better.
>