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First message/some CS80 questions

First message/some CS80 questions

2008-10-06 by maxferfranc

Hi all, this is my first message here: I'm thrilled by analog circuits 
although I'm not an expert, so I'm studying the Yamaha CS80 to try and 
make some sort of virtual, as I'm not satisfied with the Arturia.

I would ask you some questions to the people here who knows more than 
me about reading schematics

First question: if you look at the picture I posted there

http://f1.grp.yahoofs.com/v1/YIrqSApHmjS6cA3dqhZH-
GmV76P2YcikZA_XszBHjYyz7poNC3SZztKSOwD4kC4LWbNppnry_1movZzpGN2mUqumJOKHG
p_Ipg/CS80%20schems/tws.jpg

You will see the velocity generator in Yamaha CS80: I'd like to know 
this: what is the FET doing here? And, what is the output of 
the "Initial touch"? Is it a decay envelope? How does it link to a 
supposed variable gate velocity?

Now look here

http://f1.grp.yahoofs.com/v1/YIrqSFqjXlS6cA3dBH1N34CSLYoZ5oUQzDqtOY18kaL
q4napy2NIUcZliGnwlKUQlnbxNbPxLmA0pd3mVL77desKCsG_EsLsbQ/CS80%
20schems/41%2520-%2520M%2520Circuit%2520Diagram.bmp

You will see that I highlighted in red two resistors, one set at 100k 
to the HPF and the other set at 47k : do these resistors act as CV 
limiters? And what is more limited, the HPF or the LPF?

Hope these questions are not too hard, thx for any reply

Re: First message/some CS80 questions

2008-10-06 by paintingwithsound

You can look at the FET as a switch. It appears to be turned on very
briefly by the key gate into a decaying sample and hold which should
give a very fast rise to the AT level followed by a decay set by the
10M resistor & cap.

As far as the two different resistors goes they are probably balancing
the two filters and if you look at the resistors labled R6 & R7 with
no value they are probably for fine calibration.


--- In vintagesynthrepair@yahoogroups.com, "maxferfranc"
<faxiomas@...> wrote:
Show quoted textHide quoted text
>
> Hi all, this is my first message here: I'm thrilled by analog circuits 
> although I'm not an expert, so I'm studying the Yamaha CS80 to try and 
> make some sort of virtual, as I'm not satisfied with the Arturia.
> 
> I would ask you some questions to the people here who knows more than 
> me about reading schematics
> 
> First question: if you look at the picture I posted there
> 
> http://f1.grp.yahoofs.com/v1/YIrqSApHmjS6cA3dqhZH-
> GmV76P2YcikZA_XszBHjYyz7poNC3SZztKSOwD4kC4LWbNppnry_1movZzpGN2mUqumJOKHG
> p_Ipg/CS80%20schems/tws.jpg
> 
> You will see the velocity generator in Yamaha CS80: I'd like to know 
> this: what is the FET doing here? And, what is the output of 
> the "Initial touch"? Is it a decay envelope? How does it link to a 
> supposed variable gate velocity?
> 
> Now look here
> 
> http://f1.grp.yahoofs.com/v1/YIrqSFqjXlS6cA3dBH1N34CSLYoZ5oUQzDqtOY18kaL
> q4napy2NIUcZliGnwlKUQlnbxNbPxLmA0pd3mVL77desKCsG_EsLsbQ/CS80%
> 20schems/41%2520-%2520M%2520Circuit%2520Diagram.bmp
> 
> You will see that I highlighted in red two resistors, one set at 100k 
> to the HPF and the other set at 47k : do these resistors act as CV 
> limiters? And what is more limited, the HPF or the LPF?
> 
> Hope these questions are not too hard, thx for any reply
>

Re: [vintagesynthrepair] First message/some CS80 questions

2008-10-07 by Roy J. Tellason

On Monday 06 October 2008 18:33, maxferfranc wrote:
> Hi all, this is my first message here: I'm thrilled by analog circuits
> although I'm not an expert, so I'm studying the Yamaha CS80 to try and
> make some sort of virtual, as I'm not satisfied with the Arturia.
>
> I would ask you some questions to the people here who knows more than
> me about reading schematics
>
> First question: if you look at the picture I posted there
>
> http://f1.grp.yahoofs.com/v1/YIrqSApHmjS6cA3dqhZH-
> GmV76P2YcikZA_XszBHjYyz7poNC3SZztKSOwD4kC4LWbNppnry_1movZzpGN2mUqumJOKHG
> p_Ipg/CS80%20schems/tws.jpg

That link won't work -- it's one of those temporary URLs that Yahoo generates 
that lasts no longer than the session you're in.   You need to find out what 
group,  and build it from there,  to point to the specific file.  Dunno why 
they do that,  but it seems to trip a lot of people up,  over and over 
again...

(Snip)
> http://f1.grp.yahoofs.com/v1/YIrqSFqjXlS6cA3dBH1N34CSLYoZ5oUQzDqtOY18kaL
> q4napy2NIUcZliGnwlKUQlnbxNbPxLmA0pd3mVL77desKCsG_EsLsbQ/CS80%
> 20schems/41%2520-%2520M%2520Circuit%2520Diagram.bmp

Same thing with this one,  it won't work.


-- 
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space,  a critter that can
be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James 
M Dakin

Re: [vintagesynthrepair] First message/some CS80 questions

2008-10-07 by Max Fazio

Don't mind the links, they are on the files section of the group...anyway thx for you care!
M
Show quoted textHide quoted text
----- Original Message -----
Sent: Tuesday, October 07, 2008 2:10 AM
Subject: Re: [vintagesynthrepair] First message/some CS80 questions

On Monday 06 October 2008 18:33, maxferfranc wrote:
> Hi all, this is my first message here: I'm thrilled by analog circuits
> although I'm not an expert, so I'm studying the Yamaha CS80 to try and
> make some sort of virtual, as I'm not satisfied with the Arturia.
>
> I would ask you some questions to the people here who knows more than
> me about reading schematics
>
> First question: if you look at the picture I posted there
>
> http://f1.grp.yahoofs.com/v1/YIrqSApHmjS6cA3dqhZH-
> GmV76P2YcikZA_XszBHjYyz7poNC3SZztKSOwD4kC4LWbNppnry_1movZzpGN2mUqumJOKHG
> p_Ipg/CS80%20schems/tws.jpg

That link won't work -- it's one of those temporary URLs that Yahoo generates
that lasts no longer than the session you're in. You need to find out what
group, and build it from there, to point to the specific file. Dunno why
they do that, but it seems to trip a lot of people up, over and over
again...

(Snip)
> http://f1.grp.yahoofs.com/v1/YIrqSFqjXlS6cA3dBH1N34CSLYoZ5oUQzDqtOY18kaL
> q4napy2NIUcZliGnwlKUQlnbxNbPxLmA0pd3mVL77desKCsG_EsLsbQ/CS80%
> 20schems/41%2520-%2520M%2520Circuit%2520Diagram.bmp

Same thing with this one, it won't work.

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

Re: [vintagesynthrepair] Re: First message/some CS80 questions

2008-10-07 by Max Fazio

Great! Thx a lot: I can see it like a complex decay envelope! It0s the first time that someone gave me this clear explaination...
Also, how is the envelope signal "limited" by the two resistors highlighted in red? My idea is that the CV from the envelope is clipped or multiplied until around half the range of the LPF, am I wrong?
Thx again!
Show quoted textHide quoted text
----- Original Message -----
Sent: Tuesday, October 07, 2008 12:56 AM
Subject: [vintagesynthrepair] Re: First message/some CS80 questions

You can look at the FET as a switch. It appears to be turned on very
briefly by the key gate into a decaying sample and hold which should
give a very fast rise to the AT level followed by a decay set by the
10M resistor & cap.

As far as the two different resistors goes they are probably balancing
the two filters and if you look at the resistors labled R6 & R7 with
no value they are probably for fine calibration.

--- In vintagesynthrepair@yahoogroups.com, "maxferfranc"
.> wrote:
>
> Hi all, this is my first message here: I'm thrilled by analog circuits
> although I'm not an expert, so I'm studying the Yamaha CS80 to try and
> make some sort of virtual, as I'm not satisfied with the Arturia.
>
> I would ask you some questions to the people here who knows more than
> me about reading schematics
>
>; First question: if you look at the picture I posted there
>
> http://f1.grp.yahoofs.com/v1/YIrqSApHmjS6cA3dqhZH-
> GmV76P2YcikZA_XszBHjYyz7poNC3SZztKSOwD4kC4LWbNppnry_1movZzpGN2mUqumJOKHG
> p_Ipg/CS80%20schems/tws.jpg
>
> You will see the velocity generator in Yamaha CS80: I'd like to know
> this: what is the FET doing here? And, what is the output of
> the "Initial touch"? Is it a decay envelope? How does it link to a
> supposed variable gate velocity?
>
> Now look here
>
> http://f1.grp.yahoofs.com/v1/YIrqSFqjXlS6cA3dBH1N34CSLYoZ5oUQzDqtOY18kaL
> q4napy2NIUcZliGnwlKUQlnbxNbPxLmA0pd3mVL77desKCsG_EsLsbQ/CS80%
> 20schems/41%2520-%2520M%2520Circuit%2520Diagram.bmp
>
> You will see that I highlighted in red two resistors, one set at 100k
> to the HPF and the other set at 47k : do these resistors act as CV
> limiters? And what is more limited, the HPF or the LPF?
>
> Hope these questions are not too hard, thx for any reply
>

Re: [vintagesynthrepair] Re: First message/some CS80 questions

2008-10-07 by Max Fazio

Hi
Just a need tomake a thing clear on this velocity waveform: could you see if the cap+resistors output just the "envelope amount" in this waveform or is it supposedly dirving the "decay" time?
;
Thx!
Max
Show quoted textHide quoted text
----- Original Message -----
Sent: Tuesday, October 07, 2008 12:56 AM
Subject: [vintagesynthrepair] Re: First message/some CS80 questions

You can look at the FET as a switch. It appears to be turned on very
briefly by the key gate into a decaying sample and hold which should
give a very fast rise to the AT level followed by a decay set by the
10M resistor & cap.

As far as the two different resistors goes they are probably balancing
the two filters and if you look at the resistors labled R6 & R7 with
no value they are probably for fine calibration.

--- In vintagesynthrepair@yahoogroups.com, "maxferfranc"
.> wrote:
>
> Hi all, this is my first message here: I'm thrilled by analog circuits
> although I'm not an expert, so I'm studying the Yamaha CS80 to try and
> make some sort of virtual, as I'm not satisfied with the Arturia.
>;
> I would ask you some questions to the people here who knows more than
> me about reading schematics
>
> First question: if you look at the picture I posted there
>
> http://f1.grp.yahoofs.com/v1/YIrqSApHmjS6cA3dqhZH-
> GmV76P2YcikZA_XszBHjYyz7poNC3SZztKSOwD4kC4LWbNppnry_1movZzpGN2mUqumJOKHG
> p_Ipg/CS80%20schems/tws.jpg
>
> You will see the velocity generator in Yamaha CS80: I'd like to know
> this: what is the FET doing here? And, what is the output of
> the "Initial touch"? Is it a decay envelope? How does it link to a
> supposed variable gate velocity?
>
> Now look here
>
> http://f1.grp.yahoofs.com/v1/YIrqSFqjXlS6cA3dBH1N34CSLYoZ5oUQzDqtOY18kaL
> q4napy2NIUcZliGnwlKUQlnbxNbPxLmA0pd3mVL77desKCsG_EsLsbQ/CS80%
> 20schems/41%2520-%2520M%2520Circuit%2520Diagram.bmp
>
> You will see that I highlighted in red two resistors, one set at 100k
> to the HPF and the other set at 47k : do these resistors act as CV
> limiters? And what is more limited, the HPF or the LPF?
>
> Hope these questions are not too hard, thx for any reply
>

Oberheim ob3

2008-10-09 by Sean Carter



Im trying to fix and oberheim ob3 does anyone know how to get a schematic for them? This think wont even power up, so im not sure what to do first.

Thanks
Sean


Re: Oberheim ob3

2008-10-09 by Michael Kirk

Can't help with a schematic, but with no power...

1) Check mains voltage at transformer, switch OK, fuse OK?
2) Check DC supply voltages inside, replace any old filter capacitors.
3) Check supply voltages at chips.
4) With power off, reseat any socketed parts and power up again.

Others may have more specific troubleshooting ideas.  These are pretty
general.

-Mike


--- In vintagesynthrepair@yahoogroups.com, Sean Carter
<seancarter777@...> wrote:
>
> 
> 
> Im trying to fix and oberheim ob3 does anyone know how to get a
schematic
> for them? This think wont even power up, so im not sure what to do
first.
Show quoted textHide quoted text
> 
> Thanks
> Sean
>

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