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CMOS FILTER CGS49

2012-12-31 by robert

Hello,

I am having a problem with the CMOS filter. The frequency pot on either of the filters has no effect. The CV's input also have no effect. I have set the trimmers to the minimum setting and still no effect. A saw tooth wave at the input gives a saw wave at the HP and Notch but nothing at the LP or BP. The distortion gives the desired effect of turning the saw into a distorted saw on the scope. The voltages are all good + - 15 and -5 are at all the correct spots. Both sides of the Dual filter behave the same way?

Any ideas what may be wrong? I have tried the frequency pot (CW and CCW) set at O /+15 and -15/+15 doesn't make any difference.

Thanks
Robert Gerard

Re: CMOS FILTER CGS49

2012-12-31 by sasami@hotkey.net.au

It is probably a construction error cause by missidentified parts - the sort
of thing that would cayse the same mistake to be made twice. Check that you
have the correct transistors in each expo converter. There is an NPN an a
pair of PNP in each. Get one in the wrong spot, and it won't work. Also
check power directly at the chip's power pins. Make sure any CV or pot
change results in a voltage change at Pin 1 of the corresponding TL072.
Check you haven't cooked your LM3080s.

Ken

Show quoted textHide quoted text

>Hello,
>
>I am having a problem with the CMOS filter. The frequency pot on either of

the filters has no effect. The CV's input also have no effect. I have set
the trimmers to the minimum setting and still no effect. A saw tooth wave at
the input gives a saw wave at the HP and Notch but nothing at the LP or BP.
The distortion gives the desired effect of turning the saw into a distorted
saw on the scope. The voltages are all good + - 15 and -5 are at all the
correct spots. Both sides of the Dual filter behave the same way?

>
>Any ideas what may be wrong? I have tried the frequency pot (CW and CCW)

set at O /+15 and -15/+15 doesn't make any difference.

>
>Thanks
>Robert Gerard
>
>
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>

_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: CMOS FILTER CGS49

2013-01-01 by robert

Hi Ken,

Thanks for your quick reply.
I checked and rechecked all the components and I don't see any mistakes.
Each section has two 557 transistors and one 547 transistor. I went with the orientation on the silk screen which is what is in the schematic. All the voltages components check as to the schematic.

The frequency pot is a 100K set between +15 and -15. I added the 150K resistor inline with the wiper. The voltage at pin 1 of the TL072 varies between -.13 and +.13 depending on the pot settings. The Voltage at pins 5 of the 3080 is -5 (on both) with -2 at pin 6.

I switched the TL072 to no effect. Note that the voltage on the pot after the 150K res is +/- 6 depending on the pot poss.

I get a signal out of the module very low for LP and HP ( about .1v) and higher for BP and Notch (about 5v), the distortion works. but the frequency pot has no effect.

What is the CVSN for ? I did not connect it as I assumed it was optional for centring the freq pot.

Any ideas?
Robert

Show quoted textHide quoted text

--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> It is probably a construction error cause by missidentified parts - the sort
> of thing that would cayse the same mistake to be made twice. Check that you
> have the correct transistors in each expo converter. There is an NPN an a
> pair of PNP in each. Get one in the wrong spot, and it won't work. Also
> check power directly at the chip's power pins. Make sure any CV or pot
> change results in a voltage change at Pin 1 of the corresponding TL072.
> Check you haven't cooked your LM3080s.
>
> Ken
>
> >Hello,
> >
> >I am having a problem with the CMOS filter. The frequency pot on either of
> the filters has no effect. The CV's input also have no effect. I have set
> the trimmers to the minimum setting and still no effect. A saw tooth wave at
> the input gives a saw wave at the HP and Notch but nothing at the LP or BP.
> The distortion gives the desired effect of turning the saw into a distorted
> saw on the scope. The voltages are all good + - 15 and -5 are at all the
> correct spots. Both sides of the Dual filter behave the same way?
> >
> >Any ideas what may be wrong? I have tried the frequency pot (CW and CCW)
> set at O /+15 and -15/+15 doesn't make any difference.
> >
> >Thanks
> >Robert Gerard
> >
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>

Re: CMOS FILTER CGS49

2013-01-01 by robert

Show quoted textHide quoted text

--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> It is probably a construction error cause by missidentified parts - the sort
> of thing that would cayse the same mistake to be made twice. Check that you
> have the correct transistors in each expo converter. There is an NPN an a
> pair of PNP in each. Get one in the wrong spot, and it won't work. Also
> check power directly at the chip's power pins. Make sure any CV or pot
> change results in a voltage change at Pin 1 of the corresponding TL072.
> Check you haven't cooked your LM3080s.
>
> Ken
>
> >Hello,
> >
> >I am having a problem with the CMOS filter. The frequency pot on either of
> the filters has no effect. The CV's input also have no effect. I have set
> the trimmers to the minimum setting and still no effect. A saw tooth wave at
> the input gives a saw wave at the HP and Notch but nothing at the LP or BP.
> The distortion gives the desired effect of turning the saw into a distorted
> saw on the scope. The voltages are all good + - 15 and -5 are at all the
> correct spots. Both sides of the Dual filter behave the same way?
> >
> >Any ideas what may be wrong? I have tried the frequency pot (CW and CCW)
> set at O /+15 and -15/+15 doesn't make any difference.
> >
> >Thanks
> >Robert Gerard
> >
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>

Re: CMOS FILTER CGS49

2013-01-01 by sasami@hotkey.net.au

>What is the CVSN for ? I did not connect it as I assumed it was optional

for centring the freq pot.

Control Voltage Summing Node. It is a point where more inputs can be added
via extra resistors.

>Any ideas?

Did you swap out the LM3080? Is the CMOS chip OK? Is it the unbuffered (UB)
variant?

If everything is right, it should work.

Ken
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: CMOS FILTER CGS49

2013-01-01 by robert

Yes its the CD UB variant, Is there an easy way to test the LM3080? I got mine from LB designs, I cant imagine they are all bad?

What should the voltages be on the LM3080 typically be? Pin 5 is at -5 and turning the freq pot all the way it only drops to like -4.9?

I am sure I have made some stupid error???

Robert

Show quoted textHide quoted text

--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
>
> >What is the CVSN for ? I did not connect it as I assumed it was optional
> for centring the freq pot.
>
> Control Voltage Summing Node. It is a point where more inputs can be added
> via extra resistors.
>
> >Any ideas?
>
> Did you swap out the LM3080? Is the CMOS chip OK? Is it the unbuffered (UB)
> variant?
>
> If everything is right, it should work.
>
> Ken
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>

Re: CMOS FILTER CGS49

2013-01-01 by sasami@hotkey.net.au

>Yes its the CD UB variant, Is there an easy way to test the LM3080? I got

mine from LB designs, I cant imagine they are all bad?

I'm just looking for something wrong in both sections.

>What should the voltages be on the LM3080 typically be? Pin 5 is at -5 and

turning the freq pot all the way it only drops to like -4.9?

Pin 5 is tied via an internal diode to the negative power pin. It won't
move, voltage wise. It is the current through it that controls it.

Take a couple of high-res photos of the thing - above and below.

Ken
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: CMOS FILTER CGS49

2013-01-01 by robert

I posted two pictures in the album called CMOS, If they are not big enough let me know if I can e-mail them to you.

THanks, Robert

Show quoted textHide quoted text

--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> >Yes its the CD UB variant, Is there an easy way to test the LM3080? I got
> mine from LB designs, I cant imagine they are all bad?
>
> I'm just looking for something wrong in both sections.
>
> >What should the voltages be on the LM3080 typically be? Pin 5 is at -5 and
> turning the freq pot all the way it only drops to like -4.9?
>
> Pin 5 is tied via an internal diode to the negative power pin. It won't
> move, voltage wise. It is the current through it that controls it.
>
> Take a couple of high-res photos of the thing - above and below.
>
> Ken
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>

Re: CMOS FILTER CGS49

2013-01-02 by sasami@hotkey.net.au

I can't see anything wrong in what you have uploaded. Have you got all the
links in at the other end of the board?

Ken

Show quoted textHide quoted text

>
>I posted two pictures in the album called CMOS, If they are not big enough

let me know if I can e-mail them to you.

>
>THanks, Robert
>
>
>--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>>
>> >Yes its the CD UB variant, Is there an easy way to test the LM3080? I got
>> mine from LB designs, I cant imagine they are all bad?
>>
>> I'm just looking for something wrong in both sections.
>>
>> >What should the voltages be on the LM3080 typically be? Pin 5 is at -5 and
>> turning the freq pot all the way it only drops to like -4.9?
>>
>> Pin 5 is tied via an internal diode to the negative power pin. It won't
>> move, voltage wise. It is the current through it that controls it.
>>
>> Take a couple of high-res photos of the thing - above and below.
>>
>> Ken
>> _______________________________________________________________________
>> Ken Stone sasami@... otherunicorn@...
>> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>>
>
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>

Re: CMOS FILTER CGS49

2013-01-02 by robert

I put in 10 links (jumpers) Five in each filter.
Hope I didn't miss some.

Robert

Show quoted textHide quoted text

--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> I can't see anything wrong in what you have uploaded. Have you got all the
> links in at the other end of the board?
>
> Ken
>
> >
> >I posted two pictures in the album called CMOS, If they are not big enough
> let me know if I can e-mail them to you.
> >
> >THanks, Robert
> >
> >
> >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >>
> >> >Yes its the CD UB variant, Is there an easy way to test the LM3080? I got
> >> mine from LB designs, I cant imagine they are all bad?
> >>
> >> I'm just looking for something wrong in both sections.
> >>
> >> >What should the voltages be on the LM3080 typically be? Pin 5 is at -5 and
> >> turning the freq pot all the way it only drops to like -4.9?
> >>
> >> Pin 5 is tied via an internal diode to the negative power pin. It won't
> >> move, voltage wise. It is the current through it that controls it.
> >>
> >> Take a couple of high-res photos of the thing - above and below.
> >>
> >> Ken
> >> _______________________________________________________________________
> >> Ken Stone sasami@ otherunicorn@
> >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>

Re: CMOS FILTER CGS49

2013-01-02 by sasami@hotkey.net.au

The only remaining think I can think of is for you to send it to me.

Ken

Show quoted textHide quoted text

>
>I put in 10 links (jumpers) Five in each filter.
>Hope I didn't miss some.
>
>Robert
>
>--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>>
>> I can't see anything wrong in what you have uploaded. Have you got all the
>> links in at the other end of the board?
>>
>> Ken
>>
>> >
>> >I posted two pictures in the album called CMOS, If they are not big enough
>> let me know if I can e-mail them to you.
>> >
>> >THanks, Robert
>> >
>> >
>> >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
>> >>
>> >> >Yes its the CD UB variant, Is there an easy way to test the LM3080? I got
>> >> mine from LB designs, I cant imagine they are all bad?
>> >>
>> >> I'm just looking for something wrong in both sections.
>> >>
>> >> >What should the voltages be on the LM3080 typically be? Pin 5 is at

-5 and

>> >> turning the freq pot all the way it only drops to like -4.9?
>> >>
>> >> Pin 5 is tied via an internal diode to the negative power pin. It won't
>> >> move, voltage wise. It is the current through it that controls it.
>> >>
>> >> Take a couple of high-res photos of the thing - above and below.
>> >>
>> >> Ken
>> >> _______________________________________________________________________
>> >> Ken Stone sasami@ otherunicorn@
>> >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> >> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>> >>
>> >
>> >
>> >
>> >
>> >------------------------------------
>> >
>> >The CGS Modular Synth home page: http://www.cgs.synth.net/
>> >Yahoo! Groups Links
>> >
>> >
>> >
>> >
>> _______________________________________________________________________
>> Ken Stone sasami@... otherunicorn@...
>> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>>
>
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>

Re: CMOS FILTER CGS49

2013-01-02 by robert

Hi,

As a last ditch attempt, I found a 3080 (metal can type) and replaced one on the board! Hey it works now In the Notch Hp and BP modes, I think the other 3080 goes to the LP which still does not work but I don't have a replacement for it! Now all I have to do is find three more 3080's hahaha.

Thanks ever so much for your suggestions. This is the first time in many years of building circuits that I have had a bad part, let alone four!

Thanks

Robert Gerard

Show quoted textHide quoted text

--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> The only remaining think I can think of is for you to send it to me.
>
> Ken
>
> >
> >I put in 10 links (jumpers) Five in each filter.
> >Hope I didn't miss some.
> >
> >Robert
> >
> >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >>
> >> I can't see anything wrong in what you have uploaded. Have you got all the
> >> links in at the other end of the board?
> >>
> >> Ken
> >>
> >> >
> >> >I posted two pictures in the album called CMOS, If they are not big enough
> >> let me know if I can e-mail them to you.
> >> >
> >> >THanks, Robert
> >> >
> >> >
> >> >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> >>
> >> >> >Yes its the CD UB variant, Is there an easy way to test the LM3080? I got
> >> >> mine from LB designs, I cant imagine they are all bad?
> >> >>
> >> >> I'm just looking for something wrong in both sections.
> >> >>
> >> >> >What should the voltages be on the LM3080 typically be? Pin 5 is at
> -5 and
> >> >> turning the freq pot all the way it only drops to like -4.9?
> >> >>
> >> >> Pin 5 is tied via an internal diode to the negative power pin. It won't
> >> >> move, voltage wise. It is the current through it that controls it.
> >> >>
> >> >> Take a couple of high-res photos of the thing - above and below.
> >> >>
> >> >> Ken
> >> >> _______________________________________________________________________
> >> >> Ken Stone sasami@ otherunicorn@
> >> >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> >> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> >> >>
> >> >
> >> >
> >> >
> >> >
> >> >------------------------------------
> >> >
> >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> >Yahoo! Groups Links
> >> >
> >> >
> >> >
> >> >
> >> _______________________________________________________________________
> >> Ken Stone sasami@ otherunicorn@
> >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>

Cgs synth

CMOS FILTER CGS49

CMOS FILTER CGS49

Re: CMOS FILTER CGS49

Re: CMOS FILTER CGS49

Re: CMOS FILTER CGS49

Re: CMOS FILTER CGS49

Re: CMOS FILTER CGS49

Re: CMOS FILTER CGS49

Re: CMOS FILTER CGS49

Re: CMOS FILTER CGS49

Re: CMOS FILTER CGS49

Re: CMOS FILTER CGS49

Re: CMOS FILTER CGS49

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