Analogue systems

Hello,

I've noticed on several occasions that the clock of my RS-200 is far from rock steady...
Small but obvious speed variations appear from time to time, and it has been doing this since I bought it new more than a year ago...independent of whatever modules are plugged in the same RS-15 case (current consumption cannot be an issue with so few modules in the case and all other modules do function properly).

Also, during the past week, the CV outputs A, B and C produced some seriously drifting CVs...
This problem seems now to have disappeared or to be attenuated in a way it is barely noticeable, for whatever reason... I don't know why or how it appeared in the first place ?!

Last year, during the very hot summer days, the sequencer stopped running after some time...no way to get it running again but after the modular was shut down for while...
Perhaps some heat dissipation problem...I e-mailed Bob about it and at the moment I decided to send it out for revision, it started working properly again... just like it "felt" I was going to send it out and it was afraid to undergo an "operation" :-)

Anyone experiencing similar problems or is my module a monday morning assembly ?
Definitely a ghost in the machine...

Thanks

I have an RS40 whose clock drifts quite a bit (I've also noticed that it's sample and held output drifts upwards too). I suspect it's the same clock circuit as the RS200 (same min and max frequency, output levels). I haven't quite had the time to investigate properly, but I did swap out the TL072  in the clock circuit with no improvement. There are two 1u (or is it 2u2?) film caps on there which I believe are the timing caps, so those were my next port of call. I should really trace out the circuit so I can fault find it properly. My RS40 is probably two years old, maybe they had a batch of some particular part which is prone to failure. Actually now I think of it, I believe the S&H circuit uses the same type of cap for storing the sampled voltage so if they had a bad batch maybe there is a connection between the two faults... I did speak to Bob about it, he'd said he'd never heard of this particular problem before but it seems likely that we have the same issue. When I get to the bottom of it I'll let you know.

Regards,

Daniel.

To: analogue_systems@yahoogroups.com

From: coenen.olivier@skynet.be
Date: Sat, 15 Oct 2011 14:42:02 +0000
Subject: [analogue_systems] RS-200 CV & Clock drift


















 



  


    
      
      
      Hello,



I've noticed on several occasions that the clock of my RS-200 is far from rock steady...

Small but obvious speed variations appear from time to time, and it has been doing this since I bought it new more than a year ago...independent of whatever modules are plugged in the same RS-15 case (current consumption cannot be an issue with so few modules in the case and all other modules do function properly).



Also, during the past week, the CV outputs A, B and C produced some seriously drifting CVs...

This problem seems now to have disappeared or to be attenuated in a way it is barely noticeable, for whatever reason... I don't know why or how it appeared in the first place ?!



Last year, during the very hot summer days, the sequencer stopped running after some time...no way to get it running again but after the modular was shut down for while...

Perhaps some heat dissipation problem...I e-mailed Bob about it and at the moment I decided to send it out for revision, it started working properly again... just like it "felt" I was going to send it out and it was afraid to undergo an "operation" :-)



Anyone experiencing similar problems or is my module a monday morning assembly ?

Definitely a ghost in the machine...



Thanks





    
     

    
    






   		 	   		  

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

Hi Daniel,

I have an RS40 too that I use quite often and it's really precise and  
stable...
I'll keep monitoring my RS-200 and report anything strange.
Anyways, thank you for looking into this.

Cheers,

Z.

On 16 Oct 2011, at 00:30, lausome graylien Skevington wrote:

>
> I have an RS40 whose clock drifts quite a bit (I've also noticed  
> that it's sample and held output drifts upwards too). I suspect  
> it's the same clock circuit as the RS200 (same min and max  
> frequency, output levels). I haven't quite had the time to  
> investigate properly, but I did swap out the TL072  in the clock  
> circuit with no improvement. There are two 1u (or is it 2u2?) film  
> caps on there which I believe are the timing caps, so those were my  
> next port of call. I should really trace out the circuit so I can  
> fault find it properly. My RS40 is probably two years old, maybe  
> they had a batch of some particular part which is prone to failure.  
> Actually now I think of it, I believe the S&H circuit uses the same  
> type of cap for storing the sampled voltage so if they had a bad  
> batch maybe there is a connection between the two faults... I did  
> speak to Bob about it, he'd said he'd never heard of this  
> particular problem before but it seems likely that we have the same  
> issue. When I get t
>  o the bottom of it I'll let you know.
>
> Regards,
>
> Daniel.
>
> To: analogue_systems@yahoogroups.com
> From: coenen.olivier@skynet.be
> Date: Sat, 15 Oct 2011 14:42:02 +0000
> Subject: [analogue_systems] RS-200 CV & Clock drift
>
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>
>       Hello,
>
>
>
> I've noticed on several occasions that the clock of my RS-200 is  
> far from rock steady...
>
> Small but obvious speed variations appear from time to time, and it  
> has been doing this since I bought it new more than a year  
> ago...independent of whatever modules are plugged in the same RS-15  
> case (current consumption cannot be an issue with so few modules in  
> the case and all other modules do function properly).
>
>
>
> Also, during the past week, the CV outputs A, B and C produced some  
> seriously drifting CVs...
>
> This problem seems now to have disappeared or to be attenuated in a  
> way it is barely noticeable, for whatever reason... I don't know  
> why or how it appeared in the first place ?!
>
>
>
> Last year, during the very hot summer days, the sequencer stopped  
> running after some time...no way to get it running again but after  
> the modular was shut down for while...
>
> Perhaps some heat dissipation problem...I e-mailed Bob about it and  
> at the moment I decided to send it out for revision, it started  
> working properly again... just like it "felt" I was going to send  
> it out and it was afraid to undergo an "operation" :-)
>
>
>
> Anyone experiencing similar problems or is my module a monday  
> morning assembly ?
>
> Definitely a ghost in the machine...
>
>
>
> Thanks
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>    		 	   		
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

Two more suggestions:

I've only had a pot go bad once in over 10 years of owning many of Bob's modules, but a dirty or worn or otherwise slightly duff clock speed pot could be the source of your speed fluctuation rather than anything more complicated. It's easy enough to replace too.

Have you checked that the external clock input socket is clean and the normalising contacts are making good connections when no jack is inserted?


Best of luck

Sean

--- In analogue_systems@yahoogroups.com, coenen olivier <coenen.olivier@...> wrote:

>
> Hello Terje,
> 
> I know a little drift is part of the game with analogue stuff, but,  
> what I've experienced is more
> than "natural" drift caused by temperature and likes ...
> I think it is plausible that one or another component is/are beyond  
> suitable tolerance and could/should be replaced
> for better stability.
> My problem is to detect the components that might be responsible for  
> the drift...
> 
> Thanks for your input :-)
> 
> Cheers,
> 
> Z.
> 
> On 16 Oct 2011, at 17:03, Terje Winther wrote:
> 
> > > I've noticed on several occasions that the clock of my RS-200 is far
> > > from rock steady...
> > >
> > Yes, all analogue step sequencers drift a little. Not much, and I
> > think my AS-200 is fairly steady, but as you have noticed: it is not
> > rock steady like something digital.
> > Temperature, humidity and the amount of time used influence the tempo.
> >
> > Terje Winther
> > terje.winther@...
> > http://www.wintherstormer.no/
> >
> > [Non-text portions of this message have been removed]
> >
> > 
> 
> 
> 
> [Non-text portions of this message have been removed]
>

> I've noticed on several occasions that the clock of my RS-200 is far  
> from rock steady...
>
Yes, all analogue step sequencers drift a little. Not much, and I  
think my AS-200 is fairly steady, but as you have noticed: it is not  
rock steady like something digital.
Temperature, humidity and the amount of time used influence the tempo.


Terje Winther
terje.winther@wintherstormer.no
http://www.wintherstormer.no/






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

Hello Terje,

I know a little drift is part of the game with analogue stuff, but,  
what I've experienced is more
than "natural" drift caused by temperature and likes ...
I think it is plausible that one or another component is/are beyond  
suitable tolerance and could/should be replaced
for better stability.
My problem is to detect the components that might be responsible for  
the drift...

Thanks for your input :-)

Cheers,

Z.

On 16 Oct 2011, at 17:03, Terje Winther wrote:

> > I've noticed on several occasions that the clock of my RS-200 is far
> > from rock steady...
> >
> Yes, all analogue step sequencers drift a little. Not much, and I
> think my AS-200 is fairly steady, but as you have noticed: it is not
> rock steady like something digital.
> Temperature, humidity and the amount of time used influence the tempo.
>
> Terje Winther
> terje.winther@wintherstormer.no
> http://www.wintherstormer.no/
>
> [Non-text portions of this message have been removed]
>
> 



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

Thank you Sean,

That sounds like a good place to start...

As a matter of fact, the sequencer doesn't get that much use for the  
music I'm making, so the pots stay in one position for quite some  
time and the external
clock input socket isn't much used either.
So, I'll definitely take some time to check those in the first place !

Cheers,

Z.



On 16 Oct 2011, at 17:46, sean_process wrote:

> Two more suggestions:
>
> I've only had a pot go bad once in over 10 years of owning many of  
> Bob's modules, but a dirty or worn or otherwise slightly duff clock  
> speed pot could be the source of your speed fluctuation rather than  
> anything more complicated. It's easy enough to replace too.
>
> Have you checked that the external clock input socket is clean and  
> the normalising contacts are making good connections when no jack  
> is inserted?
>
> Best of luck
>
> Sean
>
> --- In analogue_systems@yahoogroups.com, coenen olivier  
> <coenen.olivier@...> wrote:
> >
> > Hello Terje,
> >
> > I know a little drift is part of the game with analogue stuff, but,
> > what I've experienced is more
> > than "natural" drift caused by temperature and likes ...
> > I think it is plausible that one or another component is/are beyond
> > suitable tolerance and could/should be replaced
> > for better stability.
> > My problem is to detect the components that might be responsible for
> > the drift...
> >
> > Thanks for your input :-)
> >
> > Cheers,
> >
> > Z.
> >
> > On 16 Oct 2011, at 17:03, Terje Winther wrote:
> >
> > > > I've noticed on several occasions that the clock of my RS-200  
> is far
> > > > from rock steady...
> > > >
> > > Yes, all analogue step sequencers drift a little. Not much, and I
> > > think my AS-200 is fairly steady, but as you have noticed: it  
> is not
> > > rock steady like something digital.
> > > Temperature, humidity and the amount of time used influence the  
> tempo.
> > >
> > > Terje Winther
> > > terje.winther@...
> > > http://www.wintherstormer.no/
> > >
> > > [Non-text portions of this message have been removed]
> > >
> > >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
> 



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