200e

I'm for posing more technical questions, but I understand Buchla and 
Associates does not support 2nd hand modules.

I reported before that I have a pair of 259e modules.  One module is 
misbehaving and one is good.  I notice that the black and brown wires 
that connect to noisy and quiet ground are reversed in position on 
the PCB of the module that is misbehaving. 

Sweeping the main frequency knob on the misbehaving module results in 
alot of jitter. The Principal osc is also affected by sweeping the 
knob on "fm in" to full even when nothing is patched in.

Are these issue affected by noisy and quite ground?  Should I reverse 
the connections on the PCB to make them consistent with the module 
that is not experiencing these issues?  Or, is thes jitter problem 
because the pot is wearing out and I should just replace the pot?  
BTW, does anyone know the make and model of the pot and values of the 
pots on the 259e?  The fine tuning pot is the only pot with markings.

Thanks!

Roger.

Hi Roger,
I can't answer the questions about the reversed wires (I think you'll have to call b&a), but I 
might there is a procedure for calibrating the  "fm in" knob on the principal osc.  You can 
expect a small bit of offset from the "fm in" knob but if it seems a like a lot, turn it all of 
the way down and then hold down the Midi/hard/soft sync button.  The light should not 
come on.  Now try the knob.  It should solve the problem.  Again.. it WILL offset a tiny bit.
BTW, are both modules running the same firmware versions?

--tom



--- In 200e@yahoogroups.com, "roger.barret" <roger.barret@...> wrote:

>
> I'm for posing more technical questions, but I understand Buchla and 
> Associates does not support 2nd hand modules.
> 
> I reported before that I have a pair of 259e modules.  One module is 
> misbehaving and one is good.  I notice that the black and brown wires 
> that connect to noisy and quiet ground are reversed in position on 
> the PCB of the module that is misbehaving. 
> 
> Sweeping the main frequency knob on the misbehaving module results in 
> alot of jitter. The Principal osc is also affected by sweeping the 
> knob on "fm in" to full even when nothing is patched in.
> 
> Are these issue affected by noisy and quite ground?  Should I reverse 
> the connections on the PCB to make them consistent with the module 
> that is not experiencing these issues?  Or, is thes jitter problem 
> because the pot is wearing out and I should just replace the pot?  
> BTW, does anyone know the make and model of the pot and values of the 
> pots on the 259e?  The fine tuning pot is the only pot with markings.
> 
> Thanks!
> 
> Roger.
>

WOW!  It worked.  And the jitter is gone.  That's awesome.  I 
appreciate your help.  Also, I appreciate the other responses I 
received.  Thank you all!


--- In 200e@yahoogroups.com, "tmeade1974" <tmeade1974@...> wrote:

> You can expect a small bit of offset from the "fm in" knob but if
> it seems a like a lot, turn it all of the way down and then hold 
> down the Midi/hard/soft sync button.  The light should not come 
> on.  Now try the knob.  It should solve the problem.  Again.. it 
> WILL offset a tiny bit. BTW, are both modules running the same 
> firmware versions?
> 
> --tom