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Re: Is my filter faulty (A101-1 Vactrol)?

2009-07-30 by mickgrit

--- In Doepfer_a100@yahoogroups.com, <yahoo@...> wrote:
>
> > Thanks for the help Dieter.
> >
> > I have noticed that the problem only happens when connecting the
> > A101-1 to the modules on the MIDDLE row of my 9u cabinet. I have
> > removed all the modules from the middle row and tried them
> > individually and the problem still occurs.
> >
> > The excessive noise from the filter happens if I connect the
> > filter to ANY point on the middle row.  It does not happen on the
> > top or bottom rows.
> >
> > I am concerned that it may be the power supply or would you still
> > suggest that the filter is faulty.
> >
> > Many thanks
> >
> > Carter
> 
> What kind of 9U cabinet is used ? If there's only one power supply in the
> cabinet it should make no difference. Double check if one of the supply
> connections (between PSU und bus boards) is loose or broken.
> 
> Is the noise like a white noise (e.g. like the A-118) or hum noise with
> 50/60Hz ?
> 
> Best wishes
> Dieter Doepfer
>

It is the LC9 case. I have checked for loose connections but I will have another look.  The noise is like if you turn the gain up full on a mxing desk with no input - just amplified circuit noise/interference. Certainly not pure white noise.

I do not think there is any mains hum but I will check tonight.

Cheers

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