PLAN B analog blog

For the record, different rows is the hopeful solution.  Different
racks (meaning different PSUs) is the best fix.

I had the same problem in my system.  Some modules created noise (LFOs
the worst offenders), some were suspect for interference from that: 
Model 15's and the Frequensteiner which is highly suspect due to it's open amp design. I made it go away by eventually running control modules and audio modules from different PSUs.  That's what fixed it.

hope this helps,

- P




--- In PLAN_B_analog_blog@yahoogroups.com, "deastman2" <deastman2@...>
wrote:
>
> Thanks Peter (and Tony).  I do have an empty rack at the moment, but
> obviously that will get filled eventually, so I was looking for a more
> permanent solution.  The M15 and Dalek are currently in one row, while
> the M28 is in the other row.  The M15, however, is currently the last
> module on the buss board.  I'll try moving it to the center and see if
> that helps.  Thanks again for the suggestions!
> 
> --- In PLAN_B_analog_blog@yahoogroups.com, "(i think you can figure
> that out)" <peter@> wrote:
> >
> > the best solution is powering the M15 if you can from an entirely
> > different rack.  If it's the only one you have, then follow the center
> > most connection suggestion made previously.
> > 
> > There's something that all of the current manufacturers of Eurorack
> > Racks (actually, not sure about Cwejman) have in common:  absolutely
> > no power management.  The manner in which they dasychain the power is
> > about the worst possible way it could be done, for all the reasons
> > you're experiencing.  Modules which by nature (most LFOs, not just
> > Livewire) and anything with a microp in it tend to make noise which is
> > transferred through the ground line.  If there are audio modules
> > powered on the same row, or at worst case from the same supply, all
> > the noise (usually associated wth zero transitions, when something
> > crosses or hits zero volts) picks up that noise.  What is required are
> > separate lines directly from ground to all of the connectors on the
> > row of the bussboard.  A failsafe solution wold be to power contrl
> > modules and audio modules from separate supplies.  This wold fix the
> > proble entirely.
> > 
> > If you scan through the letters on this blog you'll notice this is
> > exactly what we're planning with the Plan B case. There will be one
> > bussbiard to each row, but all grounds will be going directly to the
> > power supply return and every other connector will be physically 
> > offset form one another, one labeled AUDIO and the other CONTROL.  We
> > may actually power each of these from a different set of regulators.
> > 
> > ~m
> >
>