MOTM

Is it possible to make a few modifications to an MOTM-440 Lowpass Filter to
make it a highpass? Not that I would take a Dremel to my own, but I'm just
wondering if a few changes to the layout and front panel legend might yield
a whole new module. A 24 db/oct highpass filter would be useful.

I had a thought today while shovelling snow that a CCD "bucket brigade"
device is similar with electricity to styrofoam or fiberglass insulation is
with thermal energy. They both have little 'cells' that slow down the
transmission of their respective energy types.

Back to our regularly scheduled program.

If you invert the output and sum it with the uninverted input signal, 
you'll get highpass. You could do it with an external mixer with 
reversible phase on the inputs, or build that in on a daughterboard. 
What would it take, a switch, an opamp, and 3 resistors?

Moe

--- In motm@egroups.com, "Tkacs, Ken" <ken.tkacs@j...> wrote:
> 
> Is it possible to make a few modifications to an MOTM-440 Lowpass 
Filter to
> make it a highpass? Not that I would take a Dremel to my own, but 
I'm just
> wondering if a few changes to the layout and front panel legend 
might yield
> a whole new module. A 24 db/oct highpass filter would be useful.
> 
> I had a thought today while shovelling snow that a CCD "bucket 
brigade"
> device is similar with electricity to styrofoam or fiberglass 
insulation is
> with thermal energy. They both have little 'cells' that slow down 
the

> transmission of their respective energy types.
> 
> Back to our regularly scheduled program.

hopefully Paul can institute this in the MOTM mixer.
Jim

Dave Bradley wrote:

> If you invert the output and sum it with the uninverted input signal,
> you'll get highpass. You could do it with an external mixer with
> reversible phase on the inputs, or build that in on a daughterboard.
> What would it take, a switch, an opamp, and 3 resistors?
>
> Moe
>
> --- In motm@egroups.com, "Tkacs, Ken" <ken.tkacs@j...> wrote:
> >
> > Is it possible to make a few modifications to an MOTM-440 Lowpass
> Filter to
> > make it a highpass? Not that I would take a Dremel to my own, but
> I'm just
> > wondering if a few changes to the layout and front panel legend
> might yield
> > a whole new module. A 24 db/oct highpass filter would be useful.
> >
> > I had a thought today while shovelling snow that a CCD "bucket
> brigade"
> > device is similar with electricity to styrofoam or fiberglass
> insulation is
> > with thermal energy. They both have little 'cells' that slow down
> the
> > transmission of their respective energy types.
> >
> > Back to our regularly scheduled program.
>