Doepfer

> I'm going to buy the module, but I do think a simple lowpass filter
(with a
> on/off switch) would make it a whole lot better.
> 
> And it won't cost more than a few dollars.


a simple lowpass filter wouldn't make you happy,
you need something better for that.
usually a switched-capacitor-filter with a steep slope
is used for that task, something with 30db slope or even more. 

 
> That Higpitched noise is in my view very unwanted(me being a 
diplomat) and I
> would have to reserve one of my filters especially for the BBD
> module..........
> 
> BTW could it be filtered with a slew limiter?


no, a slew limiter is not for audio. of course some do work
with audio signals, but the filter slope of a slew limiter
is usually 6 db, which is far too soft for filtering of
a bbd.

best wishes

ingo