ODP: DCO's, Anti-Aliasing, and Filters

[Roman Sowa]

Post filtering has nothing to do with aliasing originated at phase
accumulator
waveforms. You can only filter DAC result which is already "infected".
Since you have sigma-delta DACs with filters onboard, there's no need for
additional filters.

Aliasing comes from reading sample faster than it was recorded
(i.e. for playing it at higher pitch)

But hey! those are not so bad filters for other purposes.
At this price...

Roman

> -----Oryginalna wiadomość-----
> Od:	inman at interpath.com [SMTP:inman at interpath.com]
> Wysłano:	1 grudnia 1998 06:07
> Do:	synth-diy at mailhost.bpa.nl
> Temat:	DCO's, Anti-Aliasing, and Filters
> 
> I just read in Nuts and Volts about MAXIM's new filters:  5TH-ORDER 
> FILTER ("5th-order lowpass, switched-capacitor Butterworth and Bessel 
> filters available in 8-pin mMAX and DIP packages," MAXIM web page)
> 
> The best part:  8TH ORDER FILTER $2.00 US.
> 
> Although ads can be very misleading sometimes, it sure does sound as if
> this little chip would reduce a tremendous amount of undesired alias
> waveforms caused by imprecise timing of the period of square waves or
> A/D coversion of phase accumulator waveforms.  At a decent price.
> 
>