[sdiy] Audio Anti Aliasing Filter

[Tom Wiltshire]

Hi Scott,

On 20 Dec 2012, at 15:08, Scott Gravenhorst wrote:

> 
> What are people here using for audio anti-aliasing filters?  
> 
> I'm looking for something simple.  In my own mind, I'm thinking state
> variable lowpass with unity Q and cutoff of some 20 kHz for sample rates of
> 44.1 kHz and above.  
> 
> Are there better or simpler?

There are definitely "simpler" than the state variable. Why choose that if you don't need the non-lowpass outputs?
I use the Analog Devices filter tool for jobs like this:

http://designtools.analog.com/dt/filter/filterW.html

Sallen-Key or MFB would save you a couple of op-amps over SVF. After making that choice, it's mostly down to finding a convenient set of components.

HTH,
Tom