[sdiy] Butterworth design

[Csaba Zvekan]

Hi group,

I am gonna have to design a Butterworth 2nd Order Low Pass Filter for  
the Audio Output after a 24-bit Burr&Brown DAC PCM1753.
Now my little software for filter design from Texas Instrument is is  
suggesting a 5.23K resistor. If my cutoff frequency is supposed to be  
24.1 kHz -60dB. Of course I don't have that value handy.
My question is if I'd use a 5K6 1% resistor it filters something like  
22.5 kHz almost 2k off .
Is that very critical to the sound & distortion? Or are these just   
standard values /recommendation that have somewhat of a toleranc.
I mean the frequency is not even audible up in that range. Or am I  
loosing valuable high end frequencies with it.But still, I understand  
it causes some digital noise from the ∆∑-DAC that needs filtering.  
Does it have to be exact the frequency 24.1kHz?

Csaba