[sdiy] Re: Aliasing (or not) on Monowave

[René Schmitz]

Hi Paul and all,

Paul Maddox wrote:
>> Paul - on the monowave, do you have a constant-rate DAC, or are you 
>> varying the DAC rate? If the latter, your aliases will be landing on 
>> top of existing harmonics, so you won't get inharmonics and it won't 
>> sound icky.
> 
> 
> the DAC is in 'free run' mode, so basically the moment a value appears 
> on the 8bit data port, it comes out the analogue side (excluding 
> internal delay), so I'm actually not clocking the DAC at all, but the 
> data being passed to the DAC is running at around 925Khz, which is a 
> constant 'update rate'..

And this is the reason why you don't *hear* the aliases. Of course there 
is aliases, but most of them will fall between fs/2 and the hearing 
range. Those that land in the hearing range are way more down than for a 
48k sample rate.

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159