[sdiy] Experiment with bandlimited ramps

[Scott Gravenhorst]

Tom Wiltshire <tom at electricdruid.net> wrote:

[...]

>I did a similar recording. In my case, I recorded a single ramp wave  
>from my Pro-One (pair of CEM3340 ramps) and compared it with a pair  
>of bandlimited ramps from my dsPIC DWGS oscillator (which only has 64  
>harmonics incidentally).
>Have a listen to that and see what you think:
>
>http://www.electricdruid.com/ProOneShort.aiff
>
>http://www.electricdruid.com/ProtowaveShort.aiff
>
>There's some difference in the beat frequency between the two sets of  
>oscillators, but in terms of actual sound quality, I was pleased with  
>the digital version. Perhaps the fact there are two oscillators hides  
>the digital sterility?! ;)
>To be honest, I got all "engineer" about it, and decided that "good  
>enough" probably is just that, even if there is some tiny/subtle/ 
>measurable difference.
>

I don't mean to yank this off it's topic, but I've done similar things - and I think
that there is a "hiding" effect when using more than one signal source.  I've found
other ways of enhancing and otherwise sterile digital signal to "naturalize" it. 
One very effective method is to use very low frequency noise (at very low amplitude)
to modulate the pitch of the two signals involved, this causes the beat repeat rate
to stay within a range, but be unpredictable.

I agree that good enough is good enough.  And that sound quality is in the ear of
the behearer (ahem).

-- ScottG
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-- Scott Gravenhorst
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