[PD] Pre Loading a Delay Line

[derek holzer]

Hi Michael,

Michael Garrett wrote:
> I need to pre fill a delay line, in a Karplus Strong oscillator. That 
> data will then be overwritten during the duration
> 
> Of the ‘note’. Is there a ‘built in mechanism for accomplishing this, or 
> do I need to construct something using a table.
> 
> I need the delay line to be interpolating. I am setting the delay based 
> on the incoming note, and ideally would fill the
> line with the same waveform, time dilated to fit the required length.

Short answer: no, there is no way to "pre fill" the delay that is native 
to the [delwrite~] object.

You're on the right track to use a table, however. You could also go a 
step further and build your own delay line using two tables, which 
transfer back and forth to each other with [tabwrite~], and could be 
preloaded with whatever you need. The [tabread4~] object should read 
your tables with enough interpolation for Karplus Strong synthesis. 
Otherwise, [delwrite~] and [vd~] are normally used for this, and [vd~ ] 
seems to interpolate well enough. You'll have to set a very low 
blocksize with the [block~] object to synthesize high frequencies in any 
case.

In the past, there's been quite a bit of discussion about KS synthesis 
on the list. And it sounds like you have a rather complicated approach 
to it (or at least more so than standard KS synthesis). If you're 
interested, it might be worth checking some of these threads for more tips.

best,
d.


-- 
derek holzer ::: http://www.umatic.nl
---Oblique Strategy # 200:
"How would you explain this to your parents?"