[PD] Zero delay feedback, with settable send?

Frank Barknecht fbar at footils.org
Sat May 12 09:22:26 CEST 2007

Kim Taylor hat gesagt: // Kim Taylor wrote:

> Actually, sorry- I thought I understood this but I've got a problem
> with this method
> Considering the patch posted by Georg Holzmann (the same principle as
> http://crca.ucsd.edu/~msp/techniques/latest/book-html/node121.html)-
> Surely if the block size is default 64 samples, the delwrite atom will
> take at least 64 samples to write to the delay line... 

Not quite: The blocksize just specifies, how many samples [delwrite~]
will write into the delay line during every block. The time it takes
logically is zero: The full block is written into the delay line
immediatly (that is: at the same time, delread~ reads it, see below). 

> So the delread (next in sequence) cannot read out the contents of
> the delay line until AFTER this has happened?

Yes, if you do the execution order right, the delread reads the delay
buffer, after delwrite~ has written into it. That's the whole point of
the order forcing! But as with the delwrite~, the reading happens
"immediatly": delread~ will read a full block from the delay line,
which means, it will read out exactly what delwrite~ has written into
the buffer previously. As both writing and reading happens in the same
sample block, you have no delay. In theory, that is.

> I don't understand how a minimum delay of 1 sample can be achieved
> (although I admit I have made it work in practice!!!)

Actually I think, theoretically a minimum delay of zero samples could
be achieved (although I admit I have not made it work in practice!!!)

More thought needed here ...

 Frank Barknecht                 _ ______footils.org_ __goto10.org__

More information about the Pd-list mailing list