[PD] Karplus/delay question

[Thurstan]

Hello,

while trying to make a simple Karplus/Strong model I ran into something I
cannot figure out.
I cannot seem to get the delaytime smaller than 1.55 seconds thus the
highest note is about
660 Hz. I can visually get the delaytime smaller in the numberbox but this
had no effect
on the actual delaytime whatsoever.

Does this have to do with the I/O blocksize and if so which value should I
give this?
If not is there another solution to get a smaller delay than 1.55 ms?

I used the [vd~] and [delread~] to generate the simple feedback model. I
also used a
[lop~] but switched this off to measure the highest pitch the delay model
could generate.
For the loss in a filterless model I used [*~].

Grtz Wilf