[sdiy] PT2399 as comb filter experiment

[Scott Stites]

Hi List,

Off and on in the past I've experimented with using PT2399 delay chip as
something other than an echo device.  The main obstacle with using it as a
flanger is that its minimum delay (spec'ed at something like 30 ms) is just
too long to provide a nice smooth flanger like a BBD can.  I think the
PT2399 actually would work fine for a chorus device (I haven't pursued that
much), and it can provide a very lush echo by slightly modulating the delay
time.

Be that as it may, there is a knife-edge of minimum delay range where one
can get some interesting comb filter effects.  I recorded a sample of an
experiment in which I was trying doing just that.  It's tricky to do, and
the results don't have the smoothness nor the sound one would get with a
much shorter delay, but the results are interesting (to me at least).

If you're interested, I've put the sample on my 'Birth of a Synth' page
here:

http://mypeoplepc.com/members/scottnoanh/slsdiy/id18.html

It's the sample linked as "PT2399 Comb Filter Experiment (1.4 MB)" at the
top of the page under "29 October 2004".

Direct link for downloading (long, link) is:

http://mypeoplepc.com/members/scottnoanh/sitebuildercontent/sitebuilderfiles
/2399comb.mp3

Cheers,
Scott