Re: Another new member

["Hogan, Greg" <GHogan@lexicon.com>]

 ----------
From: Loopers-Delight
To: Loopers-Delight
Subject: Re: Another new member
Date: Sunday, February 09, 1997 5:14PM

In reply to Fish saying:
...
>I originally discovered this technique while playing about with a friend's
>Roland tape delay and a wah-wah pedal but it's quite easy to reproduce 
>with
>the EB16. The basic theory is to take a sound, put it through a slowly
>sweeping band pass filter, delay the signal, and then feed it back to the
>start where it gets filtered, delayed and fed back again.
>
>Now, you're probably thinking this is a bad idea and will result in the
>nasty howl around feedback which we're all familiar with having plugged an
>output into it's own input after one spliff too many in the studio. But
>it's the sweeping band pass filter that's the key here. As the filter only
>lets through a certain range of frequencies and eliminates the others, by
>the time the delayed signal is fed back to the input the filter will have
>shifted frequency sufficiently to prevent the signal building up into that
>nasty howl.

Matthias replied:

Did you try to use a compressor, maybe even in the feed back path?

>Depending on the original sound and by adjusting various parameters you 
>can
>achieve a number of weird and wonderful effects. Play a big chord using
>nice thick pad and pass it through the feedback loop and you get a
>beautiful evolving swirl of sound as the various harmonics are picked out
>and emphasized. Take a techno stab, played in time with the delay and your
>riff takes on a life of it's own. Or a few Rhodes chords add a really
>spacey dimension to a dub track. White noise textures also work well with
>the feedback loop adding a lot of movement to the sound. And of course 
>with
>an electric guitar, which is what I first made the effect for, your 
>average
>solo will take right off into space!

I would really like to hear this.

I just tried to implement on the PCM80 with the M-Band algorithm, but it
failed, because the filters have no Q and the feed back is limited to 100%,
so its just fading filtered, which is nice, but not what you are telling
us.
And I am too lazy to create an analog external feedback :-)

The Resonant Chord algorithm create something similar, right Greg?

To which I reply:  The Resonant Chord algorithm in the PCM80 does foldback 
delay voices through filters in the manner that fish has described.

Best regards,

Greg Hogan
Lexicon Customer Service
Phone 617-280-0372
FAX 617-280-0499
email: ghogan@lexicon.com