RE: repeater question

[Kim Flint <kflint@loopers-delight.com>]

At 08:37 AM 8/26/2001, Tom Ritchford wrote:
>what I'd really love is a feedback parameter that goes a
>little OVER 100%.  the reason for this is to "bring loops
>back from the dead," so to speak.  I often find that loops
>get very cool artefacts when I let them fade out and I'd
>love to bring those artefacts to the fore...

On the EDP you can accomplish something like that using the multiple Undo 
feature. You can undo feedback passes, bringing back something that has 
faded away. This isn't quite what you are looking for, because of course 
it 
also undoes any artefacts that have developed. It is a great feature for 
evolving and redirecting loops though. You can reduce the feedback level 
and be adding new bits to the loop as the old bits fade away, so your loop 
is evolving in a particular direction. Then use Undo multiple times to go 
back in time as many layers as you want, so the old parts that had faded 
gradually come back again and the new things you had added disappear. 
Since 
the feedback change has been applied to each layer, Undoing it takes that 
pass of feedback away! Then do the process over again, taking the loop in 
a 
different direction. You can imagine it as dipping in and out of some new 
textures, or as a way to go on little excursions with your loop and then 
smoothly return to your original theme, and be able to do it over and over 
again, producing new variations and returning to your basic theme.

The echoplex does it's feedback digitally anyway, so there are a lot less 
artefacts developed as the loop fades away than in older delays. (I guess 
that is what you are referring to.)  In the older delays the feedback path 
would be done in analog, even when the delay line was digital. Every pass 
went through the AD/DA convertors, and through some analog gain circuits 
for the feedback. So you would pick up a lot of noise and junk with each 
successive pass. That's probably interesting if sound textures are what 
you 
do, but really annoying if rely on loops to be a more perfect recreation 
of 
what you put into them.

The >100% feedback is an interesting idea. the practical problem with that 
in a looper is that you frequently want to set your loop to exactly 100% 
feedback, and quickly slide in and out of that point. That is a bit 
different from how people usually work with delays, where most of the time 
feedback is reduced and you hardly ever set it to 100%. So in a looping 
context, knowing exactly which point of the control equals 100% is 
critical. It is very handy to know you can just spin the knob all the way 
clockwise without even looking at it, and you are there. If you could only 
get 100% by going almost but not quite all the way clockwise, or you had 
to 
line up with some mark on the front panel, or land correctly in a detent, 
you would miss it frequently when you are trying to work fast. A lot of 
people would get frustrated with that! On the echoplex we even designed it 
so that 0% and 100% occupied a greater portion of the range, so even if 
you 
slightly missed with the knob you could still get what you want. (this 
also 
compensates for tolerances in the hardware, another major problem if the 
user has to line the knob up to a certain point....)

kim


______________________________________________________________________
Kim Flint                     | Looper's Delight
kflint@loopers-delight.com    | http://www.loopers-delight.com