EDP feedback (was Re: repeater question)

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

At 05:49 AM 8/26/2001, Doug Cox wrote:
>I have an EDP.  It may be a bit misleading to say that the feedback (or as
>the first msg put it, "fade level") is only applicable when the track is
>being recorded.  If I start a loop and then take the EDP out of
>recording/overdub mode (all lights green), the feedback control still
>applies to that loop.
>
>Maybe I misunderstood what you said?  Just wanted to make sure that the
>poster had a good understanding of the EDP's capabilities.

There are two ways you can have feedback control in the Echoplex. The 
default way is what we call "Loop" mode. In this mode, feedback is 
independent, so it is always available as a way to alter the loop, whether 
you are overdubbing or not. To me, this is one of the really important 
innovations that Matthias made in the basic Echoplex design, separating 
his 
original Loop/Delay (and then the Echoplex) away from the way delays 
worked 
and making feedback into a much more important control over the loops. 
With 
it always continuously available, you have a lot more flexibility over its 
use. For example, while a loop is steadily fading out, you can be 
otherwise 
playing material *without* overdubbing something new (and not otherwise 
needing complicated mixer setups to do this). Then, independent of the 
feedback effect on your loop, you can choose when and what you want to be 
adding in to the loop by turning overdub on and off. Or for that matter, 
you could be using other functions like replace or whatever, independent 
of 
feedback. Eliminating this somewhat arbitrary connection between 
overdubbing and feedback gives the Echoplex an interesting degree of 
flexibility that turns out to be really useful in a live looping context.

The echoplex also has "Delay" mode, which makes it follow the old style of 
feedback operation that delays always had. In that mode, the loop input is 
normally open as it is in a delay, and feedback is active only while audio 
is being added. (in fact, the delay input is immediately open in this case 
after you set the length with the Record, just as it would be in a delay.) 
In Delay mode, the Overdub button actually becomes the "hold" function 
normally found in delays. When you press Hold, the input to the delay is 
closed so no more audio goes in, and the feedback is set to 100% so it 
repeats infinitely. Changing the feedback knob doesn't have any effect 
while Hold is on. As soon as hold is turned off, feedback is active again. 
That option was kept because so many people into looping were coming from 
the long delay approach, and wanted to continue working in the same way. 
So 
fine, we give them that. Then the people ready to move on to the next 
step, 
or those new to the whole concept, can go on to the new way of thinking in 
Loop mode.

In either case, you also have continuous, live control over the feedback, 
just as it always was with delays. So at any time you can change the 
feedback knob at the rate you want and hear that sweep in the next 
repetition of the loop. If you want, you can pick some section of your 
loop 
to fade out, and another section to preserve. Each time you get to that 
section you turn the feedback down some and as you get past it you bring 
it 
back up again. You could use this to steadily evolve only one part as the 
rest remains static, for example.

This is different from some other devices that just have a small number of 
discrete feedback levels that effect the entire loop. (like the jamman). 
You can't really change those in a live way, you just set it and it takes 
effect at the next loop repetition and the whole loop is changed. So you 
can't really get smooth feedback level changes, it always goes into it 
suddenly. You can't smoothly change from one feedback level to another, 
you 
just jump to the next discrete level. And you can't pick a section of your 
loop to fade out while the rest stays unchanged. If you want that sudden 
change effect, you can still do it in the Echoplex, you just have to do it 
with MIDI. Feedback level can be set at any time with continuous 
controllers. So you can set it to a discrete level or sweep it around with 
a midi controller or whatever.

kim



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