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RE: EDP loop mode decay question



Oh God!
Thanks for pointing this out;  I didn't read the question properly, I
just saw 'loop decay' and thought of that problem we had with the
crystals.
I've copied this to LD as you have explained the ideas very well and I
don't mind being made a fool of occasionally; it's good for the soul :)

-----Original Message-----
From: Kim Flint [mailto:kflint@loopers-delight.com]
Sent: 19 November 2001 17:11
To: Andy Ewen
Subject: RE: EDP loop mode decay question


actually Andy, that is normal for delay mode operation. It's like having

overdub on all the time. When overdub is on or you are in delay mode we
do 
a slight attenuation each repetition, without which the loops would
build 
up to where it overloaded. Putting it in "hold" stops it from decaying,
and 
closes the input from audio being added to the delay. We do check
whether 
audio is actually present at the input. If the input signal never
crosses 
the threshold during an entire pass of the loop, we do not attenuate
that 
time. (we call this "autoundo" because it works rather like an undo
being 
made of the attenuation that was made during that pass and later deemed 
unnecessary.)

BTW, I didn't post this to the list. (didn't want to embarrass you. :-)
You 
might want to make a correction though, so people are not confused. 
Otherwise you may find yourself repairing every echoplex in the world...

also, I'm pretty sure when you do have the real problem with the
crystals 
causing attenuation, changing the codec does not really fix it. It might

seem like it fixes it, but it will show up again later because it is
really 
the crystals causing the codec to initialize wrong. I was fooled by that

once, in fact when I fixed Cliff's unit the first time. :-) The second
time 
i changed the crystals and his problem went away.... Cliff's edp was the

unit where I figured out what was really happening there. Basically, the

crystal causes the codec to initialize wrong when it boots up, and the
A/D 
convertor causes noise into the loop on the digital side. This fools the

software trick I described above, so our threshold is always triggered
and 
autoundo never works, and the loop decays. The bad thing is in currently

shipping software this happens even if overdub is off, so it always 
happens. For the next version we changed it so this autoundo happens
anyway 
when overdub is off, so the decay can't happen for such a case.

kim


At 04:24 AM 11/19/2001, you wrote:
>Cliff,
>This is not normal and we carry out a 24 hour feedback test here on
every 
>unit to ensure that the loops do not decay over time. This problem is 
>probably related to the 16MHz crystals in your unit not being quite
close 
>enough tolerance. We have found replacing the CRYSTAL Audio Codec chip 
>will also cure the problem.
>Where are you and how would you like to get this problem fixed?
>Andy @ Trace Elliot.
>-----Original Message-----
>From: Clifford@BienAppraisers [mailto:res0koq3@verizon.net]
>Sent: 09 November 2001 19:06
>To: Loopers Delight
>Subject: EDP loop mode decay question
>
>Hiya-
>
>I started using my EDP in delay mode a bit and it seems even at 100% 
>feedback the loop decays over time- is this normal for delay mode? I 
>wouldn't expect it to be- Thanks-
>
>Cliff
>
>PS- I love midi these days- DR-5>ER-1>Filter 
>Factory>Mo-Fx>M-One>EDP>JamMan>Computer - I'm only just getting started
on 
>this setup but syncopated loops of different lengths comes to mind! :) 
>Never used midi on JM before this week-

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