Re: Start Point - Click in Loop? EDP DC Offset

[openjam@aol.com]

The Butler did it with a screwdriver in the Archives...

Excellent help Andy...this sound like what I have going on.

todd


On Jan 18, 2012, at 8:29 AM, andy butler wrote:

> so the butler was...er...badgered... and managed to dredge up the  
> answer.
>
> Indeed, this has all the hallmarks of the well known DC offset
> problem.
>
> This except from the LD archives explains the fix,
> it's from Kim Flint.
>
> andy
>
> > anyway, for John, here's how to set the trimpot:
> >
> > *********************************************
> >
> > This requires that you actually open up the unit, and have it  
> > opened with
> > the power on. *Please follow appropriate electrical safety rules!! 
> > *  If you
> > are not careful and you fry yourself, please don't blame me!
> >
> > There's a trimpot on the PCB, near the left side, by the volume  
> > knobs. It's
> > job is to trim a dc offset from a VCA. Sounds like your's is not  
> > set right
> > for some reason, which would cause the thump you hear.
> >
> > To set it you need to run one of the built in diagnostic tests. The  
> > test
> > basically turns the VCA on and off at about 60Hz, so if there is an  
> > offset
> > you can hear the resulting tone in an amplifier. (or see it on a  
> > scope,
> > whichever way you like.)  While that's going, you adjust the  
> > trimmer until
> > the tone/waveform reaches it's mimimum.
> >
> > To get into the trimmer test, Start the unit while holding the  
> > Parameter
> > and Record buttons down. Keep them held while the startup screen  
> > goes by,
> > until the display shows all t's. Then let go. Should say 7F. Press
> > parameter so the "Keys" LED is lit, then press Insert to start the  
> > trimmer
> > test.
> >
> > You should hear a ~60Hz tone in an amp. (turning input volume off,  
> > mix to
> > "loop", and the output volume up helps.) The tone will change in  
> > level as
> > you adjust the trimpot. Adjust to where the tone is at it's lowest  
> > level.
> > (you'll still hear hashy noise sounds, but the 60Hz should become  
> > nearly
> > inaudible.)   After you set the trimmer, pressing parameter again  
> > will stop
> > the test. Then you can turn the echoplex off and power back up  
> > normally.
> >
> > **********************************************
> > kim
>
>
> openjam@aol.com wrote:
> > My EDP (Oberhiem with Loop 3, 5.0) has developed a click at the  
> > start point of each new loop. Sometimes its more audible then others.
> > Any ideas?
> > An obvious suspect would be the start point led - perhaps something  
> > has failed.
> > I tried the archives but could not retrieve any similar symptoms.  
> > Please direct if you know of a case.
> > Thanks
> > Todd Quincy