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Intermittent OBXa filter issue

2011-09-19 by Tim P

Hi all,

I was wondering if anyone has had this issue before and knew how to troubleshoot it.

Sometimes when I turn my OBXa on, half the voice cards (four, all on the same upper board) have an issue where the filter isn't bright enough or sounds like it is not opening up enough for the way the patches are supposed to sound. The cards on the lower tray sound fine.

This problem will crop up, last for a day or so and will go away for a while. Sometimes repeatedly turning the machine off and on a few times will clear it up.

I swapped the 3360 on the board in question and that didn't fix it. Anything else it could be on that upper board? Anyone else have the same problem?

Thanks,

Tim

Re: [oberheim] Intermittent OBXa filter issue

2011-09-19 by Nick Zampiello

it is strange that its one whole board.

maybe re seat the connectors and see if it stays right for a while.  how are the data dacs set up on that machine? could it be that each board shares some of those global settings? 


i know that my ob8 does card/memory/recall stuff like that sometimes and i usually can to go through the split dual menus and then re tune the voices to get it to behave properly.

like the brains need to get jostled!

they are moody machines!

;-P

 
z




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________________________________

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From: Tim P <timpriv@...>
To: "oberheim@yahoogroups.com" <oberheim@yahoogroups.com>
Sent: Sunday, September 18, 2011 8:19 PM
Subject: [oberheim] Intermittent OBXa filter issue

Hi all,

I was wondering if anyone has had this issue before and knew how to troubleshoot it.

Sometimes when I turn my OBXa on, half the voice cards (four, all on the same upper board) have an issue where the filter isn't bright enough or sounds like it is not opening up enough for the way the patches are supposed to sound.  The cards on the lower tray sound fine.

This problem will crop up, last for a day or so and will go away for a while.  Sometimes repeatedly turning the machine off and on a few times will clear it up.

I swapped the 3360 on the board in question and that didn't fix it.  Anything else it could be on that upper board?  Anyone else have the same problem?

Thanks,

Tim

Re: [oberheim] Intermittent OBXa filter issue

2011-09-19 by 65 Lotus

On the upper control board to the left of the voice cards, pull all of the following TL084 chips that are socketed, carefully clean the pins with a pencil eraser and reinstall. I like to use the big artgum erasers you get at a craft store or artists supply store, but if you have a nice, new pencil with a soft eraser, that will work too.

On the upper right quadrant:

137

138

139

140

Middle right:

146

147

That should do it. If not, let me know.

Scott in Ohio

Re: [oberheim] Intermittent OBXa filter issue

2011-09-19 by Tim P

Thanks.  I will try pulling/cleaning the chips first (sounds like an easy fix).  If not, I will replace the caps, like James suggested.
 
I appreciate it.
 
Tim

Show quoted textHide quoted text

From: 65 Lotus <Lotus@...>
To: oberheim@yahoogroups.com
Sent: Monday, September 19, 2011 5:57 AM
Subject: Re: [oberheim] Intermittent OBXa filter issue

On the upper control board to the left of the voice cards, pull all of the following TL084 chips that are socketed, carefully clean the pins with a pencil eraser and reinstall. I like to use the big artgum erasers you get at a craft store or artists supply store, but if you have a nice, new pencil with a soft eraser, that will work too. 

On the upper right quadrant:

137
138
139
140

Middle right:

146
147

That should do it. If not, let me know.

Scott in Ohio

OBERHEIM SYNTH

Intermittent OBXa filter issue

Intermittent OBXa filter issue

Re: [oberheim] Intermittent OBXa filter issue

Re: [oberheim] Intermittent OBXa filter issue

Re: [oberheim] Intermittent OBXa filter issue

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