Vintage Synth Repair

From memory I think that it is normal for one output to be louder than the other if you only insert one plug, as there is a switching jack to sum one of the outputs to mono of both channels, so don't try and test by putting a jack in one side at a time, check by connecting BOTH outputs to a mixer and see if the level is the same between both channels, if so then the machine is fine. 



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From: soundcrafter <aurastar@...>
To: vintagesynthrepair@yahoogroups.com
Sent: Sunday, August 2, 2009 2:37:00 PM
Subject: [vintagesynthrepair] Re: Kurzweil K2000 Query

  
Alright, I got a chance to try this out, and it seems to have made things better, but I'm not sure its completely fixed just yet.

I clipped the FETs located behind the L and R jacks.  The output definitely got louder from both jacks, and the headphone jack, but it seems (and I've now confirmed with my mixer) that the L output is considerably quieter than R.  I *may* have heard a bit of crackling there also, I'm not sure... I have to play a bit more and see.

Anyway, it seems like progress, which is good! Thanks for the assistance.. . Any suggestions going forward?

Thanks

> It is not uncommon for failures of the J109 FET's on each output of the K2000 to fail. They are there to prevent turn-on thumps through your speakers.
> You can also put the synth into diagnostic mode and run the relevant tests. Or, you can save your patches to floppy and hard reset the machine as a first step in case it is a software issue.
> 
> 
> ____________ _________ _________ __
> From: soundcrafter <aurastar@.. .>
> To: vintagesynthrepair@ yahoogroups. com
> Sent: Tuesday, July 14, 2009 9:16:43 AM
> Subject: [vintagesynthrepair ] Kurzweil K2000 Query
> 
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> I'm taking a look at a K2000 for a friend. 
> 
> We were playing, and suddenly the K2000 lost volume...  It wasn't a dramatic loss, the patch was still audible, but there was *definitely* a loss in volume.  The patch wasn't changed or edited, mixer settings weren't changed, etc.  It just got quieter all of a sudden.
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