Vintage Synth Repair

They do tend to fail in groups, usually if there is a floating earth potential in the equipment that you connect the K2000 to via the audio jack. It is a bit if a job to get the board out and replace the FET's, most people just clip them off altogether and put up with turn-on thumps.



________________________________
From: soundcrafter <aurastar@...>
To: vintagesynthrepair@yahoogroups.com
Sent: Tuesday, July 28, 2009 2:12:31 PM
Subject: [vintagesynthrepair] Re: Kurzweil K2000 Query

  
Interesting. .. can anyone confirm this?  Or would it be a bad idea?

> If memory serves you can even remove them.  Like an appendix or tonsils.
> 
> GB
> 
>   ----- Original Message ----- 
>   From: soundcrafter 
>   To: vintagesynthrepair@ yahoogroups. com 
>   Sent: Monday, July 27, 2009 7:13 PM
>   Subject: [vintagesynthrepair ] Re: Kurzweil K2000 Query
> 
> 
>     Some others had suggested this as well, so I think I will start my checks here. 
> 
>   There is one of these on each output? If so, it seems unlikely they would both fail at the same time, in the same way. Is there some common control circuitry? If so, what should I be looking for? Voltage, or lack thereof, on one of the legs of the FET?
> 
>   Any help is appreciated, as I'm flying blind without the schematics
> 
>   DTK
> 
>   >
>   > 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.
>   >
>