[sdiy] wavestation backlight whine hack

[Graham Atkins]

Hi Nicolas,

There was audible "whine" on the output of the classic PPG Wave synth  
from the backlight inverter. When the "Soft" PPG
Wave 2.V was created, it allowed you to mix in an amount of whine for  
authenticity !!.

Graham

On 23 Aug 2010, at 10:05, nicolas wrote:

> Hello
>
> Just in case anyone here is interested I thought I would relay a  
> simple hack just completed ...
>
> I have a Korg Wavestation EX with dead backlight, which had the  
> annoying whine that so many of them have now.  I don't really need  
> the backlight enough to be bothered fixing it properly, but the  
> whine was really annoying.  The whine is from the inverter that  
> powers the backlight.  Disconnecting the dead backlight raises the  
> pitch of the inverter to be less annoying, but doesn't stop it.  I  
> read on the net that one person went so far as to remove the  
> relevant transformer, but that seemed a bit drastic, required  
> getting the board out of the synth and a pain to reverse if I ever  
> wanted to return it to original.
>
> A much simpler fix is to cut the power supply to the inverter.  This  
> can be done without removing the board.  The inverter in the EX is  
> on the power supply PCB in the corner opposite where the mains comes  
> in.  The DC power to the inverter arrives via a wire link that can  
> be cut without having to remove the board from the synth.  Cutting  
> the link fixes the whine and is also easily reversible if you ever  
> want to return the backlight to original.
>
> To open the wavestation flip it over and undo all the screws on the  
> bottom.  There are a lot.  Then slide that bottom panel away from  
> the back panel and lift it off.
>
> To identify the wire link, look for the small transformer in the  
> corner of the power supply PCB opposite where the mains comes in.   
> Just to north of it there are some big electrolytics, to the east  
> the connectors taking power to the synth, to the south a small cap  
> and a small transistor.  And to the west of it a wire link then a  
> couple of resistors, all quite close together.  That wire link  
> between the transformer and the pair of resistors is the one to  
> cut.  Its a bit fiddly to cut because it is so close to the  
> transformer, but easier than removing the board.
>
> Cheers,
> Nicolas
>
>
>
>
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