[sdiy] MS-20 psu conversion from 100V to 240V

[Oscar Salas]

> Hi Andy,
>
> I've converted a few 110V synths for 240V but I can't remember if the
> MS20 was one of them.
>
>  From the circuit it looks like you could just replace the transformer
> if you can find a suitable one, and fit it in there. If your closest
> choice is 18V or 15V secondaries I'd go with the 15V one, as the
> unregulated DC is marked as 18V on the schematic. The power dissipation
> across the regulator may be too high if you use 18V secondaries.
>
> Something like this would be suitable:
> http://www.altronics.com.au/index.asp?area=item&id=M5015
>
>
> If dropout voltage is a problem you could then replace the regulators
> with low dropout types such as the LM2940-15.
>
> Regards,
> Stewart.


Yes you are right, power dissipation must be considered.



> On 5/18/2012 12:44 AM, Andrew Simper wrote:
>> I want to buy an MS-20 rev2, but the only ones I can find all have
>> Japanese 100V power supplies. I have a friends 240V MS20 rev2 here and
>> there is a transformer and fuse mounted on the chassie and then a
>> tripple core wire from the transformer that is soldered directly onto
>> the main PCB. Does anyone know if it is simply a matter of changing
>> that transformer?
>>
>> I'm assuming that the rev2 has the same power supply as the rev1:
>> http://www.korganalogue.net/korgms/images/service/ms20/circ1.gif
>>
>> Cheers,
>>
>> Andy
>> --
>> cytomic - sound music software
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