[sdiy] MKS-70 Switch internal transformer from US 117 to UK 240

[random variate]

Thanks again Richard

I have a few bits of kit that use the c9 power socket and have power leads. I may update to the c13/14.

The main issue for me is to ensure there are no component changes required such as mains filter capacitors and the fuse.

Was just concerned that you might have found out something I overlooked.

Looks like I can just resolder the transformer and go... Which would be ideal. Just need to double check the fuse issue though methinks.

Cheers

TC 





On 16 Sep 2010, at 23:39, Richard Atkinson <rga24 at cantab.net> wrote:

> The MKS-70 service manual shows different part numbers for the mains filter boards, and the fuse F1 has different ratings, but C1, C2, L1 and R1 are the same. Other than that the mains power connector is different, having a 3 pin socket for 240V. Have a look on page 33 out of 44.
> 
> Since the fuse for 220V/240V is actually smaller than for 100V/117V, it would still work with the larger fuse.
> 
> 
> On Sep 16 2010, random variate wrote:
> 
>> Hi Richard, appreciate your looking in to this.
>> 
>> Am I right in taking your note to mean that I would need to change the mains input filter board too?
>> 
>> I asked on Gearslutz and heard from one chap that the tech that worked on his mks-70 just resoldered the transformer.
>> 
>> Thoughts?
>> 
>> 
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>> 
>> On 16 Sep 2010, at 22:47, Richard Atkinson <rga24 at cantab.net> wrote:
>> 
>>> I just had a look inside my USA MKS-80. The power supply transformer has two taps, one for 100V (Japan voltage) and another for 117V (USA). It's clearly a 117V/100V device with no alternative wiring for 220V/240V. So there is no possibility of rewiring the USA MKS-80 transformer for 240V operation. It would have to be replaced with another transformer.
>>> The MKS-70 service manual on the other hand seems to indicate that there are 100V, 117V, 220V and 240V taps on the MKS-70 transformer. (page 33 out of 44)
>>> Apart from that, the mains input filters are different between 100/117V, 220V and 240V, and there are different power connectors between 100/117/220V and 240V.
>>> On Sep 15 2010, random variate wrote:
>>>> Thanks Richard
>>>> Indeed it's C9, but I'd like to standardise as I use power distributers with built in conditioners which are all c13/14, so I'd like to standardise. I have C9s but the conditioners do clean things up a bit and of course there's surge protection.
>>>> I confess to being a newb with transformer tech so could you help a bit further with regards to what to look for re: parallel/serial below.
>>>> Once I'm happy with the mks job I'm going to rewire my US polysix too Thanks all for replies, very much appreciated
>>>> Tim
>>>> On 15 Sep 2010, at 14:22, Richard Atkinson <rga24 at cantab.net> wrote:
>>>>> If it's like the MKS-80 and the JX-10 I have here, the MKS-70 will use an IEC C9/C10 connector in both its US and UK incarnations. If you can find a UK C9 lead you should be able to use it with your MKS-70 once you have rewired the transformer. Check the transformer very carefully when you do the rewiring job. Many multi-voltage transformers have two sets of primary coils, which are run in parallel for 110V and in series for 220V/240V. On Sep 15 2010, random variate wrote:
>>>>>> Hi there everyone, newb here I'd like to get rid of my step up transformer wart on my US model MKS-70 and have checked the internal transformer: Currently soldered on 117v point and 0v point There are 220v and 240v winding points The power filter board has a 250v rated glass fuse 1. So, is the switch as simple as de/resoldering from the 117v point to either the 220v point or 240v point 2. Would anyone suggest using the 220 rather than 240v point? 3. I'd also like to swap out the 2 pin US square power socket for a Euro 3 pin IEC 'kettle' socket - there's no grounding though? Should I just leave the grounding or would you suggest a chassis pin? Advance thanks Tim _______________________________________________ Synth-diy mailing list Synth-diy at dropmix.xs4all.nl http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>