[sdiy] Modding Matrix 6R PSU?

[ChristianH]

Oh dear, cheater. I think this attitude is heavily objectionable, at
least when shown in public.

Ok, it's true that touching 220V isn't necessarily lethal (yup, I know
what it's like too). But this is only when you have the space and the
opportunity to remove your hand immediately. 
Imagine, you stick your finger into a live PSU inside a casing where you
can't get away that quick - don't be surprised if you had to leave the
workshop in a tin box, if you know what I mean.

I'm not one of those who carefully obey all 3 pages of safety b.s. from
the intro of the average instruction manual, but to say 220V can't do
you harm is pretty risky.

Chris



On Wed, 23 Sep 2009 21:38:07 +0100 cheater cheater <cheater00 at gmail.com>
wrote:

> Don't worry, I got shocked by 220V thrice on different occasions as a
> small kid. One more won't do anything the previous ones couldn't.
> 
> D.
> 
> On Wed, Sep 23, 2009 at 4:49 PM, Tom Wiltshire <tom at electricdruid.net> wrote:
> > I did something similar to a US Korg Polysix once upon time.
> >
> > Here's how I'd go about it:
> >
> > 1) Disconnect the transformer secondary wires from the rest of the power
> > supply so you don't blow anything up.
> > 2) Test it as it stands now so that you know how much AC the AC/DC
> > conversion part of the power supply is expecting. You need a 240/120V
> > adaptor for this. Beg/borrow or steal one from a building site.
> > 3) Have a cup of coffee so you brain is awake enough to deal with mains
> > electricity and/or stand on a rubber bathmat ;)
> > 4) Disconnect everything
> > 5) Have a look at the primary side of the transformer. Usually this consists
> > of a pair of windings of which one is used for 120V and both are used (in
> > series) for 240V. Sometimes there'll be four wires, two each for the two
> > windings, and sometimes there are only three, with one common to both
> > windings.
> > 6) Solder it up with both primary windings in series
> > 7) Reconnect and test the secondary output. With a bit of luck, the lights
> > in your house are still on, and the secondary voltage is the same as it was
> > in step 2.
> > 8) If it is, wire it all back up and bingo!
> >
> > Fur gawd's sake, be careful.
> >
> > T.
> >
> > On 23 Sep 2009, at 09:23, cheater cheater wrote:
> >
> >> Hi guys,
> >> I have recently bought a Matrix6R. It's a 120V version, supposedly.
> >> However, it turns out that the transformer inside it is rated as:
> >>
> >> 100V/230V
> >> 41V    30VA
> >>
> >> ..which looks promising I guess?
> >>
> >> The whole marking on it is:
> >> BANDO EP-55
> >> (307-01257)
> >> BE2-GJM
> >>
> >> 61-12663
> >> 100V/230V
> >> 41V 30VA
> >> and then a line of Japanese :)
> >>
> >> soooo.... anyone got a clue what I'd do to make this thing eat 230V?
> >>
> >> Thanks
> >> D.