[sdiy] Various repairs coming up...

[harrybissell]

I'll just take one piece...

If you have a 60VA transformer, I would not go below 60VA. The higher
efficiency
has allready been discounted in the toroid case...

If you go with the bigger one, watch out that the secondary voltage does
not float too
high for you. I find you need to try one and see...and sometimes you lose
your money.

The Oberheim transformers suck (loudly).  All of mine hum as well. Its
acoustic as you
noted. Let me know and maybe I'll fix mine too :^P

H^) harry

ASSI wrote:

> Hi list,
>
> I've had some time to look after the old analog gear and place it
> properly into a new keyboard rack. It turns out my Matrix-12 did get
> the aftertouch upgrade after all, and it is even somewhat useable.
> However "channel pressure" has to be taken very literally, it takes a
> lot of force to get full response, which is why I originally  thought
> there was no sensor. There are two trimpots labeled T1 and T2 where the
> sensor is connected (right next to the PC900 that does the MIDI) - is
> it possible to adjust the sensitivity there and if yes, how?
>
> The hum in the PSU can be traced to the primary transformer, it hums
> just the same with and without load. It puts out just under 18V~
> unloaded, which would be double the voltage in the Xpander (I only have
> the service manual for the Xander), also it is a full bridge rather
> than half bridge rectifier with middle tap. My plan is to replace the
> IEC receptable with one that has an integrated EMI filter and the
> transformer with a toroidal one - the 50VA type from Conrad would be an
> ideal fit while the 80VA type would need a new hole for the mounting
> screw. The Matrix-12 is rated at 60VA, does anyone have the current
> spec for the secondary voltage (the toroids are more efficient, so
> maybe 50VA should be enough)?
>
> BTW, does anyone have the mounting pattern for the individual voice
> outputs? The next time I come near the Matrix-12 with a soldering iron
> I'll put in the connectors on the voice boards. My original idea was to
> put a connector for a multicore into the back, but the original mod
> from Oberheim had the individual ouputs to the left side.
>
> Last but not least the switches on my EX-800 start to misbehave, which
> is especially annoying and severe with the switch that toggles between
> program and parameters. If anyone knows a suitable replacement, please
> let me know, the only thing I found that looks remotely compatible is
> surprisingly Conrad 707678-33...
>
> Achim.
> --
> +<[Q+ Matrix-12 WAVE#46 microQkb/Omega Andromeda XTk/30 sonic heaven]>+
>
> SD adaptation for Waldorf microQ V2.22R2:
> http://homepages.compuserve.de/Stromeko#WaldorfSDada