OldSynths

From: Carl Virtanen virtanen@...,
cc:
Subject: Modding the Realistic Moog (mg-1)
Date: Tue, 26 Sep 1995 14:15:55 -0400 (EDT)


Hey there!
Well, thanks to Mark Glinsky for passing along the schematics, i was

able to finally take the plunge and do a mod on the Moog mg-1. I'm
not
sure about the rest of you, but doing that first mod, ie-sticking
your
soldering iron in there and hanging on for dear life, can be a very
nerve
racking experience. Especially when it's that precious little
analogue
jewel you can't afford to screw up on. Anyways, it was a simple mod
so relatively painless. Hence, i'm passing along the info for other
mg-1
owners:

External source filter input mod for the moog-mg1 (realistic)

What you need:
soldering iron
phillips screw driver
knife
solder
0.1 uf capacitor
short length of wire

Carefully remove the case to the mg-1 by unscrewing the screws on
the
bottom and the one in the bottom, middle, back side. This should
allow
you to tilt up the case to expose the bottom of the main circuit
board.
You'll have to take this board out as well by removing the 5 screws
that
secure it in place. Make sure you remember to take the knobs off on
the
front of the synth and be careful with the foam dust covers inside
as
they fall apart easily.

LocATE the level sliders for tone source1 and 2. In between these,
you
should see a polarized capacitor (c14). Locate the (-) negative pole
and
turn the board upside down to expose the solder joint. You'll want
to
connect one end of your wire to this point on the circuit board
using
some solder.

The next step is to connect that wire to the external input. Now,
instead
of drilling a new hole, i used the right aux in from tape. To be
quite
frank, these inputs are kind of ridiculous in the first place, as
they are
only useful if you want to put your stereo through and play
accompanying
music to James Last or perhaps Santa Claus plays the Moog (one of my

faves!). Most people will probably not miss this... ;)

So the next step is to locate the circuit board where these inputs
and
outputs are inside the mg-1. Don't bother removing the board as it's

riveted in. Locate the right aux input on the back of the board
(should
be the one on the far left). You should see where the centre of the
plug
connects and traces up and to the left and the outside of the plug
connecting to the common ground:

\ <--Using the knife, gently scrape away the trace here to sever the

\ connections from the positive centre of the plug to the outputs.
|
|\
| |
0 <--Next, solder one end of the capacitor to the positive (centre)
part of the plug.

Connect the other end of the capacitor to the wire you soldered on
the
main board. The nice part is that the connector is already grounded
so
you don't have to do any more work! Reassemble the beast and connect
a
line level input to the aux in. You should now hear it going through
the
filter! Great for shortwave, didgeridu's, or 808 toms!

Hope this makes sense to everyone. Might be a bit much but i tried
to
write it with the novice in mind.

Good luck, and all the usual disclaimers apply... Ie-proceed at your
own
risk!

Oh, and make sure you unplug it before doing all of this ;)

carl