MOTM

It has been brought to my attention I have a "wrong" instruction in the manual. (DON'T PANIC,
KEEP READING).

On the top of page 11, you are told to add "input grounding" leads on the 3 IN jacks.
Errr....NOPE!

In fact, if you look at the schematic, these connections are *not shown* (the schematic IS
correct, my instructions are not).

So, unrack, the modules, remove the power cable, and carefully remove these connections with a
pair of dikes (diagonal cutters for the newbies, stop with the wisecracks already). If you bought
*assembled* modules, these may be 'missing' already. When present, there is a silver wire
soldered from the TOP lug to the BEVELED lug. Be careful that clipping the leads go not cause
them to fly off into the other modules :(

You DO NOT HAVE TO DO THIS if you don't want to. I *am* changing the manual for future shipments.

Why do this? Because in the '490, the input summer is NOT like all the other VCFs, and these
added connections to ground (when no signal is patched in) will GREATLY REDUCE the overall signal
through and out of the filter. Be prepared, the difference is pretty dramatic :)

Again...this ONLY IS FOR THE '490. LEAVE YOUR OTHER FILTERS ALONE!!

Sorry about that, this is what happens with too much "cut and paste" going on.

OK, back to soldering..........

Paul S.

On Tuesday 25 November 2003 00:18, Paul Schreiber wrote:
> Why do this? Because in the '490, the input summer is NOT
> like all the other VCFs, and these added connections to
> ground (when no signal is patched in) will GREATLY REDUCE
> the overall signal through and out of the filter. Be
> prepared, the difference is pretty dramatic :)

I just patched my 490 and got an extra 6 dB of gain, and now 
is at unity gain (or near) when fully open. :-)

Btw, the 440 is still louder, as it can boost the input 
signal when the corresponding mixer knob is fully open.

- Robert

> I just patched my 490 and got an extra 6 dB of gain, and now
> is at unity gain (or near) when fully open. :-)
>
> Btw, the 440 is still louder, as it can boost the input
> signal when the corresponding mixer knob is fully open.
>

Both correct observations (note: the '490 won't *seem* louder if a VCA is used, patch the output
directly to hear the difference).

The Moog ladder is a "low signal" device. The original 904A modular VCF ran at only 2V pk-pk!

Paul S.