I just performed the FM-800 MOD yesterday and while it appears to work
fine, (all three knobs change the sound) it appears that the FM knob
controls the cutoff as well. I believe Tim was the person who had this
same problem. I looked through all the posts, but couldn't find a
reference to the correct / "right" way to wire this.
When I had just the moog-slayer mod on the keyboard, I could have use
of the full cutoff range. Now the cutoff is similar to the resonance
pot, where you have to manually enter a number (say '12') and then
turn the knob so you can hear the effect. In other words, the cutoff
no longer goes all the way off after adding the FM-800 mod
I performed the exact instructions from Atom's FM-800 page. I used a
5k linear taper pot, and soldered directly to the resistors, instead
of replacing them.
Here is part of the information that I found. I believe if you search
for message # 1525 you will find more about it.
On Thu, 13 Apr 2006, Tim Bieniosek wrote:
> So! The interesting results from last night's experimenting is... I
> like my "mistake" better :)
>
> It sounds like you get less of the filter cutoff range if you do it the
> "right" way. I couldn't get the filter to do the whole subsonic -
> infrasonic sweep that I showed off in my demos, or the vowel sounds.
>
> So as soon as I was done testing the intended mod, I put mine back to
> the wrong way :) The sounds are just cooler. I'd invite others to try
> it out and see what they like. (There is also a photo up of the "right
> way" now.)
=======================
i ∗think∗ what's happening is that as you turn the FM knob, it's also
affecting the cutoff. you could (according to this theory) achieve the
same thing by wiring it the "right" way and turning the FM and cutoff knob
together.
you could also turn the knobs in opposite directions, or independently, or
at different rates... in other words, you can do the same thing, and more.
the "mistake" would sound more dynamic because it's doing more than one
thing at a time; adjusting the FM and the cutoff.
if it sounds good, do it. but if you get a chance to test out my theory,
let us know how it goes.
If anyone has any suggestions it would be much appreciated!
And Atom, lunch is on me next time you're in Pleasanton, CA
Thanks,
Steve