JX-8P X-Modulation - Please Explain!!!
Radical Inc.
be darned if I can figure this out. My guess was that the output of one
oscillator modulated the frequency of the other. But it doesn't sound like
it.
Here is what the manual says about the various XMOD settings:
"SNC 1: The pitch is determined by DCO-1, and the harmonic content by DCO-2.
The waveform is determined by the DCO-2's syncronization to DCO-1."
Sounds like DCO-2 modulates the frequency of DCO-1, no? And what is that
second sentence supposed to mean?
"X MOD: DCO-1 and DCO-2 affect each other, pitch, harmonic contents, and
waveform."
Sounds like the two oscillators modulate each others' pitches. Hmmm. Maybe
my FM background is getting in the way.
"SNC 2: Both SYNC 1 and XMOD work together."
But, ... but, ... if the XMOD setting causes the two DCO's to modulate each
other, does this make sense? They modulate each other AND DCO-1 modulates
DCO-2?
This is making me feel awefully stupid. I hope this isn't some silly
feature that doesn't do anything. If it's anything like the PolyMod section
of the Prophet-5, then it should be a pretty potent feature.
*sigh*
Anybody?
Graham Collins
In a previous posting, Radical Inc. (rad...@infomatch.com) writes:
> Does anybody know exactly what the Cross Modulation does on the JX-8P? I'll
> be darned if I can figure this out. My guess was that the output of one
> oscillator modulated the frequency of the other. But it doesn't sound like
> it.
>
> Here is what the manual says about the various XMOD settings:
>
> "SNC 1: The pitch is determined by DCO-1, and the harmonic content by DCO-2.
> The waveform is determined by the DCO-2's syncronization to DCO-1."
>
> Sounds like DCO-2 modulates the frequency of DCO-1, no? And what is that
> second sentence supposed to mean?
>
> "X MOD: DCO-1 and DCO-2 affect each other, pitch, harmonic contents, and
> waveform."
>
> Sounds like the two oscillators modulate each others' pitches. Hmmm. Maybe
> my FM background is getting in the way.
>
> "SNC 2: Both SYNC 1 and XMOD work together."
>
> But, ... but, ... if the XMOD setting causes the two DCO's to modulate each
> other, does this make sense? They modulate each other AND DCO-1 modulates
> DCO-2?
The cross-mod function is in fact not FM synthesis, but AM
synthesis...i.e. Amplitude Modulation.
Graham Collins
Kent Williams
not only doesn't sound metallic, doesn't sound like Ring Mod, which is
the other thing they call it. Does anyone really know what's going
on?
I'm about ready to start sampling it into the computer to try
and figure it out.
--
Kent Williams -- ke...@cadsi.com | Opinions expressed here are those of |
"A man who has nothing in | a two headed peg-legged midget who |
particular to recommend him | lives in my ear, not CADSI's |
discusses all sorts of subjects at+--------------------------------------+
random as though he knew everything."-One of Sei Shonagon's Hateful Things
J.J. Bruintjes
>Here is what the manual says about the various XMOD settings:
>"SNC 1: The pitch is determined by DCO-1, and the harmonic content by DCO-2.
>The waveform is determined by the DCO-2's syncronization to DCO-1."
This is standard oscillator sync I guesss; DCO2 is synchronized to DCO1
whioch means that DCO2 is resetted at every new waveform cycle ofd DCO1;
if DCO1 is a C4 for example than DCO2 will also be a C4; but its pitch
setting has a nice and peculiar effect on the way DCO2 sounds.
>"X MOD: DCO-1 and DCO-2 affect each other, pitch, harmonic contents, and>
waveform."
>Sounds like the two oscillators modulate each others' pitches. Hmmm. Maybe
>my FM background is getting in the way.
Sounds like FM to me too. I can't figure out what else it should be. It
should therefore have an obvious effect when you turn this feature on and
fiddle around with the pitches of both DCO's. It seams to me that here one
DCO is modulating the other.
>"SNC 2: Both SYNC 1 and XMOD work together."
>But, ... but, ... if the XMOD setting causes the two DCO's to modulate each
>other, does this make sense? They modulate each other AND DCO-1 modulates
>DCO-2?
Well; this makes both sync and FM switched on I guess.
>This is making me feel awefully stupid. I hope this isn't some silly
>feature that doesn't do anything. If it's anything like the PolyMod section
>of the Prophet-5, then it should be a pretty potent feature.
>*sigh*
>Anybody?
Well I hope I gave you a useful hint. It ought to be a powerfull feature as
you already guessed.
B.
Fabrizio Lunghi
i'm not sure but here's what i think....
SNC 1. this is the classic osc-sync system often employed on old
analogue mono's of yesteryear.it basically works like this...
imagine DCO-1 set-up with a square waveform and DCO-2 with a sawtooth
waveform.everytime the DCO-1 waveform begins a new cycle
(ie goes from low to high see fig below) it resets the cycle of
DCO-2's waveform.so if for instance DCO-1 is tuned slightly higher
than DCO-2 then you can see that the wave cycle of DCO-2 would be
continually reset prematurely giving the new more complex shape
(and hence a different tone) for DCO-2 as shown below.
You can further add tonal movement by pitch bending DCO-2 only
typically by using an pitch envelope and fixing DCO-1.This will give
you a classic wow/lead synth scream or growl depending on how you set
up the envelope.check out any Ultravox or John Foxx album for an
example of this unique and powerful sound.
_____ _____ _____ ____
| | | | | | |
DCO-1 | | | | | | |
____| |_____| |_____| |_____|
\ \ \ \ \ \
| \ | \ | \ | \ | \ | \
DCO-2 | \ | \ | \ | \ | \ | \
| \| \| \| \| \| \
\ \ \ \ \ \
DC0-2 | \ | \ | \ | \ | \ | \ |
with | \ | \| \ | \| \ | \|
sync | \| \| \|
X-MOD however is probably ring-modulation where the frequency of both
DCO's is added and Subtracted then those frequencies mixed for the
final output.Again this feature was found on many old synths and was
used to create clangorous/bell like tones.
for example imagine DCO-1 is set at 440Hz and DCO-2 set at 500Hz then
the output would be a mix of 440 & 500 & 60 & 940hz.its a lot more
complicated than this since all the harmonics in a typical waveform are
similarly processed to give many musically unrelated harmonics which
give rise to the clangorous tones.
unfortunately i can't draw this so i'll leave it to your imagination as
to what the output would look like
SNC-2 is simply a mix of osc-sync & ring-modulation.
Good look and let me know how you get on!!! fAb.Uk
Fabrizio Lunghi