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MF-102 inconsistency?

Posted: Wed Mar 07, 2012 7:15 pm
by PHC
I'm confused. The MF-102 has a Cartier In and Out but the front panel reads Modulator. I was thinking that the Audio In signal is the modulator and the built-in oscillator is the Carrier (but the front panel reads otherwise). Do You think that it's a mistake on the part of Moog Music? I know that since ring modulation is signal multiplication (and multiplication is commutative, a x b = b x a) so the order doesn't matter, but it seems an inconsistency by Moog. Am I mistaken?

Re: MF-102 inconsistency?

Posted: Wed Mar 07, 2012 7:23 pm
by Voltor07
I was under the impresson that the combination of the mix knob and oscillator made the modulator. :?

Re: MF-102 inconsistency?

Posted: Wed Mar 07, 2012 7:30 pm
by PHC
Still not very consistent with Ring Modulation theory? So the oscillator is the carrier and the audio in is the modulator and the front panel modulator sign refers to RM as a whole?

Re: MF-102 inconsistency?

Posted: Wed Mar 07, 2012 9:03 pm
by Voltor07
PHC wrote:Still not very consistent with Ring Modulation theory? So the oscillator is the carrier and the audio in is the modulator and the front panel modulator sign refers to RM as a whole?
I'm guessing that's the case...according to the manual, the carrier oscillator is just that. The oscillator. So plugging something into the carrier input only messes with the oscillator, not the other components. Likewise, the Carrier out is only the output of the oscillator, not the RM as a whole.

Re: MF-102 inconsistency?

Posted: Wed Mar 07, 2012 10:25 pm
by c7sus
Ring mod is sum and difference not multiplication.

http://www.moogmusic.com/forum/viewtopi ... =3&t=12899

Re: MF-102 inconsistency?

Posted: Thu Mar 08, 2012 3:42 am
by PHC
Pluging something into Carrier Input bypasses the built in oscillator and uses the thing You plug in as the carrier. I think that the rear sockets should be labeled as they are, but the front should be labeled Carrier in place of Modulator. I'm making a tutorial about the Ringmod and it's confusing as I'm talking about carrier oscilator and turning the knob under "modulator" label.

Re: MF-102 inconsistency?

Posted: Thu Mar 08, 2012 4:01 am
by PHC
@c7sus: I believe kind Sir You are mistaken ;-) Ring Modulation is a process od signal multiplication (and that is commutative, so technically switching carrier and modulator produce the same effect). The "sums and differences" You are writing about are the frequencies that are products od ring modulation, thr process of RM itself is however signal multiplication. Read the maths if You like:

http://www.media.aau.dk/~sts/ad/modulation.html

Re: MF-102 inconsistency?

Posted: Thu Mar 08, 2012 11:46 am
by DeFrag
Nice link PHC.

I was in the c7sus camp believing Ring Modulation was the sum & difference outputs between two signals.

http://en.wikipedia.org/wiki/Ring_modulation states "Multiplication in the time domain is the same as convolution in the frequency domain, so the output waveform contains the sum and difference of the input frequencies."

Help me understand how multiplication results in sum & differences with regards to amplitude & frequencies.

Re: MF-102 inconsistency?

Posted: Thu Mar 08, 2012 2:41 pm
by PHC
It's all there in that link.

Study the trygonometry equations and you'll see that multiplication becomes sum and difference.

Re: MF-102 inconsistency?

Posted: Thu Mar 08, 2012 4:05 pm
by PHC
http://www.soundonsound.com/sos/mar00/a ... ecrets.htm

Chew on this...

Read the math behind amplitude modulation. It's very well described. Then scroll down to Ring Modulation and read that RMs are AC-coupled which doesn't allow the carrier and modulator to pass through.

Re: MF-102 inconsistency?

Posted: Fri Mar 09, 2012 12:43 pm
by c7sus

Re: MF-102 inconsistency?

Posted: Wed Aug 08, 2012 11:12 am
by fuzulu
i was confused too , seeing that there is modulator written on the oscillator section , which is in fact the carrier , I was confused because I wanted to be sure that the the carrier out is the oscillator out .

Re: MF-102 inconsistency?

Posted: Sun Sep 08, 2013 9:33 am
by miliksitek
C7sus, thanks for the links,
Michael

Re: MF-102 inconsistency?

Posted: Tue Oct 01, 2013 6:12 pm
by krowamlotkowa
fuzulu wrote:I was confused because I wanted to be sure that the the carrier out is the oscillator out .
That`s right, I was confused too, the same reason.

And - C7sus, thanks for the links and big thanks for share!