synchronizing osscilators

[jee_pack]

I guess, right now I'm at work, I'll do as soon as I guess a chance, I just realised (5 minutes ago) that you could put pictures in your topics, although I seem to have got a tiny thumbnail... is there another link I can use to show you the full size picture with this forums free picture web host?

[jee_pack]

ok so here's my theory, okay, it could be way off, but maybe that's how the patch works (I will post a screen shot later cause right now I'm not at home). One thing I remember from the patch is that it used the 2 oss mixed together with almost a 50/50 balance, and I also remember that one of the 2 (the 2nd one) used the (-) sign combined with the phase offset which in theory, create PWM.

So here my theory, to "immitate" an oss that is synced by another. Take a normal oss, imagine what it would look like if it had a longer cycle that was actually reset before it would ever reach the end of the cycle... So I pictured that in my mind, and replicated it by taking a normal ass and adding signal from another oscilator on top of it. Having the combined signals look like an oss that is being synced by another...

So to demonstrate this, look at this picture:
http://img239.imageshack.us/img239/4622/theoryur4.gif

-On the left side of this picture, you can see oss X which is just a normal square wave that goes through its entire cycle before starting over.
-Underneath that (a), you see that same oss completing 2 cycles in the same amount of time (which I guess is done by have X be one octabe lower than A... but I could be wrong).
-Under that (B,C,D), you see what "A" looks like if you use the (-) sign and the phase offset knob to control the width of the pulse (in this way you can make the pulse width to be anywhere from "0" or "silence" to "the full size" like in A). B,C,D are all different variations of the phase offset knob which result in different Pulse Width.

Next to that, on the right, you see what the total ouptput signal of the synthetiser would look like if you mixed the signal from both oscilators together; always using X as the 1st oscilator and any of the others in the picture as the second oscilator...

To me, that's pretty complicated and of course, it does not behave or sound exactly like OSS SYNC, it has limits, it can't have the square wave cycle be reset before is at least goes through a small portion of the silence that the cycle contains (minus infinity, or 0). And also, there is no ossilator syncing anything, so I guess it would be even more complicated to emulate a modulation (like using an eveloppe to modulate the pitch of the syncing oss)... But anyways... I guess you gota work with what you have... and maybe this is the only way to sync oscilators in reason...

I will post a screenshot of the patch later, maybe you'll figure it out and help me understand this... And please let me know if my theory is way off or if it doesn't "Sync oscilators" in anyway... Thanks in advance

[LBN]

[jee_pack]

nice! I haven't had a chance to go on the computer this weekend, took a little break, so now that's the screenshot... and looking at it, doesn't look like my theory makes much sens... now this patch is supposed to be an example of OSS SYNC as per the operation manual... anyone can tell us why? thanks in advance

[jee_pack]

I'm realy determined to figure this one out, and I realy appreciate that anyone is helping. Thanks a lot to whom posted the screenshot.

Now that I can look at the patch, I'll try to explain what's going on on it to help you guys figure this OSS SYNC thing for everyone who's getting curious about this...

First, if we look at the oss section. The 2 oscilators are active, the first one is a square wave, yes the phase knob is not at 0 but it doesn't change anything as the (o) sign is selected which means there is no subtraction or multiplication happening; the wave form is unchanged. And the second oss is a saw wave with the "(-) sign" modulation applyed. This results in oss 2 being a Pulse Wave form with variable Pulse Width as all you have to do to make is wider or more narrow is change the Phase setting (offset the "invisible wave" by a smaller or larger offset)... To see what oss 2 is doing, look at this picture:


They are both at the same pitch, and the mix knobs says that oss 1's signal is about twice the size off oss 2's signal in amplitude in the mix of both oscilators.

Something interresting though is that there is a tiny bit off FM synthesis, OSS 1 is the carrier and oss 2 is the MODULATOR, so you have a steady square wave, being modulated by a Pulse Wave with variable width and amplitude (see previous picture about that, cuse I'm still not sure about the amplitude thing). Sometimes, the width of the pulse could be wider than the "pulse" in the square wave or it could be "thiner". I don't realy know at this point, but the point is depending on the setting of the Phase knob in Oss 2, it could be either. This is represented in this next picture where the red line is OSS 1's wave and ALL OTHER COLORS ARE POSSIBLE PULSE WAVES FOR OSS 2.


Chances are, because the amplitude of the pulse waves that come from the saw wave are not as high as a normal square wave's amplitudes... and because the mix knob is making the output of OSS 1 twice as strong as the output of OSS 2, the final output is probably mostly just OSS 1. For sure you can hear OSS 2 in the background, but OSS 1 is the one giving the general caracter of the sound... But OSS 1 is just a square wave... Nothing special right? NO! Look at the FM knob, OSS 1 is being modulated by the frequency level of OSS 2. I know the FM knob is almost at "0", but look at the Modulation enveloppe section, this envelope raises the FM level every time the note is triggered and then lets the level decay with the AMP of the note (the Decay setting is high on both the Mod Env and the AMP Env). So that means, the PULSE WAVE, wich has a width that can both extend pass or come shorter than the width of the Square wave, is modulating the Square wave off OSS 1 with FM synthesis, and the result of this FM synthesis is what we mostly here in the final output.

AND the last thing to look at is the fact that in both THE VELOCITY section (completly to the bottom right) and THE MODULATION WHEEL SECTION (completly to the bottom left), there is modulation sent to the PHASE KNOB, which means that whatever the PULSE WIDTH of OSS 2 is, it doesn't necessarly needs to be fixed at this width in order to acheive oss sync. If the mod wheel and velocity settings modifie the PULSE WIDTH, must be that the patch is sort of made to produce OSS SYNC EFFECT, or variations in the feel of THE OSS SYNC, although, staying in the realm of the specific type of sound you get from "Oscilator Syncronization".

Now I still don't understand how this works, the question is: is there a logic to this, or is this a attempt to pretend they can do OSS SYNC while they actually can't, is this just a lie, or Does FM synthesis wich a VARIABLE WIDTH PULSE as the modulator actually sort of the emulation of the OSS SYNC FUNCTION? (Thanks for the help in advance...) and by the way, if your wondering, I have no idea how FM affects a wave, this is not something I totally get, I do know it modulates the frequency of a signal... and I know its a trial and error thing that is mosst likely to work with sine waves.... but that's it....

Thanks for the help!

[Leslie Sanford]

So to demonstrate this, look at this picture:
http://img239.imageshack.us/img239/4622/theoryur4.gif

-On the left side of this picture, you can see oss X which is just a normal square wave that goes through its entire cycle before starting over.
-Underneath that (a), you see that same oss completing 2 cycles in the same amount of time (which I guess is done by have X be one octabe lower than A... but I could be wrong).
-Under that (B,C,D), you see what "A" looks like if you use the (-) sign and the phase offset knob to control the width of the pulse (in this way you can make the pulse width to be anywhere from "0" or "silence" to "the full size" like in A). B,C,D are all different variations of the phase offset knob which result in different Pulse Width.

Next to that, on the right, you see what the total ouptput signal of the synthetiser would look like if you mixed the signal from both oscilators together; always using X as the 1st oscilator and any of the others in the picture as the second oscilator...

Hmm, I may be missing something here. The pictures showing the waveforms added together don't look correct. When the amplitude of both waveforms are +1, the amplitude you get from adding them together will be +2. When the amplitude of one waveform is +1 and the amplitude of the other waveform is -1, the amplitudes cancel each other out, so you get 0. Finally, when both waveforms have an amplitude of -1, the resulting amplitude is -2. What you wind up with in the case of X + a is a staircase looking waveform:

Code: Select all

--+
  |
  +----+          X + a
       |
       +--

I'm jumping in this in the middle of the thread, so I need to go back and read everything to try to understand what you're getting at, though. I may be missing something.

[dusko]

AFAIK reason can't sync the oscillators in subtractor.

Are you sure?

http://www.bassline.wz.cz/syncmania.mp3

[mkastrup]

The patch mentioned is under Subtractor Patches/PolySynths/SyncedUp.zyp

Its not real sync as we know it, its some kind of FM sync.

[Adaerus]

here are better explanations of hard and soft oscillator sync.

ttp://www.synthesizers.com/pmwiki/pmwiki.php? ... ry.OscSync

Here is an actual oscilloscope showing both the master and slave oscillators.

http://www.synthesizers.com/pmwiki/pmwi ... ScopeShots

[jee_pack]

after trying hard to understand this through this thread, I came to agree with what you just said. I'm not realy dissapointed by the fact that it doesn't have oss sync cuse it has a lot of other possibilities that other synths don't have... but I'm dissapointed about the fact that the user manual claims that its OSS SYNC. Reason should not be affraid of saying their program has limits, cuse its still a very very good program to me. and perhaps instead of pretending it can do things it can't do, it should concentrate on developping new devices that can do these things for future versions... anyways, that's a different topic

[mistertoast]

The bear claw and the barber shop trimmer are interesting. I didn't know you could get effects like that. I should rethink the osc sync in my synth to get that shit.

[mistertoast]

>>the user manual claims that its OSS SYNC

So maybe it has OSS sync instead of osc sync.

[jee_pack]

I'm not sure I understand, I mean I know oscilators doesn't take to "S"s but I some how beleive (if my memory is correct) that its writen: OSS SYNC instead of OSC SYNC in the manual... But I could be totally off, my first language is french so sometimes I mix up the letters in terms I don't often write, like oscilators, I always seem to write osscilator before I correct it.... WHAT DO YOU THIN? Does OSS SYNC, mean something else than OSC SYNC? or was that just a joke?

[BertKoor]

LFO1 (low freq oscillator, used for modulation) has a sync option. So it starts at the same point when a note starts instead of running free. Maybe that's what you read in the manual?

And I think the guys were just having fun about OSS sync. There's no such thing...

[mistertoast]

Yeah, the term is osc sync. I think you just misread it. Didn't mean to pick on you. I have great respect for the multilingual.

I was a magazine editor for years, so I correct everyone. My rule on the Internet (usually) is I only correct when the same mistake is made twice, because god knows I have enough brain farts and typos when I type.