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mrpv
Joined: Aug 06, 2007 Posts: 8 Location: montreal
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Posted: Tue Aug 14, 2007 7:04 pm Post subject:
Change the Phase of a Saw Oscillator |
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Hi, I hope somebody will be able to help me. I'm trying to reproduce a sound I use on another synth. The key element about my patch is that there is two Saw oscillators with one slightly phased (dephased?) from the other. Is there a way to do that with the Modular?
I have OscA set to Saw and a Slave Saw Osc. I want the OscA to have a different phase.
Also, how could I change the side of the saw. ie. instead of /|, I want |\.
Thanks! |
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Kassen
Janitor
Joined: Jul 06, 2004 Posts: 7678 Location: The Hague, NL
G2 patch files: 3
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Posted: Wed Aug 15, 2007 1:35 pm Post subject:
Re: Change the Phase of a Saw Oscillator |
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mrpv wrote: |
I have OscA set to Saw and a Slave Saw Osc. I want the OscA to have a different phase.
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Modulate the slave's pitch *very* slightly using a slow LFO. Striclty speaking not what you asked for but this is what I think you want. Don't apply this modulation to the master as the slave will follow the master and it's the difference that we're after.
Quote: |
Also, how could I change the side of the saw. ie. instead of /|, I want |\.
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use the level-shifter/inverter (I think that's what it's called?) it would also work to amplify it by -64 units as that comes down to the same thing. _________________ Kassen |
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Mystic Loon
Joined: Jan 13, 2007 Posts: 14 Location: Germany
G2 patch files: 1
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Posted: Wed Aug 15, 2007 2:36 pm Post subject:
Slave pitch modulation only Subject description: How is it done |
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Dear Kassen!
I'm not really an expert on the G1, so forgive the question:
how do you modulate a slave-oscillator's pitch? There is no modulation input there; is it done via AM or FM? Please let me know!
Thank you in advance.
Mystic Loon |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Wed Aug 15, 2007 3:48 pm Post subject:
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FM = Frequency Modulation, frequency and pitch both refer to the same thing, how high or how low the note is. Frequency Modulation however is used for a linear modulation and Pitch Modulation for exponential modulation of the pitch.
AM = Amplitude Modulation and amplitude refers to how loud the tone is.
FM can be used for vibrato and AM for tremolo. Pitch modulation is normally used to track a keyboard.
A slow vibrato, as suggested by Kassen will make the frequencies of the two oscillators dance around each other and in doing so the phase relation between the two oscillators constantly shifts. This makes the tone come alive a bit. _________________ Jan
also .. could someone please turn down the thermostat a bit.
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ian-s
Joined: Apr 01, 2004 Posts: 2669 Location: Auckland, New Zealand
Audio files: 42
G2 patch files: 626
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Posted: Wed Aug 15, 2007 4:43 pm Post subject:
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I think mrpv may want a variable but fixed phase relationship between the two oscillators. Does adding a constant level before the slave sync input work on the NM1?
Except when used for modulation, there is no audible difference between a positive and negative sawtooth, they just look different. |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Wed Aug 15, 2007 5:25 pm Post subject:
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g2ian wrote: | IDoes adding a constant level before the slave sync input work on the NM1? |
Yes, given a suitable input waveform and polarity ... an inverter is probably needed ... IIRC the saw ramps down and PWM modulates the time of the down going edge. _________________ Jan
also .. could someone please turn down the thermostat a bit.
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mrpv
Joined: Aug 06, 2007 Posts: 8 Location: montreal
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Posted: Wed Aug 15, 2007 10:06 pm Post subject:
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I wonder, if someone could actually "show" me how to do it, because I'm not sure I get what I am supposed to do exactly.
I tried to add a Constant to the slave signal but I think it just changed the pitch. Adding a Constant to the FMA moduator on the slave does something, but I'm not sure it change the phase.
At this point, it's more like I want to understand how to do it, more than I believe that this is what I absolutely need to create my patch.
Thanks... |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Thu Aug 16, 2007 5:10 am Post subject:
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I can't patch now but maybe have a look at the Oscillator Synchronization and the Frequency Modulation workshops at http://www.clavia.se/nordmodular/Modularzone/index.html - this touches the same subject at least. _________________ Jan
also .. could someone please turn down the thermostat a bit.
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Tusker
Joined: Feb 03, 2005 Posts: 110 Location: Texas
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Posted: Mon Aug 20, 2007 6:30 pm Post subject:
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I assume that if I add a constant to a saw wave and waveshape it, I have actually shifted it's phase. Would this be a correct assumption? If not is there a technique which involves adding a constant that could do the phase shift?
I too would like to be able to control phase shift, without necessarily using pitch detune to do it.
Jerry |
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mrpv
Joined: Aug 06, 2007 Posts: 8 Location: montreal
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Posted: Mon Aug 20, 2007 6:41 pm Post subject:
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I remember in a MAX/MSP homework, I was using a Sqr Osc that I could change the phase and by adding or multiplying another wave to it, I was able to creat a Saw. But that was a while ago and I don't remember how that work... and don't have access to max/msp anymore. |
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davep
Joined: Jul 05, 2004 Posts: 467 Location: Oakland, CA
Audio files: 10
G2 patch files: 73
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Posted: Wed Aug 22, 2007 8:05 pm Post subject:
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Yes, you can do modulatable osc phase on the NM1. This topic came up a while ago and I don't remember who figured it out, but it works great. Here's how:
1. Use a regular "up" sawtooth as a sync master osc.
2. Ordinarily, you would connect this directly to the SYNC input of the sync slave osc and the slave osc would reset every time the master saw crosses from negative to positive, in the middle of it's upward ramp.
3. Instead of patching it directly to the slave, connect it to an audio mixer input and connect the mixer output to the slave osc's sync input.
4. Now connect a Constant module or an LFO or any other bipolar control signal to a second input of the mixer. Turn up the level, but always keep it at least a little lower than the level of the audio sawtooth osc.
5. This control signal will now 'bias' the audio sawtooth master osc waveform positive and negative, which changes to point at which it crosses the zero line (negative bias causes the sawtooth to cross zero near the end of it's ramp, positive bias causes it to cross zero near the start of it's ramp).
6. This will now alter the phase relationship of the slave osc to the master osc. And the cool thing is, sync sweep effects still work, but you now also have phase mod / detuning effects. You can build huge aggressive pads by added a couple more slave oscs with separate sync sweeps and separate phase mod mixer + LFO circuits. _________________ Dave Peck |
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Colin OOOD
Joined: Dec 11, 2006 Posts: 22 Location: Bristol, UK
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Posted: Fri Aug 24, 2007 12:18 am Post subject:
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That's fantastic Dave, thanks so much.
Hopefully this isn't a stupid question but it's late, I'm jetlagged so sod it here goes... can this technique also be used to create an oscillator whose start phase can be varied and reset by a note-on event? ie. an oscillator which always starts at eg. 94' when a key is pressed? |
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davep
Joined: Jul 05, 2004 Posts: 467 Location: Oakland, CA
Audio files: 10
G2 patch files: 73
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Posted: Mon Aug 27, 2007 10:33 pm Post subject:
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Colin OOOD wrote: | That's fantastic Dave, thanks so much.
Hopefully this isn't a stupid question but it's late, I'm jetlagged so sod it here goes... can this technique also be used to create an oscillator whose start phase can be varied and reset by a note-on event? ie. an oscillator which always starts at eg. 94' when a key is pressed? |
Hmm. Now THAT's trickier.... So you would want the sync slave osc to be forced to start (reset) at a specific point in it's wave, other than the normal reset start point, when it gets an instantaneous reset signal of some kind..... I'm not sure there's a way to do that. You would have to alter the sync behavior of the slave osc itself, not just modify the signal from the master osc being used as the sync master.
But I'm not sure why you would need to do this. The phase mod trick described in the posts above is only useful because it provides a way to change the phase relation of the master & slave osc over time, like slowly shifting the phase with an LFO, creating detuning effects along with sync sweep. Would forcing the slave osc to reset at a specific static point in it's wave (instead of the normal start point) provide a useful effect? _________________ Dave Peck |
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Colin OOOD
Joined: Dec 11, 2006 Posts: 22 Location: Bristol, UK
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Posted: Tue Aug 28, 2007 5:58 pm Post subject:
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davep wrote: | Colin OOOD wrote: | That's fantastic Dave, thanks so much.
Hopefully this isn't a stupid question but it's late, I'm jetlagged so sod it here goes... can this technique also be used to create an oscillator whose start phase can be varied and reset by a note-on event? ie. an oscillator which always starts at eg. 94' when a key is pressed? |
Hmm. Now THAT's trickier.... So you would want the sync slave osc to be forced to start (reset) at a specific point in it's wave, other than the normal reset start point, when it gets an instantaneous reset signal of some kind..... I'm not sure there's a way to do that. You would have to alter the sync behavior of the slave osc itself, not just modify the signal from the master osc being used as the sync master.
But I'm not sure why you would need to do this. The phase mod trick described in the posts above is only useful because it provides a way to change the phase relation of the master & slave osc over time, like slowly shifting the phase with an LFO, creating detuning effects along with sync sweep. Would forcing the slave osc to reset at a specific static point in it's wave (instead of the normal start point) provide a useful effect? |
I think I was a bit unclear I'm not talking about a sync slave oscillator, I'd just like a keyboard-resettable oscillator with variable start phase as is available on many other synths, both hardware and software. Perhaps it's not possible on the NM1, and I should stick to the VSTis I have that give me this facility, but I use this it a lot when making basslines and it would be great to get the Nord's chunkiness on the case |
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ian-s
Joined: Apr 01, 2004 Posts: 2669 Location: Auckland, New Zealand
Audio files: 42
G2 patch files: 626
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