Trying to understand Note Number as a Modulation Source

[philroyjenkins]

Hey guys, somewhat new to synths and got a Rev2 as my first.

I'm taking my time and slowly going through little bits at a time and taking a scientific approach to each parameter and function.

I'm messing with the note number as a modulation source right now and I am having trouble controlling it and understanding exactly whats going on.

Is there a preset range on it, lets say c1 to c5, where the change happens? What am I controlling when I do the amount.

Is there anything I can do to shorten the range this effect happens? I am currently making a one patch drum kit and trying to keytrack a few parameters from 0 to 100% over the course of maybe 3 octaves.

[Gerry Havinga]

Hey guys, somewhat new to synths and got a Rev2 as my first.

I'm taking my time and slowly going through little bits at a time and taking a scientific approach to each parameter and function.

I'm messing with the note number as a modulation source right now and I am having trouble controlling it and understanding exactly whats going on.

Is there a preset range on it, lets say c1 to c5, where the change happens? What am I controlling when I do the amount.

Is there anything I can do to shorten the range this effect happens? I am currently making a one patch drum kit and trying to keytrack a few parameters from 0 to 100% over the course of maybe 3 octaves.

Welcome philroyjenkins,

There is a whole world to learn about CV (Control Voltages), gates (voltage based note / event triggering) and step sequencing. I suggest you have a look at the following two Wikipedia articles, analogue sequencers: https://en.wikipedia.org/wiki/Analog_sequencer and CV/gate: https://en.wikipedia.org/wiki/CV/gate

The gated step sequencer is one of the reasons I bought the Rev2 as I am very interested in the synthesizer music created in the 70s and 80s (Tangerine Dream, Klaus Schulze - Berlin School style). In those days, before MIDI, oscillators and modulation tools were mainly controlled by voltages and trigger signals. The gated step sequencer included in the Rev2 kind of emulates this design principle. Each of the 4 tracks can be used to affect a (valid) modulation destination in time when playing a note or a chord. Oscillator pitch (notes) is only one possibility. Pages 46 and 47 give a short succinct overview of how the Rev2 gated sequencer behaves.

The gated sequencer triggers an envelope for half the steps duration. As far as I can see this is related to the BPM/MIDI clock. The destination envelope controls what happens when it is triggered, not the sequencer itself. The slew parameter on tracks 2 and 4 can affect transition in values between two steps. I need to investigate this in more detail but my current understanding of the value parameter is that it generates a relative change. So if the destination source is set to oscillator frequency the value indicates an offset from the keyboard key (or MIDI note) played. The example in the manual, page 49 under the header Normal for Mode, states that if the value is set to C0 the note that is gated will be exactly the note you play on the keyboard or sent via MIDI. Any other (non C0) value will be treated as an offset - which makes it so much fun as this is how analogue sequencers can be configured as well.

I only got my Rev2 a few weeks ago and I've been on a family vacation, so I am just getting into programming the Rev2. I hope I will be able to exercise my theoretical understanding this weekend and figure out exactly how the gated sequencer for the Rev2 works.

Keep visiting the forum, the learning process is part of the fun 

[chysn]

Is there a preset range on it, lets say c1 to c5, where the change happens? What am I controlling when I do the amount.

My understanding of this architecture (DSI Prophet/Mopho/Tetra) is that modulation simply adds quantities to the target parameter. That is, if your cutoff frequency is 40, and note number is assigned to cutoff frequency, and the synth receives note #60 (middle C), then the cutoff frequency would be at 100 (provided no other modulations are in effect, and the Amount parameter is at 100%). Note number is a linear modulation source.

The Amount parameter will attenuate the affect. I think it's used as a coefficient for multiplication to get the final value.

The modulation cannot be constrained to a specific note range. For this, the architecture would need to offer an "offset" parameter. Used in conjunction with the scaling parameter (Amount), you could shift modulation values around a specific point. Unfortunately, that's not available here. What you can try is to use a second modulation source as a substitute offset. Good candidates would be modulation wheel (because it stays where you put it) and expression pedal (same reason). A single-step sequence might also work.

[philroyjenkins]

Thanks for the info guys. I was specifically referring to the Modulation Matrix use of the note number as Chysn was describing but I'll definitely be looking into the sequencer at some point as well.

Chysn, you mentioned some kind of offset parameter. I think the DC modulation source functions as something of this sort. I'll have to play with it some more!

[Gerry Havinga]

Thanks for the info guys. I was specifically referring to the Modulation Matrix use of the note number as Chysn was describing but I'll definitely be looking into the sequencer at some point as well.

Chysn, you mentioned some kind of offset parameter. I think the DC modulation source functions as something of this sort. I'll have to play with it some more!

Ah it didn't occur to me to look into that 

I have noticed one patch (Dull Vox Stereo F1P55) that used the DC modulation source to hard pan one oscillator left and the other right (positive and negative values 127).

[philroyjenkins]

DC modulation source to hard pan one oscillator left and the other right (positive and negative values 127).

Ah very interesting. I noticed there wasn't a great way to get to pan as the Pan Spread on the surface functions differently (bouncing each voice respectively.)

When you hold the LFO button and set PAN SPREAD as the destination, you are actually controlling the left right pan, not the pan spread as you'd think.

All in all, I think it will be some time the capabilities of this box are fully realized.

[Gerry Havinga]

DC modulation source to hard pan one oscillator left and the other right (positive and negative values 127).

Ah very interesting. I noticed there wasn't a great way to get to pan as the Pan Spread on the surface functions differently (bouncing each voice respectively.)

When you hold the LFO button and set PAN SPREAD as the destination, you are actually controlling the left right pan, not the pan spread as you'd think.

All in all, I think it will be some time the capabilities of this box are fully realized.

I believe that is the purpose of the modulation parameter in the matrix:  it can be set to positive or negative values.

[chysn]

Chysn, you mentioned some kind of offset parameter. I think the DC modulation source functions as something of this sort. I'll have to play with it some more!

Oh, yeah, cool. I knew that the Pro2 had a DC offset source, but I did not realize that it was added to the Rev2. There you go, then!

[philroyjenkins]

Oh, yeah, cool. I knew that the Pro2 had a DC offset source, but I did not realize that it was added to the Rev2. There you go, then!

Update, I've kind of managed to get where I need to be. It appears that stacking the same note tracked modulation does decrease the range so long as you offset the initial start point with the DC. For example.

I can stack 3 note number modulations for 127 noise AMT and get a 3 octave range from 0 noise to full noise. To get to no noise, however, you have to transpose down to the lowest option as it seems the note range likes to start from there.

To circumvent this, I use the DC to actually set the noise value into the negative which seems to shift the start point up higher.

If anyone can elaborate on these ideas I'd appreciate it as the grasp on this I do have is very limited. Although its been super fun approaching this almost scientifically and just doing experiments to test the tools I have available to me on the synth.

The goal here is still to make a drum kit with at kick/snare/hats in one patch (just like this vid ) the extended ranged of the REV2's default note number spread makes it tough since I use up a lot of modulations just getting the keyboard range I want.

I'd also like to use that same note number modulation for other things like decay, high pass, resonance, all kinds of stuff. so that makes it tough when each modulation needs to be multiplied by 4.

I have another idea I need to try soon. The Rev2 has alternate tunings and supports adding your own. I'm not sure where the note number for the modulation source is detected from, but I have a feeling its the actual midi note number. So basically if I make a new "tuning" for the REV2 that spans 5 octaves in the space of 1 or two octaves, I might just be able to achieve the effect I am looking for without wasting precious modulations! (Now if only you could save tuning on a patch by patch basis. )

I'm still new to synths but this kind of power and environment for problem solving is what attracted me to the REV2 from the start.

Edit: I realized making a new sysex tuning file wasn't as straight forward as I thought. If anyone is familiar with this and wouldn't mind lending me a hand, let me know.

[extempo]

Edit: I realized making a new sysex tuning file wasn't as straight forward as I thought. If anyone is familiar with this and wouldn't mind lending me a hand, let me know.

There's some info here that can help point you in the right direction: http://forum.davesmithinstruments.com/index.php/topic,108.msg1182.html#msg1182

Alternate tunings have been discussed in threads for other instruments, and it may be worth your effort to do a generalized search of the forum to glean some more information. Changing the Device ID byte is all you would need to do to load a tuning sysex file created for the Prophet 12 into the Prophet Rev2, for example.

[philroyjenkins]

Edit: I realized making a new sysex tuning file wasn't as straight forward as I thought. If anyone is familiar with this and wouldn't mind lending me a hand, let me know.

There's some info here that can help point you in the right direction: http://forum.davesmithinstruments.com/index.php/topic,108.msg1182.html#msg1182

Alternate tunings have been discussed in threads for other instruments, and it may be worth your effort to do a generalized search of the forum to glean some more information. Changing the Device ID byte is all you would need to do to load a tuning sysex file created for the Prophet 12 into the Prophet Rev2, for example.

Found a swell dude who helped me make a sysex file with the desire tuning. Now I'm just working to get it onboard the rev2. If all goes well I'l post back w an example of my 2 octave drum patch with exaggerated modulations!