LFO mod

[DrWashington]

OK, this can't be right...

I'm trying something pretty simple here, least it should be:

I've got a comb filter as my audio source (oscillator, basically), and I'm simply trying to use an LFO to modulate the tune for vibrato. I want said vibrato to respond to aftertouch intensity.

Problem is, if the LFO amp is all the way down, as it should be, the mod slot to the immediate right won't affect it at all. I have aftertouch in that slot. If I turn up the amp knob a little (which I don't want to do, as I want the tone to remain pure and constant unless I'm applying aftertouch), I can affect it with aftertouch, but in some weird, exponential way that doesn't make any sense. This should be really easy... no amp normally, w/ AT press, LFO amp increases, which in turn modulates comb filter.

What am I doing wrong???

[xh3rv]

The ModMatrix should help here - you can assign the LFO amp to a slot and modulate with AfterTouch. Or something close to that, if I didn't understand what you were after exactly.

[DrWashington]

Tried that; no dice.

[xh3rv]

Tried that; no dice.

I just read your post a little more carefully - have you tried using aftertouch in both the 'modulate' and 'via' knobs? If not or that doesn't work, I'll stop giving bad advice

[bmrzycki]

This is one of the weirder modulations in Zebra and it surprised me the first time I saw it as well, I believe on one of Howard's presets.

First, set the LFO Amp Mod slot to ATouch, set its value to 100.00. Now, scale the amount of LFO 1 Amp you want, from 0 to 100. 0 Amp is off, 100 amp is full. You can also attenuate the vibrato amount on the comb Vibrato source too.

For this modulation it's "reversed" from how you expect.

[AL321]

Problem is, if the LFO amp is all the way down, as it should be, the mod slot to the immediate right won't affect it at all.

This isn't just related to aftertouch either.

Just under the module panel, turn the voice mix for channel 1 to zero, and assign MSEG1 to the voice volume. Now turn the MSEG assignment to 100. You would think that the MSEG can now raise the volume, but like you say, it doesn't. It stays silent, until you raise the volume a little bit.
Maybe Zebra has to use ratios, rather than fixed values, to deal with all the complex modulation options available (just a guess).

[Breeze]

This isn't just related to aftertouch either.

Just under the module panel, turn the voice mix for channel 1 to zero, and assign MSEG1 to the voice volume. Now turn the MSEG assignment to 100. You would think that the MSEG can now raise the volume, but like you say, it doesn't. It stays silent, until you raise the volume a little bit.
Maybe Zebra has to use ratios, rather than fixed values, to deal with all the complex modulation options available (just a guess).

I find this odd too, but another workaround (other than the Matrix) is to set the Volume at 100% and modulate it with the MSEG at -100, and then use the MSEG backwards (visually high values = 0 and vice versa). There doesn't seem to be a way to make the volume go to 0 using a normal positive MSEG. But it's not a multiplier because the MSEG effect at + max doesn't change with the volume adjustment; it's as though the volume is at some nominal level that can still be influenced by positive excursions of the MSEG. The inverted mode described above does work as expected. The only reason I can think of why it's this way is that it gives you access to two behaviors instead of an inverted version of the same one, although I would have preferred to see it implemented the other way as it's the more common usage. Could just be a bug...

[DrWashington]

Thanks everyone... I'll try that. If it's not a bug, it's still awfully odd. I wonder why Urs would make it this way?

Breeze, I agree, it would be much less confusing if it were implemented in a standard manner... one of the reasons I miss my Virus so badly is that it was versatile, sounded great, and was most importantly very straightforward, as well as deep with the mod matrix options. With softsynths, and I use many now, I always feel like I'm trying figure something out. Breaks my zone.

More than anything, I like making music. I'm a helluva synth programmer after all these years of trying, but I want to be able to do it quickly and not have to think about it from one synth to another.

[Urs]

I don't really remember why it was made like that, but it's the same principle as velocity on envelopes: With the Mod Depth Parameter you define how much of the chosen amplitude is controlled by a modulator.

If I recall correctly there was even a practical reason for that, something that may have occurred to me while working on Zoyd maybe. It's long time ago. Maybe it is simply about consistency with Vel2Env, as it's meant to be "Mod2LFO" rather than "Mod2LfoAmp". Maybe it's because the separate LFO Amplitude control came in later, or maybe the reason is that otherwise the LFO delay couldn't be implemented consitently.

Thinking about it, I'm sure that Zebra 1.x hadn't had any LFO Amp (it was always 100%), and it came in later during the process of setting up Zebra2. With the old scheme, it had to be a Mod->Lfo thing as in Vel->Env, and because I wanted to keep it familiar for Zebra 1 users I might have took it over, despite adding a global LFO Amp knob.

Urs

[clangorous]

I realize this is an old post. But old posts are useful to folks searching for answers, so here's my 2 cents.

The settings in the AT Vibrato screenshot below modulate pitch and volume using Aftertouch control. Vibrato should slightly modulate pitch. Volume only vibrato is really tremolo and sounds more like an effect than an instrument.

What this method lacks is a smooth attack and release of the vibrato. Even with a slow application of the Aftertouch, the vibrato attack and release are too quick and it sounds mechanical.

AT Vibrato



BUT, if you use a MSEG, you have more control over the articulation of the vibrato, including attack and release. Here's how.

http://www.kvraudio.com/forum/viewtopic ... 65#5560865

Enjoy,