Amplitude modulation

Elektron Gear Analog Keys/Four
#21

thanks, good to know… seems some things in the sound generators are done in hardware, and some are hybrid, like the suboscillator tunings (as the 5th subosc was added via OS update)?

but as this is off topic, i was wondering, what do you think of something like a technical Q&A session with you guys, regarding the architecture of the Analog Four?

basically a set of questions from the community, and answers from Elektron R&D? Maybe just a separate thread in the forum would do. there’s obviously the risk that it will just end up as a feature wishlist…

well… i know i’ve got some questions about oscillator & filter characteristics, and also some curiosity about what the FPGA does…

#22

The phase of what?
And what should be cancelled out?

#23

Wow, very interesting read!

Let me add some dry theory about AM: http://www.soundonsound.com/sos/mar00/articles/synthsecrets.htm

#24

The phase of what?
And what should be cancelled out?[/quote]

I was thinking if I had LFO A +B with opposite phases modulating the same parameter it’d do “nothing”.

Or I was looking to hear if there would be interesting distortions by modulating phase at audio rates, while already using the LFO at audio rates. It often seems I can only hear phase changes when manually adjusting the setting.

I bring it up because I find that using the LFOs at audio rates on the oscillator’s pitch, pulse width, waveform, anything! really makes the effects of the AM more noticeable.

There are some other things don’t seem to respond to audio rates too? For instance, sync amount doesn’t seem to respond much?

#25

You mean LFO 1 and LFO 2, and setting one them out of phase with 180 degrees?

Provided that you use sine or triangle LFOs (the other ones don’t cancel each other out), and trig the LFOs simultaneously (to give them a well-known phase difference), and modulate the same parameter with the same amount, I’d expect the result to be quite close to nothing, yes. :slight_smile:

What do you expect to hear when modulating sync amount with audio rates? I’d be surprised if it sounded very radical, since sync amount is only used to determine what happens sync-wise when an oscillator resets. Everything that happens to the sync amount between these sparse occasions are irrelevant. :slight_smile:

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#26

Thanks! That makes sense. On further experimentation I was able to hear sync 2->1 amounts at audio rates, but it sounds way cooler using an envelope. :joy:
I was reading about casio phase distortion and want to see if any of that applied… :zonked:
…
With AM sometimes I find it easier use the velocity mod to change the pitch of one (or more) of the oscillators and parameter lock velocity. It’s fun to play with having different pitch depth amounts for each oscillator.

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#27

You can do this if the modulating oscillator is set to pulse or tranny pulse then turn the PW knob anti-clockwise, the further you turn the less you hear the original signal.
In the positive direction, the more you turn the more you hear the original signal, so it’s good for controlling AM amount.

That’s how it works on mine so if it’s malfunctioning I don’t want it fixed!

#28

Thanks for replying to this thread, /mr. It’s always interesting to read about the intricate details of this wonderful machine.

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#29

Loving the AM lately, some great sounds to be found in this complex area of the A4.

#30

Great, I’ve just explored this technique with AM1. Had great results when putting the random LFO on Osc2 pitch…

#31

Here’s a quick snippet of doing Allen Strange’s book AM exercise 8.66 with an A4. http://soundcloud.com/suicidelane/strange-figure-866-a4-implement/s-TzY4s

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#32

Lovely lovely timbres :slight_smile:

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#33

I’m sorry to drag up this old thread, but this quote deserves to be reposted.

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#34

Hehe let me dig this out once again…
What a wonderful area of this amazing synth !

#35

great thread… a lot of input. thanks to all participants.
now i´ve done sounds i never thought one can do with am.
AM its definitely something to experiment and spend time with…
crossed am (am1 + am2), am + syncosc´s, etc.
ACE

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#36

What exercise is this? i have the allen strange book but 8.66 seems to be “timbre cycles”

would love to recreate/work through this.

thanks!

#37

I seem to remember reading somewhere…I just wish I could remember WHERE …but the Analog four mk2…does not ring modulation Um…I. think…Saw…& …Transistor Pulse??? I think it doesn’t AM the waveforms that are not symmetrical… I THINK…I cant find it anywhere in the manual now…but I cannot remember where I read this… but I think maybe thats why people may be complaining it doesn’t AM some of the other waveforms…because its actually only ever supposed to work with PULSE & I think TRIANGLE?? I think?? sorry…

I guess what I mean to say is…I THINK I read somewhere that the A4MK2 doesn’t AM every single type of waveform…its just not capable of doing that…

but I cannot for the life of me remember where…

sorry if thats completely useless information

thanks

renny

#38

Post #14 is from someone at :3lektron: - search the manual against the terms he highlights

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