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Extremely high-frequency Oscillator
Posted: Wed May 20, 2020 4:00 pm
by wavemechanic
Are there any modules that can provide sine waves near the nyquist frequency of the DAW? I want to work at 96 kHz and have a carrier wave around 40 kHz in order to emulate terrestrial radio carrier waves.
Re: Extremely high-frequency Oscillator
Posted: Wed May 20, 2020 6:47 pm
by wavemechanic
In the interim, is there a frequency multiplier that can be applied to the output of an OSC that can take the frequency up to 30 kHz at least? Been hunting through the modules, but not having any luck.
Re: Extremely high-frequency Oscillator
Posted: Thu May 21, 2020 2:28 am
by wavemechanic
Heyyyyyy... Andrew Macaulay got me where I needed to go. His Pitch Transpose module goes 5 octaves per knob, and each knob can be chained in series. It's working great for this carrier wave signal idea!
https://andrewmacaulaymusic.uk/modules/ ... transpose/
Re: Extremely high-frequency Oscillator
Posted: Thu May 21, 2020 7:36 am
by wavemechanic
And here is a result of this experiment.
Re: Extremely high-frequency Oscillator
Posted: Fri May 22, 2020 12:34 am
by MRBarton
Voltage Modular runs at 48KHz, so it's physically impossible to represent a frequency higher than 24KHz. Impossible. So the effect you're hearing is probably just the result of aliasing or strange beating. Take it from an old ham, the effect I think you're after is provided directly by a frequency shifter. Find mine here:
https://store.cherryaudio.com/modules/l ... cy-shifter
Part of the Laboratory Bundle. Try everything free for a week and don't forget the free preset packs. You will likey.
thanks.
Re: Extremely high-frequency Oscillator
Posted: Sun May 24, 2020 5:35 am
by andro
You are absolutely right MRB. Since aliasing above Nyquist frequency folds back down, that is what would be heard. Observe it on a spectrum analyzer.
I have all the MRB modules. Excellent!
[From another old ham - what technical people did before computers came along.]
Re: Extremely high-frequency Oscillator
Posted: Sun May 24, 2020 8:59 am
by wavemechanic
I'm not suggesting that my workaround is outside of the audible range, quite the contrary, actually. Since I've been able to completely null the carrier signal, it doesn't matter what frequency I have it at, other than the fact that lower frequencies give more lo-fi effects, another fringe benefit. Ultimately, moving through a dozen or more octaves, gives me a huge range of characteristics in the re-voicing of the original audio. Interesting about VM working at 48, even though the DAW is 96. I'd forgotten that, so thanks for the reminder.
The effect I was looking for is not a frequency shifter, though I had already added one to the modulating signal to recreate the movement of the radio dial and the effect that has on the voice. So good call, but the amplitude modulation of a carrier wave is the key component of what I was after.