The Official Sequential/Oberheim Forum
SEQUENTIAL/DSI => Prophet => Prophet Rev2 => Topic started by: aeonn on August 02, 2017, 02:57:08 AM
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Hi everyone,
I was playing with the modulation and encountered the last 2 sources of the list but couldn't figure out what it means, so I was hoping that you could help me to understand ?
1 - "DC" : I have no idea what that source is supposed to be... for me DC stands for Direct Current but I doubt it is the right description.
2 - "Audio Out" : it says in the manual that it's the digitized audio used as a source but could someone explain it in detail to better understand its effect on the destination ? Is it something close to Ring Modulation ? Does it mean that the peaks and valleys of the Audio Out waveform is modulating the destination ? So potentially, if the waveform is full of harmonics, this could create some complex modulations ?
Thanks for your help ;)
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DC adds an offset. I think it works like this:
Say you had an LFO triangle set to a value of 5. It's going +/- 5. Set the DC to 12 and route it to the same destination as the LFO and it will now be 12 +/- 5, so instead of going from -5 to +5, it goes from +7 to +17.
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What does DC stand for ?
I don't really get the necessity of such source. If it is supposed to be an offset of the destination value, why not setting it directly from the dedicated knob instead ?
Let's take your example about an LFO going +/- 5. Let's says that my LFO controls the filter cutoff frequency. If adding +12 from the DC offsets the values to go from +7 to +17, I would rather set the Filter Cutoff to +12 directly and it will avoid unnecessarily using a modulation slot.
I am just trying to figure out exactly what the DC is doing. ;)
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I believe it means Direct Current too aeonn. :)
It just adds bias to the signal to make it more linear, just like it does to audio sound cards when you are recording analog gear.. I think its kinda like DC offset on sound cards.
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One place the DC source is very useful is in setting a fixed pan value. Especially useful for layered sounds where the individual layers are panned hard left and right respectively.
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DC does mean Direct Current. 5V DC means constant voltage, but don't worry about the naming. It's just normal in electronics terminology.
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So it's pretty much a static source to set a value to a constant position ? I guess it's useful for the destinations that have no dedicated knobs then.
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What does DC stand for ?
Best description of the DC modulation source is that its a constant value. Perfect for the use cases such as panning when one do not want to rattle the modulation destination.
And in case you want a dont-try-this-at-home illustration of the difference between AC and DC:
https://youtu.be/Zez2r1RPpWY . o O ( :o )
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DC adds an offset. I think it works like this:
Say you had an LFO triangle set to a value of 5. It's going +/- 5. Set the DC to 12 and route it to the same destination as the LFO and it will now be 12 +/- 5, so instead of going from -5 to +5, it goes from +7 to +17.
Interesting...The Prophet/MoPho/Evo architecture really is the closest thing I've seen to modular in a hardwired synth!