Hi,
Have been playing about with FM a bit inspired by the patch contest and had a couple of questions..
1. When reading about FM there's much reference to 'FM feedback', ie the carrier signal modulating itself as well as being modulated by the modulater(!) Am I correct in my understanding that this is not possible with Zebra, each FMO is either modulated by itself or the modulater (input)?
2. If I create two duplicate FMOs and set the first to be modulated by the second, why does this sound different to the first modulating itself, switching the input mode from 'self' to 'input' changes the sound dramatically where I'd logically expect it to stay the same?
cheers
Noob FM Questions - FM Feedback
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- KVRist
- 43 posts since 7 Oct, 2002
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- u-he
- 30219 posts since 8 Aug, 2002 from Berlin
Yes, an FMO can either be FMed by another module, or by itself.
When modulated by itself then the FMO *adds* to the signal flow like a normal oscillator does. Thus you also hear the input signal.
When it's modulated by the input signal, it acts like a filter, and the input signal isn't run through.
Urs
When modulated by itself then the FMO *adds* to the signal flow like a normal oscillator does. Thus you also hear the input signal.
When it's modulated by the input signal, it acts like a filter, and the input signal isn't run through.
Urs-
- u-he
- 30219 posts since 8 Aug, 2002 from Berlin
Note that, when I came up with this, I did a lot of experiments with FMOs modulating itself and being modulated by something else at the same time. I found these modulations hard to control and generally not too useful, hence I ditched that in favour of a more simple system.
IIRC non of the DX-7 algorithms have feedback *and* modulator inputs. There are just some algorithms that have feedback spanning over 2 or 3 operators.
IIRC non of the DX-7 algorithms have feedback *and* modulator inputs. There are just some algorithms that have feedback spanning over 2 or 3 operators.
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- KVRist
- Topic Starter
- 43 posts since 7 Oct, 2002
OK, thanks URS. Is this the reason for the '+' in FM self/self2 mode?Urs wrote:Yes, an FMO can either be FMed by another module, or by itself.
When modulated by itself then the FMO *adds* to the signal flow like a normal oscillator does. Thus you also hear the input signal.
Is there any likelihood of adding FM modes whereby the oscillators self-modulate but you only hear the modulated signal (without the '+' ) - I think this would be quite useful.
Then again, I've only really been using FM for a couple of days
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- KVRAF
- 4197 posts since 23 May, 2004 from Bad Vilbel, Germany
Yeah - what does the '+' signify?muleskinner wrote:Is this the reason for the '+' in FM self/self2 mode?
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- u-he
- 30219 posts since 8 Aug, 2002 from Berlin
They "add" rather than "replace". The input signal is let through. At least, that's what I was thinking back then.Howard wrote:Yeah - what does the '+' signify?muleskinner wrote:Is this the reason for the '+' in FM self/self2 mode?