[AH] Red noize

[Martin Czech]

:::The trouble with the shift register is that it produces 2**N-1 number of
:::frequencies (at most). These are single frequencies evenly spread appart.
:::XORing with noise will not do very well since the modulation would have a DC
:::term which would let too much of the original waveform thru.
:::

This is true, since it is (at most) a repeating sequence of 2**N-1
samples length, and you think of the DFT of it.
But I think if the sequence is very long (usuall) you can't apply
this DFT model for the hearing result, because the ear-brain machine
seems to do a short time DFT, otherwise the change of spectra 
wouldn't be noticed every 1/20 seconds or so. I  mean a first order
model of the ear-brain would be hopping DFTs with 1/20 s window size.
This would smear , well and give much fewer frequencys.
But each hop would sound slighly different, which makes it sound like noise
and not like a harmonic rich wave...


And XORing with pulses from a diode e.g. will cause a causal impulse response,
so there is correlation... but still the output should be more random
than the shifter allone, really unpredictable.
Consider the case were you use the random source as pitch modulation.
Very time you power up the synth you will hear the same modulation
pattern (I think a POR is needed for the shift register, to avoid
the 0 state, maybe even a false state detector, to avoid getting trapped).
Using some extra noise will certainly give more variety.

:::> 2nd Idea:
:::> 
:::> I've read about mathematical theory about poles with rational order,
:::> or in general network transfer functions with non integer order.
:::> 
:::> There is no reason why math should prefer x**2 instead of x**2.18973,
:::> we do this every day using the pocket calculator.
:::> Has anything useable grown out of this roots since 1970??
:::
:::Actuall, there are good reasons for some restrictions of that sort. It is
:::still a mystery how the Columbs law of fources between two round objects
:::being electrically charged could be so accurate on r**2. It was simple
:::reasoning behind that and the conclusion has hold for remearsurements to the
:::16thies digit without disturbance in the force.
:::

Sure the laws of physics seem to be against it (today).
But math has nothing to do with the real world since long...


m.c.