Nerd question: Repro-5 noise osc

[Chris-S]

Hi,
I recently watched a video demonstrating the Prophet-5 white noise. This sounded like a sampled noise with a period length of one second or so due to the working of the noise chip.

I do not hear this periodicy in the Repro5 white noise.

Not a big deal, just wondering if this was not known to the devs during the making of RP5.

The video:

https://m.youtube.com/watch?v=bmdazFekz-E

[muki]

interesting...
quoting a comment from the video:

The noise source for this machine is a MM5837N which internally is a 17 bit digital linear feedback shift register with a single feedback tap.

x^{{17}}+x^{{14}}+1 Feedback length of 131,071

This will sound like pseudo random noise in short bursts but will repeat every 131071 clock cycles. This is the cyclic sound that you are hearing.

[Urs]

Hehehe, this isn't how the noise is generated in the Pro-One, and when we did Repro-5 it was initially a polyphonic Pro-One, and when we got hold of a P5, we simply calibrated what was there.

We did figure out the noise generator, but then decided to keep our white noise as it simply sounded better.