[sdiy] analog loses another niche

[ChristianH]

Um, that's a tough one.

Let's see - you'd need a real noise source (any BBD will do), a filter,
a VCA, a complex waveform LFO, maybe some additional FX to mess up the
signal. 

Ok, if you have plenty of board space, it could be done. 
Maybe even with VC'd chuff rate...

Chris (did I actually feed the troll...? ;-)



On Thu, 1 Jul 2010 11:15:49 -0400 (EDT) Harry Bissell
<harrybissell at wowway.com> wrote:

> has anyone tried to clone the MM5837 ???
> 
> </troll>
> 
> H^) harry
> 
> 
> ----- Original Message -----
> From: Scott Gravenhorst <music.maker at gte.net>
> To: synth-diy at dropmix.xs4all.nl
> Sent: Thu, 01 Jul 2010 10:54:19 -0400 (EDT)
> Subject: Re: [sdiy] analog loses another niche
> 
> Tim Ressel <madhun2001 at yahoo.com> wrote:
> >One fine day I got clever and hooked up a LFSR to an RF spectrum 
> >analyzer. I thought with averaging turned on I would see a 
> >straight line. Instead what I saw was a picket fence of peaks, or 
> >in RF parlance, a comb generator. With an 8-bit LFSR the peaks 
> >were quite pronounced, with a 16-bit they were so close together 
> >it was tough to see them, but they were there. Bottom line: 
> >digital noise really does sound different, unlike CDs that have 
> >been purified with flashing LEDs. 
> 
> I have an image file somewhere with the spectra of different waveforms, LFSR output was one
> of them and yes, it's a picket fence sort of thing and as you wrote, the longer the
> register, the closer the pickets.  According to another poster from some time back, this is
> predictable and can be calculated (Magnus perhaps?).  
> 
> In my experimentation, I've been using LFSRs of 64 or more bits.  IMO, with such a long
> LFSR run at very high rates, the noise is, to me, indestinguishable from a good analog
> noise generator.  As I said: IMO.  And dare I write that with such long LFSRs is it
> possible that a digital noise generator could actually sound better than an analog noise
> generator?  I think so - IMO.
> 
> Scott (LFSR) G.
> 
> 
> 
> >----- Original Message ----
> >From: "jays at aracnet.com" <jays at aracnet.com>
> >To: Synth DIY <synth-diy at dropmix.xs4all.nl>
> >Sent: Wed, June 30, 2010 4:32:13 PM
> >Subject: Re: [sdiy] analog loses another niche
> >
> >I wonder is an analog source any better than some form or 
> >combination of pseudo-random long length LFSRs? 
> >
> >Jay S.
> >
> >Tom Corbitt wrote:
> >
> >> http://spectrum.ieee.org/computing/hardware/intel-makes-a-digital-coin-toss=
> >> er-for-future-processors
> >> 
> >> =94Historically, RNGs have been analog,=94 says Greg Taylor, director of
> >> the Circuit Research Lab. =94But porting to smaller technology nodes
> >> [with analog devices] requires a lot of fine-tuning that is
> >> unnecessary with digital versions.=94
> >> 
> >> Be interesting to see how they rigged the metastability to be a 50/50 shot.