[sdiy] Moogey jitter

[Ian Fritz]

Kenneth --  (inline)

>The link below is a magical moogy sawtooth wave spliced into a cold,
>perfect, digitally stable, un-antialiased sawtooth generated in CoodEdit.
>It switches back and forth several times.  Remember, this is the most
>extreme difference in the world theoretically.  But there is virtually no
>audible difference.  Note, I have already gone through the work of measuring
>jitter in a moog waveform and posted the results on AH along time ago.  I
>did it down to about 1/32 of a sample of resolution.  Since the modern
>Technosaurus oscillators had three times the amount of jitter than the Moog
>did, that must mean the Technosaurus sound more Moogy than the Moog.  I
>don't suppose Keven mentioned that.  Measuring jitter means nothing unless
>one compares it to other analogs.
>
>http://home.att.net/~elhardt5/Sawtooths.wav

Thanks I'll have a look/listen.  I tried to read the old AH debate, but it 
seems the first part of it is gone because of a problem with the 
archives.  I have a couple of SSM 2033 VCOs in my system.  They show some 
jitter on a scope, which turns out to be caused by the temperature 
servo.  I know this because the noise goes away when I disconnect the 
servo.  But just listening to a mid-audio wave I don't hear any 
difference.  If I tune the frequency above audible then I can hear a weak 
grungy signal from the servo, so I know it's working in the audio 
range.  But the noise (or jitter, if you will) doesn't make it sound any 
"warmer" to me.


>Jason Proctor writes:
> >>oh no let's not get into that again. search the AH archives for the
>endless flamewars where kevin claims Moog magic this and Moog magic
>that and ken then posts debunking information and it just goes round
>and round and round.<<
>
>When you're dealing with somebody so unreasonable that he thinks speculation
>and myths hold up better than actual measurements, what are you going to do.

Plus, he posts bogus measurements to try to make himself look 
scientific.  That's what annoyed me about that exchange.

>He's never admitted to even listening to my audio files, and anybody can do
>their own jitter measurements from the file above as long as they have a
>sound program that uses calculus to interpolate pitch-downed waveforms for
>sub-sample measurements.  It's all right there in the open.  I can't believe
>he keeps beating this dead horse.

I did read that part of the thread.  His answer seemed to be that bandwidth 
limiting, digitizing and e-mailing(!) makes the magical warmth disappear.

Well, despite all that -- and to get back more on topic -- there are 
irregularities in acoustic instrument waveforms, and it can be argued that 
they do contribute to the character of the sound.  But it doesn't seem easy 
to simulate them by modulating a VCO.  I think this is worth more work.  As 
I mentioned before, I can add these into my Roland rompler sounds and to my 
ear it sounds good.  So we should be able to figure this out.

   Ian