MOTM

>well would you believe it - last night some mad woman punched me in the
face
>for LOOKING LIKE an ex member of Clock DVA. I suppose it's a good job all
>round that i found this hillarious at the time (tho my bent nose and thick
>lip wouldn't agree)

Beats getting sued for child support.

>how synthesisers work, and then i got stuck on the niggly specifics of
noise
>now then - is white noise (of the kind created by motm#100) true random
>noise as opposed to psuedo-random noise which would be created by a
>microprocessor based or more specifically - korg trinity - system
>or am i totally wrong and should get punched out again..?
>

a) Anybody buying a Trimity over a MOTM deserves to get punched out
b) Yes, you are correct! MOTM uses the amplified "thermal noise" of a Zener
diode
to generate the white noise. A "digital" noise generator uses a shift
register, with
specific stages fedback, to make a repeating pattern.

Sidebar: This fact is used as an (in) famous EE quiz question:

Q: How do you measure the value of a resistor without passing *any* current
through it?
A: Measure the RMS noise voltage (there is a simple equation that correlates
R to Vnoise and temperature).

Now, the repeat time is based on the length of the shift register and how
fast you clock it.
Can't speat for the Triton, but National Semiconductor used to make a little
8-pin DIP
part that did this. Was in MemoryMoog and others. Turns out, the repeat time
was short
(like 5 seconds) and you could "train yourself" to detect the cyclic nature.
So Moog had to issue
a little kluge board with 2 of these, each clocked at a different rate, then
gated together. This
"scrambled" the sequence and got rid of the issue.

But the thermal noise is always "purer" (pure noise??!?). In fact, there is
a small US company
that all it makes is a Noise Diode. This is a special Zener that is made so
the thermal noise
is not suppressed (because noise in a power sipply is generally  *bad*). I
was going to use one in MOTM
but they are about $18ea and too esoteric.

Analog purists strike again!

Paul S.