[sdiy] When building a White Noise module has anyone ......

[harrybissell]

One idea...

Power the noise module, alone... from a couple of batteries.

Remove it entierly from the modular, and hook it up with only
two wires... a ground and a signal.  One shielded cable should
be sufficient.

If your problems go away... you have power supply or grounding
issues.

If they don't go away... you have something VERY strange in your
noise module.

You migth try the noise module with only ONE wire... the ground.

You can try your noise module with NO wires.

(I once showed a manufacturer that I could noise hit their solid
state relay modules through the air... but totally floating their
module and making a noise spike nearby.  They had been blaming EVERYONE
else for the problem for months. After that, they went home quietly
and fixed their sh!t !!!)

Where can you see the noise on the scope ???

H^) harry


"Rykhaard D.A.M.I.A.N." wrote:
> 
> had it emitting noise, all over the place - through the air??
> 
> I just flipped on the power to my modular, to test out a new (to me)
> noise circuit from René Schmitz.
> Hooking up the roughly 2' banana patch cable to a VCF input, I get a
> lower level white noise emitting all over the place. :O
> Even with the Cutoff on the Filter down all of the way, and the input
> to my VCA, down all of the way.
> 
> Another odd thing with it - the output level of the VCA, when it's
> between about 10AM and 2PM is when I hear the noise.  Outside of those
> settings on the VCA's output control - I hear nothing.
> 
> ???
> 
> Outside of hooking up the WN module's output with a shielded cable, I
> am STUMPED.  I've never had this happen before, with any other noise
> module, that I've hard working. :O
> 
> Any ideas??
> 
> If it would help any - I have 0.1uF cap power supply filters all over
> the board, as well as 100uF and 22 ohm resistors, on the V+ and V-
> inputs to the entire board.
> 
> Thanks for any possible info, on this one. :O :)
> If it's not easy to fix - I could still keep it on the board, for a
> source to the Sample & Hold on the same PCB.  The noise is barely
> perceptible on the power lines, at 20mV.  Seeing that though - maybe I
> should apply cap filters to the PS inputs on the dual opamp, in the
> noise unit.
> Off to investigate. :)
> 
> --
> Take care,
> Warmth and Peace,
> Ryk
> 
> http://deathlehem.bravehost.com/damian.html - D.A.M.I.A.N.;s webpage -
> Jan. 0406 update