Circuits for all noise generator

[fpop]

i am trying to find a circuit diagram for a noise generator that can change between all the colours of sound. it is driving me made and was wondering if anybody can help please

 

[Cliff_J]

There was a thread about white noise a little bit ago.

Long story short, you can filter white noise into the other colors.

http://rane.com/par-n.html#noise_color

 

[fpop]

i need to get a circuit diagram for the filters and how to switch between them

 

[berkeman]

i need to get a circuit diagram for the filters and how to switch between them

I googled gyrator audio filter and got lots of hits. Here's a pretty good one to start you off:

http://www.rane.com/note122.html

 

[Cliff_J]

fpop - if you know how to use an opamp then its somewhat simple, you can search for lots of circuit diagrams for filters. You simply switch between the outputs or could build a simple mixer to fade between them.

What is this for?

If you're demonstrating something, a computer with software like Cool Edit (now Adobe Audition or something) will let you generate and filter the signal to your heart's content in seconds and will be very easy to use in comparison.

If you're doing something with audio gear, pink noise is the standard color because of its similarity to human hearing that roughly deems equal power per octave to be a 'flat' response. Look up Fletcher-Munson for a lot more detail on how the amplitude level affects this relationship.

 

[fpop]

i need it for school i have to design and build a white noise generator that can switch between the colours using filters but i think I am out of my depth

 

[Cliff_J]

Sounds a little advanced. I found this diagram and it uses a three op-amps (ignore the bottom half of the pic).
http://www.synthfool.com/schematics/polynoise.gif

You could just use a regular SPDT switch to go between the two colors but would need an output suitable for driving a speaker (if you don't have a power amp) and you also need a power supply for the opamps.

I would think there would be an easier way to accomplish the task.

 

[smilingchick]

I too need http://www.speechprivacysystems.com/white-noise" to sleep and i always use an oscillating fan for years now as the noise of it puts me to sleep easily and also blocks out any background noise at nite i.e. car alarms, train whistle, dog barking etc.