PINK noise gen

[audiofan]

I expect to build a pink noise generator for speaker testing, below is what I expect to test .. it is not built .. not tested .. yet.

If you see any flaw please comment ....

 

[Mooly]

That looks OK, a very traditional old fashioned type of noise generator using a reverse biased B-E junction. Haven't seen that done in years.

Just a thought... why not use an electronically generated pink noise audio file. Dead easy to make and it would do away with the need for dual supplies for your generator.

 

[audiofan]

I did some work and made modification to the circuit , I am very surprise with the result T1 is a 2N3904 transistor and if I replace it with an other sample ( same number ) I get a complete diffetrent soud !

I dont have a spectrum analyser ... so I cannot know when I really have PINK

I can get many flavor of pink !

 

[Mooly]

That is the big problem... non repeatability.

Here's an electronically generated pink noise file to compare against. You could perhaps check yours by recording it and looking at the spectrum in 'Audacity' which is the program I used here, both to generate the file and to look at the spectrum.

AUDACITY