I’m all in on the topic of this video. I hate to depend on a phone app or software on my laptop to do basic tests, unless I need a printout. I just think I could really use a pink noise generator along with my old analog RadioShack Sound Level Meter to start dialing in my speakers, adjusting my room EQ device, setting sound levels for AB testing of speakers, amps, sources, etc. It just seems like a very useful device for me right now.
I once saw an article about a better analog noise generator. It may have been an application note by B & K (Bruel & Kjaer) or somebody else. But the core idea was that the single transistor noise source provides more unpleasant noise than necessary. You should utilize two transistors, one avalanching on positive voltage and the other one on negative voltage. Then you add the two individual noises and get a balanced noise. I think that the experience is like having all (odd and even) harmonics in a distorted signal, rather than mostly even harmonics..But I may already remember wrong. Anyway, the summing of the two sources requires one or two DC blocking capacitors and two identical resistors feeding the two signals to the inverting input of an op-amp and the resulting “better” noise is available at the op-amp output.. This is of course still white noise. BUT, another noise source I have once seen used a CMOS op-amp CA3130 (originally from RCA) at a reduced power rail voltage that maximized the noise - and surprise, it produced PINK noise without further filtering! Finally, James G. Holbrook in his book Laplace Transforms for Electronic Engineers - Second edition 1966, Library of Congress Catalog Card 59-12607 - has a thorough treatise of synthesizing the white to pink noise filter, starting around page 254. He also has other applications for the synthesized circuit. Just for anybody (possibly?) curious.
Awesome, I would like you to demo the scope some more please and I have used noise to measure frequency response and it's quite intuitive it seems obvious when you get into it. Good stuff........cheers!
I have a Panasonic white, pink and brown noise generator from the 1980's. I think it was actually made by Matsushita. All of the print on it is in Japanese and I had to get a friend translate it for me. Got it on eBay Japan which I might add is a great place to pick up vintage Japanese electronics and test equipment.
@@josephlalock8378 LOL, I realize that. Point was it was made in house and not by another company for them. I have some analog meters labeled Matsushita and some Panasonic. Exact same meter but different silk screened faceplate.
As soon as I clicked the ad that played was some political mayor peet guy propaganda and it struck as so funny the gulp of coffee spewed out with a large belly laugh - thanks utoob digital commedy algo 🤣
Hi Tony, I have an interest in your stabilizer device that demands a story about a possible use. In the 80’s, I was on the phone with a friend of mine, an audio engineer at MCA-Universal Studios. He related a story about a recording project, wherein they needed to choose, between a very-imaginable large number of microphones, to determine the “correct” mic for the project. This is the first time I’d heard of such a dilemma nor a Neumann mic. He told me that do help the producers’ choice, he would use a pink-noise generator and an oscilloscope! That way they could determine which mic could deliver the output needed for best results. I hope that helps you in your making a list of possible uses for a pink-noise generator. I’m sure that I’ve bought many Neumann mics as a result of my belief in what he told me.
Really interesting and useful video, Tony. For those of us without a spectrum analyser, is there any way of using FFT analysis on a digital scope to calibrate the pink noise generator?
Hi Tony, nice project 👍 again Velleman has some pretty decent kits 🤔 shame you didn't compare this kit with pink noise from DATS V3. I'm already looking forward to practical testing. Nice day 🙂🙂 Tom
Thank you very much for sharing your knowledge, I always learn something from you. You can generate noise (3 types) audio file using Audacity, an open source software.
Hi Tony . I will appreciate if you supply us a simple circuit diagram for producing pink noise from the white noise produced from the "noisy" transistor circuit
One thing strikes me, the human ear won't treat frequencies equal, but I am not convinced that if you roll off at exactly -3db at every octave that it then fit our ears perfectly. That is looking at our ears as machines. We also know that at higher frequencies our ears perception rolls off quickly to zero, depending on the health of them. You cannot tie a strict math relation to that ? But sure indeed, the pink noise sounds much better than the white noise.
Hi Tony. You said, “minus 3 dB attenuation,” but didn’t you really mean (plus) 3 dB of attenuation, or -3 dB of gain? To me, -3 dB of attenuation would be 3 dB of gain (amplification.)
Thank you for the video! 1) Would two of the digital kits - one for the stereo left channel and one for the right - make an uncorrelated generator, or would the electronic means which creates the psuedo signal be too close in non-randomness between the two kits? I can understand why starting with two transistor created white noise generators, the two channels would be totally uncorrelated - because no two transistors are the same... I hope I said that well enough to be understood... Cheers.
The digital ones will be uncorrelated, especially if left running for a while, and with clocks that are not set to the same frequency. that way clock drift will move them out of phase with each other.
If you used two of the kits from this video, they would generate an uncorrelated stereo noise signal, since the reference oscillators are running independently from one another and are not phase or frequency locked to one another. Thanks for the comment!
Correct. As long as the signals are both sinusoidal, then the RMS value of either signal will be .707 of the peak voltage, regardless of the frequency. Since peak voltage is 1/2 peak-to-peak, then RMS would be .5 * .707 = 0.3535 volts. Calculating RMS of a complex waveform is a bit more complicated than the basic sine wave, but essentially it's the same idea.
Don't be making any brown noise generator only if you want to upset somebody😂 how did they issue a color to the noise and why was that? and why those colors is it something to do with light frequencys?
I’m all in on the topic of this video. I hate to depend on a phone app or software on my laptop to do basic tests, unless I need a printout. I just think I could really use a pink noise generator along with my old analog RadioShack Sound Level Meter to start dialing in my speakers, adjusting my room EQ device, setting sound levels for AB testing of speakers, amps, sources, etc. It just seems like a very useful device for me right now.
I once saw an article about a better analog noise generator. It may have been an application note by B & K (Bruel & Kjaer) or somebody else. But the core idea was that the single transistor noise source provides more unpleasant noise than necessary. You should utilize two transistors, one avalanching on positive voltage and the other one on negative voltage. Then you add the two individual noises and get a balanced noise. I think that the experience is like having all (odd and even) harmonics in a distorted signal, rather than mostly even harmonics..But I may already remember wrong. Anyway, the summing of the two sources requires one or two DC blocking capacitors and two identical resistors feeding the two signals to the inverting input of an op-amp and the resulting “better” noise is available at the op-amp output.. This is of course still white noise. BUT, another noise source I have once seen used a CMOS op-amp CA3130 (originally from RCA) at a reduced power rail voltage that maximized the noise - and surprise, it produced PINK noise without further filtering!
Finally, James G. Holbrook in his book Laplace Transforms for Electronic Engineers - Second edition 1966, Library of Congress Catalog Card 59-12607 - has a thorough treatise of synthesizing the white to pink noise filter, starting around page 254. He also has other applications for the synthesized circuit. Just for anybody (possibly?) curious.
Thank goodness we can't hear Brown noise over the internet! 😊
You can hear them, as long as you don't edit them out. Thankfully, you can't smell them over the internet ☺
HELLO TONY, ....in the past we used interstation noise on the FM band because we had no pink noise generator...
I used the FM noise to calibrate recording with a three-head AIWA M700 and AKAI 646 tape deck
Awesome, I would like you to demo the scope some more please and I have used noise to measure frequency response and it's quite intuitive it seems obvious when you get into it. Good stuff........cheers!
I have a Panasonic white, pink and brown noise generator from the 1980's. I think it was actually made by Matsushita. All of the print on it is in Japanese and I had to get a friend translate it for me. Got it on eBay Japan which I might add is a great place to pick up vintage Japanese electronics and test equipment.
matsushita is panasonic's parent company so yes, it was made by matsushita. :)
@@josephlalock8378 LOL, I realize that. Point was it was made in house and not by another company for them. I have some analog meters labeled Matsushita and some Panasonic. Exact same meter but different silk screened faceplate.
Noise /hiss (( even tape hiss) tells a lot about what and how a component , a speaker or a system will sound .
As soon as I clicked the ad that played was some political mayor peet guy propaganda and it struck as so funny the gulp of coffee spewed out with a large belly laugh - thanks utoob digital commedy algo 🤣
Noise is what my parents call the music I listen to.
15:32 - I'd try a BR-549, Tony! :)
Hi Tony,
I have an interest in your stabilizer device that demands a story about a possible use.
In the 80’s, I was on the phone with a friend of mine, an audio engineer at MCA-Universal Studios. He related a story about a recording project, wherein they needed to choose, between a very-imaginable large number of microphones, to determine the “correct” mic for the project. This is the first time I’d heard of such a dilemma nor a Neumann mic.
He told me that do help the producers’ choice, he would use a pink-noise generator and an oscilloscope! That way they could determine which mic could deliver the output needed for best results.
I hope that helps you in your making a list of possible uses for a pink-noise generator. I’m sure that I’ve bought many Neumann mics as a result of my belief in what he told me.
Really interesting and useful video, Tony. For those of us without a spectrum analyser, is there any way of using FFT analysis on a digital scope to calibrate the pink noise generator?
Hi Tony, nice project 👍 again Velleman has some pretty decent kits 🤔 shame you didn't compare this kit with pink noise from DATS V3. I'm already looking forward to practical testing.
Nice day 🙂🙂 Tom
I'll have to do that sometime. Thanks for the suggestion!
Thank you very much for sharing your knowledge, I always learn something from you. You can generate noise (3 types) audio file using Audacity, an open source software.
I actually have several files I use (including an uncorrelated pink noise file) that I generated in Audacity. ;)
Tony maybe you should switch to the camera from a Matrix MI10 printer?
Hi Tony . I will appreciate if you supply us a simple circuit diagram for producing pink noise from the white noise produced from the "noisy" transistor circuit
One thing strikes me, the human ear won't treat frequencies equal, but I am not convinced that if you roll off at exactly -3db at every octave that it then fit our ears perfectly. That is looking at our ears as machines. We also know that at higher frequencies our ears perception rolls off quickly to zero, depending on the health of them. You cannot tie a strict math relation to that ?
But sure indeed, the pink noise sounds much better than the white noise.
your results may vary...same with color
A lot of zener diodes are also noisy, though it really is variable on them as well.
Hi Tony. You said, “minus 3 dB attenuation,” but didn’t you really mean (plus) 3 dB of attenuation, or -3 dB of gain? To me, -3 dB of attenuation would be 3 dB of gain (amplification.)
I hate to speak for someone but I am certain that is what he intended to convey
Thank you for the video! 1) Would two of the digital kits - one for the stereo left channel and one for the right - make an uncorrelated generator, or would the electronic means which creates the psuedo signal be too close in non-randomness between the two kits? I can understand why starting with two transistor created white noise generators, the two channels would be totally uncorrelated - because no two transistors are the same... I hope I said that well enough to be understood... Cheers.
The digital ones will be uncorrelated, especially if left running for a while, and with clocks that are not set to the same frequency. that way clock drift will move them out of phase with each other.
@@SeanBZA Thanks! Great information. I appreciate it.
If you used two of the kits from this video, they would generate an uncorrelated stereo noise signal, since the reference oscillators are running independently from one another and are not phase or frequency locked to one another. Thanks for the comment!
@t1d100 Tap off the first CD4006 and use another filter - the sequence will be roughly 250,000x ahead/behind (effectively uncorrelated)
@@jim9930 Clever! Thanks!
Pink noise is used with graphic equalizers and microphone to set-up a listening room.
So if I understand this correctly (I probably don't), a 1 KHz / 1V peak-to-peak signal has the same energy as a 10Khz / 1V peak-to-peak signal?
Correct. As long as the signals are both sinusoidal, then the RMS value of either signal will be .707 of the peak voltage, regardless of the frequency. Since peak voltage is 1/2 peak-to-peak, then RMS would be .5 * .707 = 0.3535 volts. Calculating RMS of a complex waveform is a bit more complicated than the basic sine wave, but essentially it's the same idea.
2N3904 is NPN, 2N3906 is PNP.
If you take white noise and remove the pink noise from it, what are you left with then?
Green noise?
its gonna be blue noise
good vid thank you
Don't be making any brown noise generator only if you want to upset somebody😂
how did they issue a color to the noise and why was that? and why those colors is it something to do with light frequencys?