Huh... simplest possible realization of delta-sigma ADC basically, neat. I once tried doing a delta-sigma ADC on a breadboard, but I overdid it with a separate comparator and an active integrator circuit with an op-amp. It never struck me to just use a passive RC circuit as the integrator and flip-flop input threshold as the comparator. I like it :)
@Jeri Ellsworth Instead of directly running the Q output to the audio, what if you ran it through an array of 128 bit shift registers, say the CD4517BE. At the end of the array of CD4517s then take the audio and run it through the low pass, but mix the original audio back with the delayed signal of the 4517s. You would clock the 4517s with the same clock, but probably around 44.1khz Would this not make a crude digital delay? Once my other project is done I will experiment with this, as I have 10 CD4517s, it would happen!
Excellent. Interesting how, as the sample rate drops, aliasing effects take hold, and make the output less accurate but rather aesthetically interesting.
I think this is delta sigma ADC. I have worked on delta sigma ADCs. You can say that the D flip-flop is used as “quantiser”. The 10k resistor is essentially summing the negated quantiser output (q-bar) and the input voltage. I.e. it’s doing (vin- quantized_vout). Then the combination of 10k and 0.1 capacitor is making an integrator.(low pass filter) So, is first order delta sigma modulator. If you show the FFT of q output, you should see the noise shaping and it should show a slope of 20db/decade
thanks soooo much Jeri: I've seen specs (in audio equipment) about a 1 bit a/d and always wondered how it worked. I teach and experiment with microcontrollers (and other electronics) so this video is very valuable to me. Thank-you, Mark.
This is used in all audio codec. Iphone for example. The actual bit is function of your oversampling rate. Iphone has 24bit deltasigma codec supplied by cirrus logic.
I haven't sweep it too far, because the distortion depends on the sample frequency and the low pass filters. The designer would need to tweak the values for their application.
Jeri, Very interesting video - I don't know if I have anything to offer to you, but I am an Engineer with a large German test equipment company. Your videos are of interest to myself and my colleagues at work. Please keep up the good work :)
They do use flash converters, but typically only 1 or 2 bits or resolution. The SNR is so low, that using extra bits only samples the noise. I've seen specs like 1-2 bits and 8 Gsps. They they correlate the bit streams to get phase shifts between the antennas.
This video popped up as new on my RUclips subscription. Now, I see that it is several years old. In any case, I enjoyed the short circuit ( your pun, not mine :-) ) demonstration and explanation. Good job. FWIW, study Nyquist to advance to a higher level of understanding. A quick Google search will get you started. I always enjoy your videos.
I read the Wiki on Delta-Sigma Modulation. So its realy NOT PWM as mentioned. Its more like "Pulse Density modulation" or "Pulse Frequency modulation" which makes more sense. still a realy interesting method for sampling and synthesizing signals.
The only problem is is that you have to have some very fast switching power mosfets at a speed of 3GHz for CD quality sound (44100 x 65536). There are noise-shaping and dithering algorithms that can be applied to lower that quite a bit(
I really like the partial intrusion of your face. (You *do* have a very pretty face, Jeri.) Whether you planned the vid that way or not, it's still a catchy way of including the announcer.
Jeri thanks for taking a few minutes to talk with me at NYC Maker Fair. Have you tried using a photo cell other than a pot for the input? It could come up with interesting feedback with music as the input and a stepper circuit on the output with some party lights.
Thanks for the video! But i can't understand, why flip-flop's nQ signal changes sometimes on falling edge and sometimes on rising edge of CLK as shown on your diagram(1:19)?
I wonder how close this is to the 1-bit ADC processor (Direct Stream Digital) that Sony uses for their Super Audio CD. I'll have to find some more information about Sony's processor but I'm sure it won't be as clearly explained as this.
Great to have you back, you frequently seem to post something on what I'm learning in school right now, and please don't Dave Jones up your vids, one is good enough ;)
Good to see you back and cheers for the interesting video. I know my next question is going to be a long shot, but is there a chance us to find out what kind of projects you are working on at Valve?
Quite brilliant. Is it possible to digitize a certain frequency band (let us say 500 Hz up to 10 Khz) with this circuit and/or how critical is the filter at the output when a whole frequency band has to be restored from a digital signal to a sine wave. Does the restore filter have to be adapted for all the parts of the audio range?
I've rewachted the video and I think I get it. There will be a requirement that the signal has an amplitude > 0.7 to guarantee that the toggling would skip. Fluctuations of a lower amplitude could be missed as the toggling might not skip resulting in loss of data?
This is sort of a vague guess, but could one turn a 1 bit coverter into a multiple bits one by iterating the sampling signal into a multi phased clock that would change the value of a single voltage comparator? The duration of the sampling signal iteration would have to be fast but I suppose that way the bit resolution would depend on the speed of the components and not on their number or how small they are. Nice to see a new video btw
Humble opinions: this is not going to be a 74LS series, only some cmos (C, HC, HCT...); this looks a lot like sigma delta, or how it is called on english... There is also adaptive sigma delta for video signals. I do not think like schematics on wiki about it... these are too complicated... book base "Osnovi telekomunikacija" I.S.Stojanovic 1985, pages 594-604 as first in hand. But this simple and working, genious... Best Regards, Goran
Am I correct in understanding that due to the fact that this is 1 bit and the design of the circuit hat this would only allow you to sample and recreate any frequency modulation; any amplitude modulation would be lost? If we wanted to capture any modulation in the amplitude of the frequency it would just be case of setting up n bits with a different reference point?
My first comment on your videos, which I love. Did you move all of your pinball machines? (I have 4 and I think that's a lot) You are the coolest girl. You can weld and fabricate, drive a race car, like pinball, science, things that shoot flames and explosions. I'm very impressed.
How do you do a sine wave in binary? It would have to be hexadecimal. Wish I paid attention when I was being taught the use of these measurement devices.
@jeriellsworth Hi Jeri, I tried to implement your circuit on a PDM raw signal, but have had no luck. Do you have a good way of implementing a Delta-Sigma Modulator for PDM signals? I am very green in audio sampling.. Thanks
Huh... simplest possible realization of delta-sigma ADC basically, neat. I once tried doing a delta-sigma ADC on a breadboard, but I overdid it with a separate comparator and an active integrator circuit with an op-amp. It never struck me to just use a passive RC circuit as the integrator and flip-flop input threshold as the comparator. I like it :)
I've never gotten bored while listening to you. Talk as much as you like!
Your short circuits videos are always interesting. Thanks!
It will sample amplitude also. You can see that it's reconstructing the low points in the sine wave.
@Jeri Ellsworth
Instead of directly running the Q output to the audio, what if you ran it through an array of 128 bit shift registers, say the CD4517BE.
At the end of the array of CD4517s then take the audio and run it through the low pass, but mix the original audio back with the delayed signal of the 4517s.
You would clock the 4517s with the same clock, but probably around 44.1khz
Would this not make a crude digital delay?
Once my other project is done I will experiment with this, as I have 10 CD4517s, it would happen!
Excellent. Interesting how, as the sample rate drops, aliasing effects take hold, and make the output less accurate but rather aesthetically interesting.
I think this is delta sigma ADC.
I have worked on delta sigma ADCs.
You can say that the D flip-flop is used as “quantiser”.
The 10k resistor is essentially summing the negated quantiser output (q-bar) and the input voltage. I.e. it’s doing (vin- quantized_vout). Then the combination of 10k and 0.1 capacitor is making an integrator.(low pass filter)
So, is first order delta sigma modulator.
If you show the FFT of q output, you should see the noise shaping and it should show a slope of 20db/decade
The new place is great. Finally enough room to stretch out a bit.
There is a frequency shift, but it's not linear like a FM transmitter.
This I showed the reconstruction of the signal in the video for the demonstration, but you's feed the q output to a MCU or FPGA.
Congrats on being hired for Valve Software! =D Can't wait to see what you guys come up with and awesome video like always!
A FANTASTIC EXAMPLE OF HIGH AND LOW DEFINITION DIGITAL SOUND!
thanks soooo much Jeri: I've seen specs (in audio equipment) about a 1 bit a/d and always wondered how it worked. I teach and experiment with microcontrollers (and other electronics) so this video is very valuable to me. Thank-you, Mark.
It's a MDO4104-6 and it's the companies. I have an old B&W Tek at home.
It's always nice to see how much fun one can have with parts worth only a couple of cents.
This is used in all audio codec. Iphone for example. The actual bit is function of your oversampling rate. Iphone has 24bit deltasigma codec supplied by cirrus logic.
I like the lower sample rate. Reminds me of the 8bit days.
I haven't sweep it too far, because the distortion depends on the sample frequency and the low pass filters. The designer would need to tweak the values for their application.
Thanks Jeri. I like the way your explain how components and circuits work.
Yep. It's pumping down right now.
Brilliant advances you have made Jeri Ellsworth . Great vid !
This is a good demonstration for the elimination of "key clicks" using morse code (CW) on home-brew ham radio equipment.
Well I just learned a ton. Thanks! I hope you like your new digs. Sounds like you have lots of room.
Jeri, Very interesting video - I don't know if I have anything to offer to you, but I am an Engineer with a large German test equipment company. Your videos are of interest to myself and my colleagues at work. Please keep up the good work :)
Great seeing a new video! Don't let the haters hate on the uploading of old fmcg vids, I've enjoyed going back through them.
I've seen one bit ADCs before, but always with an explicit voltage comparator. That's slick.
Interesting, it looks like the simplest model of Delta Sigma ADC modulator.
Nice! Very high sample rate, 1-bit ADCs are commonly used in astronomical radio interferometry. This gives me some ideas.
They do use flash converters, but typically only 1 or 2 bits or resolution. The SNR is so low, that using extra bits only samples the noise. I've seen specs like 1-2 bits and 8 Gsps. They they correlate the bit streams to get phase shifts between the antennas.
@Zappyguy111 it really stands out when the sample rate is lowered.
It's a nice unit.
Likewise.
I haven't tried anything, but music, which worked well.
Thanks. We have cool things in the works.
This one wasn't so short. I originally tried to make them 3 minutes long.
I think a guitar effect box would be the killer app for this. :)
This video popped up as new on my RUclips subscription. Now, I see that it is several years old. In any case, I enjoyed the short circuit ( your pun, not mine :-) ) demonstration and explanation. Good job. FWIW, study Nyquist to advance to a higher level of understanding. A quick Google search will get you started. I always enjoy your videos.
I'm sure using a comparator set 50% the rails would yield better results. Might be worth a test.
That casual "electron microscope in the garage" line never fails to make me laugh.
jerri ellsworthe: has an electron microscope in her garage, is more interested in teaching us about circuits.
you're awesome!
I finished the cage and then the person I built it for ran out of money and sold it.
If you zoom in on the Q output, do you see any occasional metastability events?
Nice demo of a delta sigma ADC
I read the Wiki on Delta-Sigma Modulation. So its realy NOT PWM as mentioned. Its more like "Pulse Density modulation" or "Pulse Frequency modulation" which makes more sense. still a realy interesting method for sampling and synthesizing signals.
The only problem is is that you have to have some very fast switching power mosfets at a speed of 3GHz for CD quality sound (44100 x 65536). There are noise-shaping and dithering algorithms that can be applied to lower that quite a bit(
I think you should have shown an fft for the final output in place of or in addition to the waveform output.
No problem.
Thanks.
wow, almost sounded like an Oboe there...circuitgirl is becoming synthgirl. Love your videos...your amazing.
Sounds like it also has the makings of a nice guitar effects box (though not nearly as grandiose a use case as astronomical radio interferometry).
Wow. You are like a celebrity to me. I hope I meet you someday. Hope you brought your umbrella!
Hmm, on second thought, no one should ignore the benefits of editing video.
I really like the partial intrusion of your face. (You *do* have a very pretty face, Jeri.) Whether you planned the vid that way or not, it's still a catchy way of including the announcer.
Cool. Wonder why they choose that over flash converters?
We have a new hardware R&D dept.
Interesting circuit and very simple to use.
sounds like many good videos to come...
thanks a lot
Jeri thanks for taking a few minutes to talk with me at NYC Maker Fair. Have you tried using a photo cell other than a pot for the input? It could come up with interesting feedback with music as the input and a stepper circuit on the output with some party lights.
This is really neat- I'm gonna have to go try it later
I moved most of them up. I still have a few in PDX that need to be moved.
Nice video. Looks like this would have some music synthesis applications!
Reminds me of a class-D amp. Nice!
That in itself is awesomeness. None the less I simply admire her. She's intelligent, beautiful AND (thanks to you) knows what she wants. ;)
Thanks for the video! But i can't understand, why flip-flop's nQ signal changes sometimes on falling edge and sometimes on rising edge of CLK as shown on your diagram(1:19)?
Ow man. That was one of your cooler projects. Well counting the ones i seen on your channel anyway :)
I wonder how close this is to the 1-bit ADC processor (Direct Stream Digital) that Sony uses for their Super Audio CD. I'll have to find some more information about Sony's processor but I'm sure it won't be as clearly explained as this.
Cool, I just watched that FMSG episode and was wondering what he was talking about.
Great to have you back, you frequently seem to post something on what I'm learning in school right now, and please don't Dave Jones up your vids, one is good enough ;)
Yep. It drops of fast when the sample rate gets low.
it wasn't a serious question, merely trying to seed the concept of electric cars in Jeri's mind : )
Good to see you back and cheers for the interesting video. I know my next question is going to be a long shot, but is there a chance us to find out what kind of projects you are working on at Valve?
That is a possible application.
It could be use to control the speed of a DC motor but the response would very un-linear. Try breadboarding it and see what happens?
Quite brilliant. Is it possible to digitize a certain frequency band (let us say 500 Hz up to 10 Khz) with this circuit and/or how critical is the filter at the output when a whole frequency band has to be restored from a digital signal to a sine wave. Does the restore filter have to be adapted for all the parts of the audio range?
I've rewachted the video and I think I get it. There will be a requirement that the signal has an amplitude > 0.7 to guarantee that the toggling would skip. Fluctuations of a lower amplitude could be missed as the toggling might not skip resulting in loss of data?
Nifty minimalist circuit! Tell us about the electron microscope, please. Playing with one of those beasties was a childhood dream.
I was thinking today that a window comparator would make a pretty simple one bit a to d converter.
So you made a class D unity gain amplifier? A class D buffer? :D
Awesome as always Jeri, keep it up !
This is sort of a vague guess, but could one turn a 1 bit coverter into a multiple bits one by iterating the sampling signal into a multi phased clock that would change the value of a single voltage comparator?
The duration of the sampling signal iteration would have to be fast but I suppose that way the bit resolution would depend on the speed of the components and not on their number or how small they are.
Nice to see a new video btw
Simple and subtle sigma-delta, I like it! Did you sweep it? What is it's frequency response like?
What is the amplitude of the input sine wave?
Humble opinions: this is not going to be a 74LS series, only some cmos (C, HC, HCT...); this looks a lot like sigma delta, or how it is called on english... There is also adaptive sigma delta for video signals. I do not think like schematics on wiki about it... these are too complicated... book base "Osnovi telekomunikacija" I.S.Stojanovic 1985, pages 594-604 as first in hand.
But this simple and working, genious...
Best Regards,
Goran
congrats on your job with valve!
Am I correct in understanding that due to the fact that this is 1 bit and the design of the circuit hat this would only allow you to sample and recreate any frequency modulation; any amplitude modulation would be lost? If we wanted to capture any modulation in the amplitude of the frequency it would just be case of setting up n bits with a different reference point?
Missed you ♡
Nice o-scope you got there. What model is it and is that yours or the company's?
Best of luck on your new job!
Seems almost like a delta-sigma but incredibly simple
Oh wow! You've just invented DSD audio!
My first comment on your videos, which I love. Did you move all of your pinball machines? (I have 4 and I think that's a lot) You are the coolest girl. You can weld and fabricate, drive a race car, like pinball, science, things that shoot flames and explosions. I'm very impressed.
This is simplistically cool!
How do you do a sine wave in binary? It would have to be hexadecimal. Wish I paid attention when I was being taught the use of these measurement devices.
Great explanation, btw what scope do you have in that video?
Check out, "The Signal Path" #32
Is there a modification to remove the requirement of an external clock signal and have it run/compare as fast as possible?
great video as usual!
you said your working for valve software, how did change from hardware design to a more game oriented job if its okay to ask ?
@jeriellsworth Hi Jeri, I tried to implement your circuit on a PDM raw signal, but have had no luck. Do you have a good way of implementing a Delta-Sigma Modulator for PDM signals? I am very green in audio sampling.. Thanks
thanks for the CLEAR explanation of this underdog circuit. also congrats with the new job! did you say you had an electron microscope?!
Thanks! Very easy to follow you.
Watch out you will be adding opamps to your next design.
Whats abaout frequency Guzheng instrumen music up down?because Device do not 4(12356 .....),Thanks info video