The reason the spectrum changed when you adjusted time/div I believe is the cycles it shows on screen are the number of cycles it samples, so more is better-more detailed.
The guitar amp tone stack is passive so it's very interactive. If you drop the mid-range all the way down you should get a much better reading on the Bass response. Nice video
Excellent video, thanks for posting this! Love the practical review and application of the FFT functionality of this (or any) scope. Would love to see the techniques you show here put to real life practice repairing a tube amp or similar. Will look through other videos on your channel - this may already be there and I just haven't found it yet. Anyway, thanks!
The greater the number of points in the sample, the greater the precision of the signal in the frequency domain. That is why the FFT aspect changes when you adjust the number of points in the sample.
Thanks for the tip. I just discovered a program called REW that does a great job of frequency response characterization. It's free but you should probably use a USB audio I/O board. The program is written for testing the frequency response in rooms but works great stereos. It even does a good job with THD.
you can also make it less laggy / delayed by lowering the acquisition memory, otherwise it has to run trough all 7 or 14 million measurements every frame
It seems to me that the FFT demo for these audio frequency ranges was completely unlike what one would expect. You would think that cranking the bass or treble control would’ve been immediately reflected in the white noise demo as a quite obvious shelf within the FFT plot, but this totally was not the case. There were must be some underlying reason why the FFT was fairly worthless when used in this way, it is unfortunate that was not determined in this demo. The demo as shown kind of shows that using the FFT at these frequency ranges is useless, no?
Another interesting use, is analyse the tapping of say a wine glass, then play that same frequency back through a high power amp to try and explde the glass, I believe you might have to resonate it first, then shift the phase, thats my theory anyway.
For audio distortion measurement I take a USB Sound interface and the software REW. There you get THD directly on the screen. Much better my Rigol scope can do.
I've found it to be impossible to set FFT for audio frequencies (DC-40kHz) if You want to get any readable information. It is quite pity as device is very powerful and could partly replace very expensive audio analyzers for measuring freq response, THD and noise, but resolution is simply to low at that (low) range. I'm hoping for a new firmware with refactored FFT: 1. Range setting instead of center freq. 2. Logarithmic horizontal scale. 3. FFT for the difference between CH1 and CH2 (to measure balanced line signal with canceled line noise). This would make SDS1202X-E simply the best device on the market for audio engineers. Also I agree with Rob - turning Horizontal resolution knob should not affect what You see on FFT. I can see the point they did this from development perspective, but it absolutely does not make sense for the user.
Around the 5:00 mark when you’re showing the FFT of the sine wave, Next time try it with a Hanning or a Blackman data window setting. (not sure what the scope options are) The window setting used in the video was “rectangular”. This is not ideal for the specific signal you were looking at. This would have reduced the spectral “spread” of energy coming down from the peaks (looks like a tent pole poking up thru a fabric roof) and made the discernment between fundamental and harmonics more apparent, as well as showed the noise floor of the scope (or DUT, but probably the scope)
You don't need to set Hz/div. even to 1kHz for guitar amp. - all magic is happening in between about 60 and 1000 Hz, and because 880Hz is already fifth fret of 1st string and guitar amp frequency response should not be any wider than few KHz. So, you will get much better information if you set Hz/div to something like 250-500, in this case screen will give you information from 0 to 2.5-5KHz, this is enough. P.S I am lucky owner of SDS1202X-E :)
It would also be helpful to capture more of the signal, you would get much more detail on the FFT. Try setting the horizontal scale to about 500ms. And as you said, setting a lower center frequency is also a good choice. Also a fellow SDS1202X-E user :)
You can turn it off, when engages roll mode, just press the roll button on the scope. It will take a second or two to gather the data, but it will display the FFT without a problem.
Aleksandar Todorovic Hmm, I will try this at home, but I was sure that pressing roll button will return to 20ms/div. This is strange, since we have same scopes
I use it on log most of the time except when I was trying to see the frequency response using white noise. The non log seems better for seeing where the response drops off.
I know this is old but maybe it will help someone. My trace stops at 500MHz the scale goes higher but I think that's the limit. The divisions can go down to 391kHz and up to 500Mhz. Then change horizontal and divisions can go down to 1hz.
The noise floor of a general purpose oscilloscope FFT is too high for any audio analysis. You want a proper audio analyzer equipment, or at least a decent sound card or USB audio interface with low enough residual THD and high dynamic range, so you can capture what your amplifier is doing. I find the cheapest is to use a sound card with RightMark audio analyzer software.
Most of the time I just connect to the positive speaker wire. It can get pretty loud so the speaker can be replaced with a high wattage 8 ohm resistor for most tests.
It's a tough call. I liked the screen layout and the speed of the Siglent but I had to give up the extra channels of the RIgol. Good luck trying to decide!
@@GenerationXerography the 4 channel scopes have that auxiliary connector for the AWG and logic analyzer. without the awg, you cant do bode plotting of course.
I got it for testing a 130w guitar amp. I can't remember what it is rated at but it does get hot when testing 100w and over stuff. I've always appreciated its 'overbuilt' look!
Even tempting idea of using this one for audio analysis please do not forget (and that goes for most DSO's in that price range and even more expensive ones) that it only employs an 8-bit ADC. That together with a typical 3-4% level accuracy does not give you much choice in serious audio work. Good for quick check. Figure that an 8-bit ADC is only able to resolve 4096 different amplitude levels which is really not very much. At least a 12-bit or 16-bit ADC would be required to take it to another level. Plus you'd really need at least 0.1% level accuracy. You're then hitting some serious price issues. However for quick checking can be done. Nonetheless I like that Siglent SDS 1000X-E series. For other reasons though (Decoding, long memory etc....)
I would normally use an analog scope for audio work, but I don't see the problem with an 8 bit dac. An oscilloscope has a fancy frontend that lets you "zoom in" on the signal with voltage dividers and offsets, etc, giving you more resolution on a certain part of the wave. I've never really had a problem with 8 bit dacs.
@@autogolazzojr7950 I agree basically. But don't forget that the FFT derives its amplitude resolution from a given signal in the time domain. What isn't there (or let's say interpolated data) might lead to less accurate data in the frequency domain. Plus mind you the Siglent SDS 1kX-E or X series are slow in FFT, really slow. Can't have all for the good price I guess. One only has to accept a few trade-off s and consider things not working the same way like a higher class DSO......
Thanks for the video. My interests are also audio amplifiers, so this is really helpful.
Just bought this scope and received it yesterday, I've been poking around with the PWM pins in Arduino and some 555 oscillator circuits.
The reason the spectrum changed when you adjusted time/div I believe is the cycles it shows on screen are the number of cycles it samples, so more is better-more detailed.
The guitar amp tone stack is passive so it's very interactive. If you drop the mid-range all the way down you should get a much better reading on the Bass response. Nice video
Excellent video, thanks for posting this! Love the practical review and application of the FFT functionality of this (or any) scope. Would love to see the techniques you show here put to real life practice repairing a tube amp or similar. Will look through other videos on your channel - this may already be there and I just haven't found it yet. Anyway, thanks!
The greater the number of points in the sample, the greater the precision of the signal in the frequency domain. That is why the FFT aspect changes when you adjust the number of points in the sample.
Thanks for the tip. I just discovered a program called REW that does a great job of frequency response characterization. It's free but you should probably use a USB audio I/O board. The program is written for testing the frequency response in rooms but works great stereos. It even does a good job with THD.
you can also make it less laggy / delayed by lowering the acquisition memory, otherwise it has to run trough all 7 or 14 million measurements every frame
Hmm, interesting. Thanks for the tip!
It seems to me that the FFT demo for these audio frequency ranges was completely unlike what one would expect. You would think that cranking the bass or treble control would’ve been immediately reflected in the white noise demo as a quite obvious shelf within the FFT plot, but this totally was not the case. There were must be some underlying reason why the FFT was fairly worthless when used in this way, it is unfortunate that was not determined in this demo. The demo as shown kind of shows that using the FFT at these frequency ranges is useless, no?
Another interesting use, is analyse the tapping of say a wine glass, then play that same frequency back through a high power amp to try and explde the glass, I believe you might have to resonate it first, then shift the phase, thats my theory anyway.
Nice video and very helpful!!!
Thanks!
Very good video❤, 🇧🇷😉👏👏👏👏
Thank you!
For audio distortion measurement I take a USB Sound interface and the software REW. There you get THD directly on the screen. Much better my Rigol scope can do.
Rew is a really cool piece of software. Very powerful
I've found it to be impossible to set FFT for audio frequencies (DC-40kHz) if You want to get any readable information. It is quite pity as device is very powerful and could partly replace very expensive audio analyzers for measuring freq response, THD and noise, but resolution is simply to low at that (low) range.
I'm hoping for a new firmware with refactored FFT:
1. Range setting instead of center freq.
2. Logarithmic horizontal scale.
3. FFT for the difference between CH1 and CH2 (to measure balanced line signal with canceled line noise).
This would make SDS1202X-E simply the best device on the market for audio engineers.
Also I agree with Rob - turning Horizontal resolution knob should not affect what You see on FFT. I can see the point they did this from development perspective, but it absolutely does not make sense for the user.
For 25000 and 50000 Hz - everything ok.
Around the 5:00 mark when you’re showing the FFT of the sine wave, Next time try it with a Hanning or a Blackman data window setting. (not sure what the scope options are) The window setting used in the video was “rectangular”. This is not ideal for the specific signal you were looking at.
This would have reduced the spectral “spread” of energy coming down from the peaks (looks like a tent pole poking up thru a fabric roof) and made the discernment between fundamental and harmonics more apparent, as well as showed the noise floor of the scope (or DUT, but probably the scope)
Nick, thanks for the info! I learn so much by sharing what I learn.
The repeated pauses as it's doing the maths does my head in. Needs a faster refresh.
Thanks for info.
You don't need to set Hz/div. even to 1kHz for guitar amp. - all magic is happening in between about 60 and 1000 Hz, and because 880Hz is already fifth fret of 1st string and guitar amp frequency response should not be any wider than few KHz. So, you will get much better information if you set Hz/div to something like 250-500, in this case screen will give you information from 0 to 2.5-5KHz, this is enough.
P.S I am lucky owner of SDS1202X-E :)
It would also be helpful to capture more of the signal, you would get much more detail on the FFT. Try setting the horizontal scale to about 500ms. And as you said, setting a lower center frequency is also a good choice. Also a fellow SDS1202X-E user :)
Absolutely true, but after 20ms/div scope will switch to roll mode, and all math functions is unavailable in this mode, so maximum is 20ms/div
You can turn it off, when engages roll mode, just press the roll button on the scope. It will take a second or two to gather the data, but it will display the FFT without a problem.
Aleksandar Todorovic Hmm, I will try this at home, but I was sure that pressing roll button will return to 20ms/div. This is strange, since we have same scopes
Гриша Бецан It works perfecly fine for me
I don't like how the fft display is so small on this scope
Hello. Can you do peak detection in fft to move betweeb harmonics in that siglent scope? Thanks!
Did you forget to set your frequency scale to log?
I use it on log most of the time except when I was trying to see the frequency response using white noise. The non log seems better for seeing where the response drops off.
I got a question that I couldn't found on the net. What is the max frequency you can measure with the fft option of this scope? Thanks
More than 200MHz.
I know this is old but maybe it will help someone.
My trace stops at 500MHz the scale goes higher but I think that's the limit.
The divisions can go down to 391kHz and up to 500Mhz.
Then change horizontal and divisions can go down to 1hz.
The noise floor of a general purpose oscilloscope FFT is too high for any audio analysis. You want a proper audio analyzer equipment, or at least a decent sound card or USB audio interface with low enough residual THD and high dynamic range, so you can capture what your amplifier is doing. I find the cheapest is to use a sound card with RightMark audio analyzer software.
Sowould you recommend this scope over the Rigol for audio repair and restoration? Thanks
it's a very popular entry level scope.
pity you didn't rxplain how you connected your probe to the amp - I'm a noobie atapplied electronics thou I had some theory class
Most of the time I just connect to the positive speaker wire. It can get pretty loud so the speaker can be replaced with a high wattage 8 ohm resistor for most tests.
can i use the trig out jack on the back of the scope to connect to a frequency counter?
Hi, quick question, do you prefer this over a Rigol 1054Z? If so, why? Thanks!
It's a tough call. I liked the screen layout and the speed of the Siglent but I had to give up the extra channels of the RIgol. Good luck trying to decide!
I have the same dilemma but I are thinking about, digging a bit deeper in my pocket and then bye the 1204, would you recommend that?
how do you set fft points
What is the difference between sds1202x-e and sds1202x? What is new about the"e"?
la diferencia de los dos modelos es divicion de voltios.
Since you have a Siglent function gen, isn't there a way to make Bode plots with your scope?
Thanks for the tip. I just watched EEVblog which has this video that shows a great technique. ua-cam.com/video/uMH2hGvqhlE/v-deo.html
Ok I just realized it's the Siglent SDS1204XE that has the built-in Bode plot feature.
@@GenerationXerography the 4 channel scopes have that auxiliary connector for the AWG and logic analyzer. without the awg, you cant do bode plotting of course.
LOL, whats the power rating of that massive green resistor? looks like it could shunt a substation! )
I got it for testing a 130w guitar amp. I can't remember what it is rated at but it does get hot when testing 100w and over stuff. I've always appreciated its 'overbuilt' look!
@@RobsFixitShop Definitely oversize, still it looks bad ass.
how noise signal on screen delay
Is anyone familiar with defective units with BA in the serial number?
🇧🇷😉👍 subscribed
Thanks!
bro add tutorial
Why is the FFT refresh rate so slow ? It is worthless for any realtime signal.
It was disappointing to me
Even tempting idea of using this one for audio analysis please do not forget (and that goes for most DSO's in that price range and even more expensive ones)
that it only employs an 8-bit ADC. That together with a typical 3-4% level accuracy does not give you much choice in serious audio work. Good for quick check.
Figure that an 8-bit ADC is only able to resolve 4096 different amplitude levels which is really not very much. At least a 12-bit or 16-bit ADC would be required to
take it to another level. Plus you'd really need at least 0.1% level accuracy. You're then hitting some serious price issues. However for quick checking can be done.
Nonetheless I like that Siglent SDS 1000X-E series. For other reasons though (Decoding, long memory etc....)
I would normally use an analog scope for audio work, but I don't see the problem with an 8 bit dac. An oscilloscope has a fancy frontend that lets you "zoom in" on the signal with voltage dividers and offsets, etc, giving you more resolution on a certain part of the wave. I've never really had a problem with 8 bit dacs.
@@autogolazzojr7950 I agree basically. But don't forget that the FFT derives its amplitude resolution from a given signal in the time domain. What isn't there (or let's say interpolated data) might lead to less accurate data in the frequency domain. Plus mind you the Siglent SDS 1kX-E or X series are slow in FFT, really slow.
Can't have all for the good price I guess. One only has to accept a few trade-off s and consider things not working the same way like a higher class DSO......
An 8 bit number can only hold 0-255, so only 256 'levels', 4096 would be 12 bits.
incoherent unclear story