Do you need a 12-bit scope? - Page 1
Forum section: electronics / testgear

author: slugrustle
author_rank: Frequent Contributor
timestamp: August 22, 2025, 01:47:48 am
content: Do you need a 12-bit scope? Is there anything you can accomplish with a 12-bit that you can't accomplish with an 8-bit?Between ability to change vertical scales, offset traces, and on some occasions use a 1x probe or low noise amplifier, I find I can do most things just fine with an 8-bit scope (Siglent SDS2504X+). What am I missing?As a caveat, I use a Cleverscope CS320A-FRA (14-bit) for frequency response analysis / bode plot. The integrated isolated signal generator and software make it really nice for this application. I use a Picoscope 4262 (16-bit, 8.5µV RMS noise floor) for noise spectrum testing. I feel like a generic 12-bit scope wouldn't be as good at these more niche applications.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 22, 2025, 01:55:04 am
content: It sounds like you're pretty well covered. The SDS2504X+ is a great scope. I had that and went to the SDS2504X HD. There's not much of a difference looking at 10-bit on the SDS2504X+ vs 12-bit on the HD model. For me anyway.Other areas were more interesting. Like overall system speed/responsiveness, additional math channels, etc. I wouldn't recommend switching just for the extra couple of bits. That metal handle though; that's something special.

author: David Hess
author_rank: Super Contributor
timestamp: August 22, 2025, 02:41:18 am
content: 12-bits will be useful for higher dynamic range FFT measurements. 12-bits by itself will not yield lower noise measurements, lower distortion, or faster settling times because these are already limited by the analog design of the front end.

author: Performa01
author_rank: Super Contributor
timestamp: August 22, 2025, 10:46:02 am
content: Quote from: slugrustle on August 22, 2025, 01:47:48 amThe Pico 4262 is a unique instrument for the frequency range from 0 to 5 MHz. Everyone who needs analysis capabilities in that frequency range barely has an (affordable) alternative.12 bits are really useful for the inspection of small details in large signals, as demonstrated in the 2nd part of the linked post (Vertical Zoom Demo):https://www.eevblog.com/forum/testgear/sds800x-hd-review-demonstration-thread/msg5293744/#msg5293744Let’s calculate that. A 12-bit SDS800X HD uses a total of 3840 visible LSB on a screen that is 600 pixels high and less than 500 of them can be used for waveform display. That means you can zoom in vertically almost 8 times and still looking at the original sample data.An 8-bit SDS2000X Plus uses a total of 240 visible LSB on a screen that is 600 pixels high and less than 500 of them can be used for waveform display. That means that resolution is insufficient even without zoom. One could say you can zoom in vertically less than 0.5 times…The difference between 0.5x and 8x is 16x, which unsurprisingly corresponds to the difference in ADC resolution.There are other areas, where one could expect an advantage because of the 12 bits:1. FFT.There is no real advantage for practical use cases. FFT dynamic range is >100 dB for a properly implemented 1 Mpts FFT regardless of the ADC resolution. See a demonstration here for the SDS800X HD, 3rd part of the post (FFT Dynamic range):https://www.eevblog.com/forum/testgear/sds800x-hd-review-demonstration-thread/msg5293765/#msg5293765Here you get even a comparison of a 12-bit SDS2504X HD to the old 8-bit SDS1104X-E:https://www.eevblog.com/forum/testgear/siglent-sds1104x-e-in-depth-review/msg5195079/#msg5195079This article also describes the only (made up) use case, where 12 bits still work where 8 bits would fail, but this is not a real use case, because no one in their right mind would try to measure an isolated signal in the realm of microvolts at a vertical sensitivity of 100 mV/div. And at 1 mV/div, it works even on an 8-bit oscilloscope.2. Bode PlotOne would expect a better dynamic range for the Bode Plot, and in some corner cases there might actually be a small advantage. But just like with the FFT, a properly implemented Bode Plot with a tracking BP filter at the receiver end will give you identical results, regardless of the ADC resolution, as long as AGC (Automatic Gain Control) is active. It might be different if fixed gain is chosen, but fixed gain cripples the dynamic range and there is usually no need for that.3. Vertical MeasurementsOf course, the accuracy of vertical measurements is greatly enhanced. Even the DC-accuracy is better. No wonder, 12 bits would be enough for a 3 ½ digit DMM. But as soon as the measurement statistics is enabled and the Mean value is used instead of the current one, the advantage of the 12 bits suddenly isn’t huge anymore.

author: hpw
author_rank: Frequent Contributor
timestamp: August 24, 2025, 09:44:46 am
content: Quote from: David Hess on August 22, 2025, 02:41:18 amYes, as I like the HD3 Keysight as 14 bit & 50uV by data sheetthis means about half or any 6dB better in noise performance.Liked to rent such gear but this is impossible.As the owners (purchased of free gift from Keysight) of such instrument are currently not willing or able to provide such measurements.Keysight, now even a video for higher bits showed, but without any comprehensive measurements. Also the FFT in the datasheet as maximal 64k FFT noted, lets me think as a limitation. The spurs or SFDR not noted and only to guess.My needs are to measure power noise & reference noises (1/f noise, 10Hz...100MHz spurs & noise) as for ADC & DAC. I currently use a differential LNA using a SDS2K + in 10 bit mode and would like to go any deeper or any better used ADC on the DSO. In addition any cross correlation setup (as on PN gear) would show any 6dB better noise.Higher FFT as 1M would show better noise floor and would show any spurs & SFDR values any better.So waiting for the next 14... bit DSO as after the current 12 bit decade.Hp

author: egonotto
author_rank: Super Contributor
timestamp: August 24, 2025, 12:55:38 pm
content: Hello,@hpw: If you have 50 uVrms noise, that's about 300 uVpp. At 500 uV/div and 14 bits, 300 uVpp is about 1200 pp. At 12 bits, it would still be 300 pp.Even if you only had 2 uVrms noise due to bandwidth limitation, that would still be 48 pp at 14 bits and 12 pp at 12 bits.So what advantage does 14 bits have over 12 bits?Best regardsegonotto

author: Psi
author_rank: Super Contributor
timestamp: August 24, 2025, 01:03:26 pm
content: In general no, 8 bits is fine, but it's nice to have voltages that are not rounded to the nearest 40mV or whatever.

author: mawyatt
author_rank: Super Contributor
timestamp: August 24, 2025, 01:15:09 pm
content: Quote from: hpw on August 24, 2025, 09:44:46 amIf one is after higher DSO resolution, ERES might be of use. This adds a low pass FIR filter and some DSOs use hardware to implement this feature.Similar wants/needs/desires, this is gathering some interest here at "The Labs" and precipitated these discussions.https://www.eevblog.com/forum/projects/https://www.eevblog.com/forum/metrology/lflna-80/https://www.eevblog.com/forum/metrology/diy-low-frenquency-noise-meter/https://www.eevblog.com/forum/metrology/low-cost-magnetic-electrical-shielding-enclosure/Best

author: tggzzz
author_rank: Super Contributor
timestamp: August 24, 2025, 01:26:22 pm
content: Quote from: slugrustle on August 22, 2025, 01:47:48 amFor looking at waveform shape, 8 bits is sufficient for many purposes,providedthat the input waveform does not overload the ADC. Hell's teeth, even a 7bit 20kg boat anchor is sufficient, provided it has the front end bandwidth. I'm sure you know enough to ignore the MS/s marketing specIf you trying to assess the time an opamp/DAC/etc takes to settle to 0.1%, then 12 bit is just about OK but 14-bit would be better.If you are assessing RF parameters then 8-bit is probably not really good enough. The noise floor and intermodulation products are the key parameters to assess.But then arguably anybody using a scope to measure DC voltage or RF properties is living in a state of sinQuote from: Performa01 on August 22, 2025, 10:46:02 amYourexamples show that that 12-bit DSO has more like -70dB dynamic range for real-world use cases: assessing intermodulation products.That kind of effect leads to the first line of my .sig

author: joeqsmith
author_rank: Super Contributor
timestamp: August 24, 2025, 02:08:10 pm
content: Quote from: slugrustle on August 22, 2025, 01:47:48 amSo far, no. Also using amplifiers and other setups when needed. As mentioned, ERES, oversampling....I have played a bit with some of the new Siglent scopes. They update faster and have a lower noise floor. They may also be more reliable than my aging scope (although, after replacing the data acquisition board it's been fine). The downside, they are missing some key features that I use. Having to port various software to a new platform.Staying with 8-bits until my scope dies, or something comes out that looks like it would be a good fit.

author: hpw
author_rank: Frequent Contributor
timestamp: August 24, 2025, 03:21:54 pm
content: The REAL bits also depends on the spurs & SFDR.As my 10bit DSO limits to 100MHz too.The gear of interest is an 24/32 bit ADC & DAC as in audio range as internal 10MHz to 100MHz digital MCK clock. Not to forget the data and bit clock with unknown behavior to the power and Vref of those.This means a 100MHz measure BW is a limitation.Currently use ~ 300Mhz differential LNA & boxed & special shielded connections about 25dB gain.This means, a HD3 may provide lower better input amplifier but only 64K FFT.For me it is very clear, to improve my LNA & getting a better DSO for this purposes.May external stream export as with math & calculations as additional cross correlation using 2 indipended adc channels would help to go into lower noise.Hp

author: voltsandjolts
author_rank: Unknown
timestamp: August 24, 2025, 04:05:08 pm
content: QuoteIf you do, I have one for sale within the UKhttps://www.eevblog.com/forum/buysellwanted/fs-uk-rigol-hdo1074-12-bit-4-channel-oscilloscope/

author: enjoi4283
author_rank: Newbie
timestamp: September 12, 2025, 11:20:04 am
content: I work for Lambda Photometrics, the other UK Rigol supplier.If you would like to evaluate some of the new Rigol 12-Bit scopes, I would be happy to loan you a demo system to complete some tests.Feel free to drop me a PM!https://www.lambdaphoto.co.uk/test-instrumentation/test-measurement/digital-oscilloscopes.htmlAnthonyLambda Photometrics

author: chilternview
author_rank: Frequent Contributor
timestamp: September 17, 2025, 10:34:04 am
content: Quote from: hpw on August 24, 2025, 03:21:54 pmYou can go up to 32Mpts FFT on a HD3.

author: paulca
author_rank: Super Contributor
timestamp: September 17, 2025, 11:45:34 am
content: I tried to explain to audiophiles what "zoom/gain" and "offset" do in regards resolution of a 10bit scope compared to a 16 bit sampler.It didn't go well.Granted simultaneous access to the full dynamic range... can't do.

author: bson
author_rank: Unknown
timestamp: September 17, 2025, 10:12:26 pm
content: Quote from: David Hess on August 22, 2025, 02:41:18 amIt gives youfasterFFTs for a given desired precision since they can be smaller. 8-bit samples require 64x as many, compared to 14-bit, for the same resulting precision. (And then you have to reduce the number of bins, but the visualization will do that automatically.)

author: hpw
author_rank: Frequent Contributor
timestamp: September 18, 2025, 06:45:41 am
content: Quote from: chilternview on September 17, 2025, 10:34:04 amReallyAs Your picture shows clearly 3.05kHz FFT Bin Size!This means calculating backwards:Sample Rate = 200.0 MHzNumber of FFT Points = 2^16 (65536)Resolution Frequency / Line = 3.051758 kHz = FFT RBWMeasurement Bandwidth = 0 - 100.0 MHz as the resulting Spectrum BWThis means, it's a simple 64k FFT and32M Sample Record Lengthas indicated or setup.So, the spectrum is 32M / 64k box carded, means, as 512 times in to one spectrum BIN averaged, or peak hold as the Spectrum Detector algo would tell.How the box cared behaves may look at a R&S manual.Just as in the beginning of the HD3 thread one noted, the HD3 have a free space as the spectrum PCB did not went in as not to compete against the more expensive Keysight Spectrum analyzers as may they do not have lower input LNA and 14bit ADC's.

author: hpw
author_rank: Frequent Contributor
timestamp: September 18, 2025, 07:53:19 am
content: Here a simulated 14 bit & 10MHz Sine & Dither spectrum using 64K & 32M FFT.... real ADC chips will show spurs and any PNAs for sure, the 32M FFT noise floor would be any lower

author: chilternview
author_rank: Frequent Contributor
timestamp: September 18, 2025, 11:39:08 am
content: Quote from: hpw on September 18, 2025, 06:45:41 amIt's anything but simpleAs you increase the horizontal capture time, the span decreases for a fixed fft record length. So for example (see images) at 64k as you move to 100us/div (3.2M pts) the max span reduces to 32MHz with bin size of 3.05KHz.If we go to 500us/div (16M pts) and a bin size of 191Hz but with 256k pts the max freq is 25MHz. And going to 20ms/div (80M pts) with bin size 4.77Hz the max freq can be still 40MHz if we increase the fft record length to 16Mpts.Also note the noise floor is reducing as expected from the larger record length.

author: Fixpoint
author_rank: Regular Contributor
timestamp: September 18, 2025, 12:11:51 pm
content: @OP: I think selling 12-bit DSOs to hobbyists is the same psychological marketing stunt like dynamic-range marketing in photography. You only need it in very specific and professional (!) use cases, but people who don't really understand the underlying math think it is imperative that they own the device with the biggest numbers. That's how money is made, but it has nothing to do with the actual job at hand.In short: For hobbyists, bandwidth and sample rate are the important numbers, not bit depth. The common hobbyist cannot do much with 12 bits, except he is a pretty uncommon hobbyist (i.e., knowledgable in setting up low-noise measuring setups and doing uncommon things that really make use of 12 bits, which is rare).

author: 2N3055
author_rank: Super Contributor
timestamp: September 18, 2025, 02:23:10 pm
content: Quote from: Fixpoint on September 18, 2025, 12:11:51 pmYet you are wrong.First thing first 12 bit is better than 8 bit, all other things being equal.Trace is nice and clean, you can zoom in and still see things.12 scopes from Siglent (but all other too) get better DC accuracy too, so you can use built in measurements for general purpose use.While 8 bit scope can also be low noise, 12 bit ones has to be, so they will generally perform well in that regard.12 scopes are generally newer designs so you get better processing power, nicely responsive instrument.They will also usually have better BW than old ones in the same price range.And since new 12 bit scopes come in all price ranges, there is no need to buy new 8 bit scope if you can buy 12 bit for similar money.Does that mean all people should throw away all their 8 bit scopes. No. Most people are happy with what they have and if it does the job for you why change it at all?And dynamic range in photography is more important to compete amateur than to professional that knows how to do proper exposure....And why did you buy 10bit scope instead of 8bit one if it doesn't matter?

author: hpw
author_rank: Frequent Contributor
timestamp: September 18, 2025, 02:31:25 pm
content: Quote from: chilternview on September 18, 2025, 11:39:08 amyes as your pictures showsPic-1 3.05kHz * 64K = 200MHz as 64k FFTPic-11 488Hz * 64k = 32MHz as 64K FFTPic-12 191Hz * 256k = 50MHz as 256k FFTPic-13 4.77Hz * 16M = 80MHz as 16M FFTFor sure the sampling period defines the maximal possible FFT size.Wired is, as the Keysight manual clearly says 64k FFT.One should confirm my 64k vs 32M FFT picture using this HD3, as the noise floor have to be lower ...

author: Fixpoint
author_rank: Regular Contributor
timestamp: September 18, 2025, 08:19:49 pm
content: Quote from: 2N3055 on September 18, 2025, 02:23:10 pmThe fact that you can "zoom in" and still see smooth lines is *technically* true. But the point is not what you "can do". The point is (a) what you *need to do* to get the job done and (b) whether you can trust what you see.I said the marketing plays the customer with numbers. They say "higher numbers are better". And that is *technically* true, in terms of performance figures. But what they don't say: "Well, the numbers are better, but they won't help you because you don't have the expertise to actually make real use of them". And because most hobbyists don't know what "better" means they think it is also "better" *for them*.For instance, as a hobbyist I might think that I "zoom in", but do I really see higher resolution data or just noise? Does my measurement setup really deliver that kind of resolution? Hm. Most hobbyists can't tell. They just think "I have higher numbers, so I get better results". Additionally, I would suspect that many don't know or understand ENOB.Of course, for an expert, the situation is different. An expert can even make use of a 16-bit scope. So, if you're an expert, by all means have fun with your 128 bit, 50 Ghz, 32 channel, 20 inch scope. Because higher numbers are better ... (but even 32 channels won't save you if you need 33, so you better buy two DSOs, because 2 are always better than 1 ...)I am a hobbyist, and I understand that I cannot make good use of high-spec devices because that requires a lot of specialist expertise.QuoteSurprise, there are more factors for me to consider. I didn't care much for the bit depth. Because it doesn't matter for what I do. I didn't want a "Rigol/Siglent workbench" but wanted at least some equipment from local manufacturers. So, I have R&S, Gossen, and Weller. (But also UNI-T and one of those backbench manufacturers that are often rebranded.)QuoteThese claims have nothing to do with the question. The question was "do you need 12 bit". It was *not* "do you need newer designs", "do you need more processing power", "do you need more responsiveness", "do you need more BW".

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: September 18, 2025, 08:26:37 pm
content: By the logic in this thread I don't need a scope at all, just a 3.5 digit DVM. Heck, ham radio folks built well functioning transmitters and receivers from scratch with less than that. I've used 8-bit digital scopes for many years and never liked them compared to even the worst boat anchor analog. I'm overjoyed with the 12-bit Siglents both at work and at home. And that's all the reason I need.

author: 2N3055
author_rank: Super Contributor
timestamp: September 18, 2025, 08:45:09 pm
content: Quote from: Fixpoint on September 18, 2025, 08:19:49 pmI see you are not only very biased to your choices but also that you never really used one of the new 12 bit scopes. Whoever tried it never wanted to go back. 12 bit scopes (I can speak with authority here about Siglent because I am very familiar with them) show obviously less noise and are more accurate at the same time.Your statement that you cannot use more precise device because you don't have knowledge is quite "unusual".For instance, lower noise and greater resolution and accuracy shows very clearly even on 1V/div using standard 10x probes. No need to look at microvolts to have benefits. Again, it is obvious you never used one. Otherwise you would know what I am talking about.As for what was the original question, I answered that and then made that comment. You conveniently ignored that.Let me be blunt. You are so vehemently fighting for your opinion here, because you cannot afford 12 bit scope by R&S and are horrified that some Siglent can sell you excellent 12bit machine for very little money. That you refused to buy because of those are "inferior devices". That is my opinion. Hence all misdirections and irrelevant claims.I will restate my case.If you have existing scope that is doing the job for you, there is no need to change. Regardless how many bits it has.If you are on the market to purchase new scope there is no reason not to buy 12 bit scope today. Prices are similar and you get more for your money. Unless you are on market for something specific, but in that case you are the expert you are mentioning and you don't need this topic to decide.

author: David Hess
author_rank: Super Contributor
timestamp: September 18, 2025, 09:28:09 pm
content: Quote from: 2N3055 on September 18, 2025, 02:23:10 pmNoise is limited by the high impedance buffer, and is already greater than the least significant bit of an 8-bit digitizer. When current manufacturer's claim "low noise", they mean lower noise an their previous noisy oscilloscopes, not lower noise than a 30+ year old analog or digital storage oscilloscope.Settling time is no better because it was never limited by the digitizer. Transient response is no better because previous 8-bit front ends did not support 8-bit settling and transient response anyway, and they have not improved for 12-bit digitizers. The same thing applies to linearity. (1)If accuracy is better, it is only because they are putting more effort into it. No modern DSO is as accurate as an old analog oscilloscope with slideback capability. This is not important for a time domain instrument like an oscilloscope.So by all means buy a 12-bit DSO if you like, but the performance advantages are less than the increase in resolution suggests. Most of the benefits will come from being a more modern and recent design.There is a case for higher resolution in a low bandwidth design where feedback amplifiers can be used. Pico Technologies makes some digital storage oscilloscopes like this.(1) There are some high performance DSOs which do linearity and transient response correction after digitizing, but that is not what we are discussing here. If someone is buying one of these for home use, then they do not need to work for a living.

author: tautech
author_rank: Super Contributor
timestamp: September 18, 2025, 09:32:39 pm
content: There is good reason why we no longer stock any 8bit entry level DSO's but it's not just down to the much improved precision but all the other features the SDS800X HD models offer.In early 2024 after just 2hrs with SDS814X HD we made this seemingly drastic decision and not one customer has asked for a less capable 8bit DSO.The hobbyist needs something to grow into as skill and understanding develops and these cheap 12bit DSO's offer all they need until you need push BW and capabilities to need a $ $ DSO.

author: David Hess
author_rank: Super Contributor
timestamp: September 18, 2025, 09:38:03 pm
content: Increasing integration will lead to higher resolution high bandwidth digitizers anyway, so 12-bit digitizers should displace 8-bit digitizers over time as their costs go down. But increasing integration is of marginal use for increasing the performance of the analog signal chain.The features I look for in a modern DSO gain nothing from increased resolution. I want one which can make a bode plot from the impulse response, which requires differentiation and phase/magnitude FFTs. Also, I want one with noise marker capability. Somehow all of these things are too difficult for DSOs newer than 30 years old.

author: Fixpoint
author_rank: Regular Contributor
timestamp: September 18, 2025, 09:58:54 pm
content: Quote from: 2N3055 on September 18, 2025, 08:45:09 pmPlease explain what bias let me buy UNI-T? Ah ... the "money bias"?QuoteOk, I admit, by referring to other people the matter becomes much easier. I shall add that trick to my playbook.QuoteWell, I wouldn't call it unusual but necessary. Every bit of resolution that you add at the test equipment side must be matched within the setup. If I add 2 or even 4 bit at the equipment side, it is not necessarily easy to argue why the setup is able to keep pace. At least for me. But of course not to the "other people" we already mentioned.QuoteThe logic is impeccable, I will not even try to argue with that.QuoteYou see right through me.QuoteDo I have a choice?QuoteWell, the only thing I did was to state my opinion and then to explain it, which is what this thread is about. Obviously, that doesn't suit everybody, especially those who are emotionally involved. "Vehement fighting" is more like being aggressive, using ad hominems and the like. Luckily that doesn't happen.QuoteWell, now you have completely penetrated my personality. Yes, a 28.000 EUR scope by R&S is what I actually crave for. I don't have anything else to wish for, I don't have any other project that might need my attention. Of all things, that's it. Unfortunately, I am not successful enough, and that pains me a lot. Because of that, I prefer the stance that hobbyists don't need 12-bit scopes.QuoteThe last remains of self-esteem that I had left now come crumbling down. When I leave the house in the morning, I always hope that nobody will notice that I only have a 10-bit scope. And these damn Siglent whippersnappers now sell those basically for free to everybody! Now everybody is better than me! I always felt it ... now I know it.Please don't be so harsh on me but understand my situation. When you don't have anything in your life, your scope becomes very important to you.QuoteI don't understand this part. As I said, I have UNI-T on my bench, even several of them. As far as I know, UNI-T doesn't count as luxury. (But please keep this to yourself, my day is already bad enough.)QuoteI don't get that. If someone keeps a 10-bit or even 8-bit scope, this would mean that 10 bit or 8 bit is enough and 12 bit wouldn't help that person enough to justify an upgrade. This logic is obviously flawed. 12 bit bit helps everybody, and it helps *a lot*. I rest my case.

author: 2N3055
author_rank: Super Contributor
timestamp: September 18, 2025, 10:20:24 pm
content: You are much better in making fun of me than making sense. Kudos and touche...I am not worthy.

author: EvgenyG
author_rank: Regular Contributor
timestamp: September 18, 2025, 10:40:54 pm
content: As a hobbyist, I can say that going from 8-bit to 12-bit is like going from VGA to Full HD. You never look back.

author: slavoy
author_rank: Regular Contributor
timestamp: September 19, 2025, 08:44:12 am
content: Right now:-Rigol DS1054Z 4ch 8-bit 1Gsa 24Mpts 50MHz stock - 369 EUR-Rigol DHO804 4ch 12-bit 1.25Gsa 25Mpts 70MHz stock - 360 EURWhat’s the point of even asking if I need 12 bits? The future is now, old man

author: Aldo22
author_rank: Super Contributor
timestamp: September 19, 2025, 09:11:01 am
content: It's actually quite simple: if I were to buy a new oscilloscope today, it would probably be a 12-bit model with 4 channels, simply because that's the state of the art right now and it's affordable.As long as I can do everything I need to do with my 8-bit oscilloscope with 2 channels or my analog scope, I won't rush to buy a new one.

author: Fixpoint
author_rank: Regular Contributor
timestamp: September 19, 2025, 09:41:31 am
content: Quote from: Aldo22 on September 19, 2025, 09:11:01 amExactly that's the point. *If* I were in the market *today*, I would probably buy a 12-bit scope -- not because I need it, but because that's how today's technology works.However, the OP's question was not "what would you buy", but "do you need 12 bit". And the answer is: No, I don't need it. Would I buy it? Yes, but just because it is cheap. Would I buy it for 10,000 EUR? Of course not! So, the point here is the price, not the requirements or the performance.

author: 2N3055
author_rank: Super Contributor
timestamp: September 19, 2025, 10:59:36 am
content: Quote from: Fixpoint on September 19, 2025, 09:41:31 amDo you need a car with 100 HP engine?No you don't. Fiat 126 had 25HP and people drove in it.Would you buy one today, when now you have better options?Otoh, if you had Fiat 126 and you were happy with it, why would you change it?You ended up saying same thing as I did. Fancy that...

author: Fixpoint
author_rank: Regular Contributor
timestamp: September 19, 2025, 11:13:29 am
content: Quote from: 2N3055 on September 19, 2025, 10:59:36 amI had hoped we are through with this ... well ... I will just quote myself, that should accelerate the process:Quote from: Fixpoint

author: Bud
author_rank: Super Contributor
timestamp: September 19, 2025, 11:50:08 am
content: I've been working in digital and RF for over 40 years, I still do not 'need' a 12-bit scope. I'd instantly trade one for a good Spectrum Analyzer instead.

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 19, 2025, 02:21:14 pm
content: Quote from: Fixpoint on September 19, 2025, 11:13:29 amYour argument doesn't make any sense. You completely gloss over all the actual benefits previously discussed in this thread. Hobbyists come here and ask questions, and those benefits are no longer a mystery to them.Then you ignore the fact that 8bit scopes aren't actually any cheaper than the newer, better 12bit scopes.Then, you agreed with Sinisa that if you were going to buy something today, you'd get the 12bit anyway.What's the point of arguing with somebody that you seem to agree with?

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: September 19, 2025, 06:38:13 pm
content: I know I'm probably alone with this opinion, but I don't really need a 12bit scope. Actually, I would always choose sampling rate over 12bit resolution.I.e. if I can have an 8bit scope with 5GSa/s (e.g. Siglent SDS5034X) or a 12bit scope with 2GSa/s (e.g. Siglent SDS2354X HD) for the same price, I'd always choose the 8bit scope without any hesitation.And that is exactly my problem with that 12bit portfolio of all major (and minor) scope manufacturers: since the 12bit area began some years ago, there is a stagnation or even regression regarding sample rate. Most entry level models feature 12bit now for a really good price, but they are still limited to <=1GSa/s at least if 2 or more channels are involved.In higher price ranges, the sample rates actually decreased. Even big players like LeCroy who offered reasonably priced 20GSa/s scopes fifteen years ago or so, reduced the sample rate to 5GSa/s or even 2.5GSa/s and invented marketing garbage like "enhanced sample rate" or "125GSa/s for repetitive signals" which makes it hard to impossible to find our the actual sample rate. Fact is, it iswaylower than what they offered 15 years ago with 8bit scopes.

author: paulca
author_rank: Super Contributor
timestamp: September 19, 2025, 07:10:22 pm
content: It's starting to sound like an audiophile argument in here.It comes down to different definition of "need". Modern convenience makes "cost" less relevant.If faced with 2 scopes of the same cost and features and one was 12bit and one was 10bit I would buy the 12bit.My scope is 10bit... maybe 8 bit. (Sigilent 1104X-E). The bit depth was not a major consideration. I am very happy with my choice. You may think I am wrong and that is perfectly fine. I'm sure there are better scopes, even for the same money, but life is short and this one works for my needs.Question. As a scope has an anlogue front end with gain and offset capabilities, the 8 bit resolution can be "zoomed" to a smaller part of the wave and thus show more detail than when viewing "full dynamic range". For example, if I take a basic rise on a square wave and zoom in to the repeat capture "knee" where it just starts to rise, the first 50mV of the full 5V transition....Am I correct in saying I have 8/10bit resolution of that 50mV range and thus ... if I was to matrix out all the measurements I could construct a far higher dynamic range than 8-10bits?EDIT: second question. Why can't scope do that anyway? Automatically, like modern cameras do. Take a dozen photos in 1/10th a second and combine them into an image with more dynamic range than a single shot could take.

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 19, 2025, 08:15:17 pm
content: Quote from: 0xdeadbeef on September 19, 2025, 06:38:13 pmI owned the SDS5054X and the SDS2504X HD at the same time. I agree with you; I much preferred the higher sample rate on the 5000X, but it wasn't enough to overlook the better features and display quality on the 2000X. I did find triggering faster and easier on the 5000X by comparison, and I liked that it had an external ref input.In the end, I'm sticking with the Magnova which maxes out at 1.6Gsa/s, but has a higher waveform rate, and it is a noticeable difference. Do I wish it had a higher sample rate? Of course! But I don't find myself lacking anything in reality. On the contrary, I chose it for the fantastic screen and external ref input and I've been very happy with it.

author: 2N3055
author_rank: Super Contributor
timestamp: September 19, 2025, 08:19:28 pm
content: Quote from: paulca on September 19, 2025, 07:10:22 pmYou can do that only to some extent.If you have DC voltage that has some AC content on top, then by using offset, you compensate out the DC offset so then you can magnify AC level to be bigger on the screen. That works, because in that case what preamp and ADC see is only what you see on the screen.If you have 10V P-P 1kHz squarewave with 10mV of other 1MHz signal on top, you cannot magnify only top portion. Because you are still pushin full 10 V P-P into scope frontend and you are going to get saturation and distortion.With more vertical resolution (10/12/14 bit) you can still keep 10 V P-P in full "view" for ADC and preamps, and "graphically" (like Photoshop zoom of hi res photo) zoom a portion and still see something.That is the difference.

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 19, 2025, 08:24:31 pm
content: You've explained that so many times now, evenIunderstand it.

author: Smokey
author_rank: Super Contributor
timestamp: September 19, 2025, 09:25:22 pm
content: My opinion: Most oscilloscope jobs answer questions in the range of "roughly, what is that fast(ish) signal doing right now". 8 bits is fine for that. The higher resolution scopes blur the lines with other specific bits of equipment like DAQs, which tend to answer much more specific questions using more and/or higher resolution measurements and then a bunch of back end processing. If you can get both in one piece of gear, that's cool.

author: David Hess
author_rank: Super Contributor
timestamp: September 19, 2025, 11:31:30 pm
content: I might consider what capability 12 versus 8 bit resolution enables.12-bit resolution allows greater dynamic range in FFT measurements, but for audio this is of limited use because audio circuits usually have much better performance. It would be useful for your class-a amplifier which lacks feedback, but not more useful than an 8-bit DSO. There are much better instruments for this sort of thing, including lower bandwidth higher resolution digitizers.It does not allow better settling time measurements. Oscilloscopes require external blanking to accomplish this. Overload recovery is not improved. The extra resolution is buried in noise.Would 12 bits help with viewing a reverse recovery waveform? I have never had a problem with 8 bits doing this.I once had to track down a glitch in the sine output of a function generator where an 8-bit DSO could not show it, but a 10-bit DSO, or an analog oscilloscope, could. On the other hand, an analog sampling oscilloscope could show it just fine, so there was something more than resolution going on.

author: slugrustle
author_rank: Frequent Contributor
timestamp: September 20, 2025, 12:03:32 am
content: OP here.I asked this question because I've been working on a switchmode power supply at work (PFC + LLC) and have been able to do everything I need with a Siglent SDS2504X+. Some MOSFET waveforms (gate and drain) are right at the limit of my equipment, especially looking at transients. It would be nice to have a higher sample rate (especially on all 4 channels), more bandwidth, and shorter rise time. I use Cal Test CT4206 probes (100x, 50Ω termination, 240ps rise time, 1.5GHz bandwidth) to look at gates, so my scope is the limiting factor there.The SDS6104A looks better to me than any 12-bit scope at a comparable price point, largely because it has 5GS/s on all channels. I thought that was odd because 12-bit is the new hotness, and I couldn't come up with a reason to need 12-bit more than sample rate, bandwidth, and rise time. That made me wonder what I'm misisng...Vertical zoom and offset came up in the thread. This is generally good enough for snubber tuning. I had to make a custom probe to look at MOSFET drain voltage on a synchronous rectifier so that only the ±1V part of the drain voltage near the rectifier thresholds would reach the scope and not the much higher peak drain voltage. That was a lot more effective than I imagine 12 bits would be.

author: tautech
author_rank: Super Contributor
timestamp: September 20, 2025, 03:42:52 am
content: Quote from: paulca on September 19, 2025, 07:10:22 pmThere is a lot you can do with the 8bit SDS1000X-E....if you know how.I find it simpler in Zoom mode where with V Pos you can place the DUT waveform part of interest on the 0V position and with System settings/Ref Pos set correctly you can increase sensitivity to vertically zoom in on the waveform of interest.There are limits though and they vary depending on the sensitivity ranges used.RTFMcheck datasheet.OTOH SDS800X HD has taken this to the next level where vertical and horizontal zoom get their own tab and window (identified with dotted lines) and when vertical zoom starts suffering from noise you can also apply a little averaging to the Z* tab and have a Math trace, all of which are based on the original channel input.Now you essentially have 3 channels and each with their ownandindependent control where if you choose you can hide any trace to focus on which is working best for your needs.....Hide does not mean inactive.Some screenshots for consideration....

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 20, 2025, 03:54:22 am
content: I agree with Rob and Sinisa. Vertical zoom detail on a nice 12bit scope is something I wouldn't give up. Sure, I could still get work done with an 8bit scope, but why?

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: September 20, 2025, 09:32:23 am
content: Quote from: KungFuJosh on September 20, 2025, 03:54:22 amMaybe for a proper sample rate that let's you see actualhorizontaldetails instead of interpolated pixels for higher speed signals?For the 10kHz triangle and 100kHz sine, the 1.6GSa/s sample rate is sufficient to show horizontal details. In this case, the 12bit resolution can really shine.In the example with the 10MHz square wave, only about every 4th pixel of the non-zoomed view would be based on actual measurement data if this was a single shot measurement (*). I.e. in a single shot measurement, the zoomed view would contain only 32 actually measured values. All the other pixels would be interpolated.(*) Of course, even in a cyclic measurement, the number of actually measured pixel per period doesn't change, but there is an interpolation over multiple periods, so the scope manufacturers would argue that the "equivalent" sample rate is much higher. I would argue though that the scope just makes it look like there were additional horizontal details measured for the actual (zoomed) period shown, but in fact, these details were gathered over dozens or hundreds of periods and then interpolated into one.And again, this is my only concern with 12bit scopes. The increase in vertical resolution is fine and dandy, but it usually comes at the price of much lower sampling rates, often disguised by fancy interpolation algorithms in an equivalent sampling mode. So, you trade (actual) horizontal resolution for vertical resolution. For the very same reasons, I was never a fan of "highres" modes and the like to increase the vertical resolution of 8bit scopes by interpolation over multiple measurements.

author: Aldo22
author_rank: Super Contributor
timestamp: September 20, 2025, 10:03:26 am
content: I only have a very simple 8-bit DSO. If I want to know more, I look at the waveform on my Hameg.Sometimes interesting things come to light.For example, this signal would be "connected" on my DSO using "Vector" display.In “Dots” mode, I would think it was a sampling artifact.Sorry, slightly off-topic.

author: Sorama
author_rank: Frequent Contributor
timestamp: September 20, 2025, 11:04:23 am
content: Quote from: 2N3055 on September 19, 2025, 08:19:28 pmWouldn’t AC coupling give you the same benefit in this particular case?

author: 2N3055
author_rank: Super Contributor
timestamp: September 20, 2025, 11:40:40 am
content: Quote from: Sorama on September 20, 2025, 11:04:23 amIt kind of would. But you then loose DC component.With current scopes they have very powerful measurements, so you can measure DC, AC, AC+DC RMS all at the same time.Couple in current probe and do all kinds of power analysis on top of that.When you only couple AC you lose all that.

author: mawyatt
author_rank: Super Contributor
timestamp: September 20, 2025, 02:10:31 pm
content: Quote from: 0xdeadbeef on September 20, 2025, 09:32:23 amInterpolation creates anestimateof in-between data values, whereasaveragecreates the direct accumulation of said values divided by the number of summations. Interpolation is anestimateandaveragean accumulated value of input data, so fundamentally interpolation is more error prone. There are various forms of interpolation (linear, quadratic, and so on) which tend to reduce the estimations errors at the expense of more complex computations with more than just 2 data points.Interestingly back in late 80s and early 90s we were working with systems with extreme dynamic range and attempting to simulate such with SPICE. We were having issues with FFT dynamic range artifacts which initially were thought to be convergence and/or numeric precision limited. Later it was discovered that SPICEinterpolationbetween time steps was the culprit as the time step algorithm produces non-uniform samples which needed to beinterpolatedinto uniform time steps for the post processed FFT.The time step interpolation algorithms in SPICE are quite good and related to the numerical integration methods which are also quite good. However these were not good enough for our unique needs and a special flavor of SPICE created where the time steps would be forced to known values and solutions solved at those specific times. Since the post FFT setup parameters (Window, length, time step) were known, these time steps were also known before the Time Domain simulation began and the simulation engine forced to solve at each discrete uniform time step. Post FFT analysis revealed simulation dynamic range limited by convergence criterion and numerical precision and notinterpolationerrors, later this technique was copied by Cadence!Best

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 20, 2025, 02:39:00 pm
content: Sooo, Zoom + Average and problem solved (if it really is a problem for somebody).

author: David Hess
author_rank: Super Contributor
timestamp: September 22, 2025, 12:47:41 am
content: Quote from: 2N3055 on September 20, 2025, 11:40:40 amHigher end DSOs may include offset capability where an adjustable offset is added to the input signal before some or all of the attenuation stages, allowing for instance 1mV/div sensitivity at a 10 volt DC offset. This is the capability which makes differential comparators like the old Tektronix 7A13 useful.