Choosing between entry-level 12-bit DSOs

[gf]

Can the TSA do amplitude modulation?
Put in some AM at about 10% of the frequency.

It only supports a limited number of amplitude levels (I think 8 or so) for the the modulating signal, so it's a "stair step sine wave".
And the modulating signal is limited to 10 kHz.

EDIT: See also Erik's video: https://youtu.be/U2cw0bmuSLM?t=239

[awakephd]

Well, I had planned to drop out of this discussion, in part because I still had a month to go before I would have funds in hand to make a purchase ... but unexpectedly the funds have arrived early, so now the pressure is on to make a choice ... so I am back to seeing if I have fully understood the pros and cons of each, choosing between the Siglent SDS804X HD and the Rigol DHO804.

There are many things that seem to point to the Siglent SDS804X HD as the obvious choice (2G sample rate; better math functions; more USB ports; fewer bugs?). However, to the extent that I have been able to follow the discussion above, at least some of the advantage of the Siglent seem to be tied to more advanced topics than I expect ever to get into. (Yes? No?)

Meanwhile, there are some features that the Rigol brings to the table that I find attractive, including the slimmer size, possibility of powering from a battery pack, HDMI output, easy addition of wifi capability. VESA mount might also be valuable for my limited workspace.

I am getting ready to read back through the extended threads that detail performance, bugs, desired features, etc. for each of the units, but in the meantime, I have three specific questions:

The last feature I noted for the Rigol leads to the first specific question for this post: Have I understood correctly that there is no way to add wireless to the Siglent other than through the ethernet port?

Second specific question: I seem to recall reading something that suggested that the probes that come with the Rigol 804 are better (? or have a higher BW rating?) than those provided with the Siglent. Is that true, and should I care?

Third specific question: I think I would likely want to "hack" either of these units up to 100MHz and greater memory depth. From what I am seeing, this seems to be easier for the Rigol than for the Siglent - true? (This also connects to the previous question - if I want to hack up to 100Mhz, are the probes going to make that less successful with one vs. the other?)

[KungFuJosh]

There are many things that seem to point to the Siglent SDS804X HD as the obvious choice (2G sample rate; better math functions; more USB ports; fewer bugs?). However, to the extent that I have been able to follow the discussion above, at least some of the advantage of the Siglent seem to be tied to more advanced topics than I expect ever to get into. (Yes? No?)

Don't think that way. My actual use case is ridiculously simple (compared to the abilities of my scope) audio work. I usually feed a 1kHz sine wave into a piece of audio gear to trace issues (if there are any). Otherwise I will use the Bode function to get details of other audio gear. However, being on this forum, I have learned a LOT more and used significantly more functions that the scope has. People discuss things, I try it out, and if I didn't understand before, chances are now I might understand it a little better. I got the Batronix demo board and learned a lot from that too. There's always potential for more, but only to the limit of the tools you have.

Meanwhile, there are some features that the Rigol brings to the table that I find attractive, including the slimmer size, possibility of powering from a battery pack, HDMI output, easy addition of wifi capability. VESA mount might also be valuable for my limited workspace.

The only two benefits IMO to the Rigol are the VESA mount and the HDMI output. That's it. If those things are more important to you than actual measurement ability, then it's an easy decision. However, even the VESA mount can be done for Siglent with the help of 3D printing and a little creativity.

I am getting ready to read back through the extended threads that detail performance, bugs, desired features, etc. for each of the units, but in the meantime, I have three specific questions:

The last feature I noted for the Rigol leads to the first specific question for this post: Have I understood correctly that there is no way to add wireless to the Siglent other than through the ethernet port?

Incorrect. Almost any wireless bridge adapter can be connected to any device with an ethernet port. There are some specific small wifi bridge adapters which have been tested and work great for scopes without WiFi. There's also the possibility that Siglent might add direct WiFi dongle support in the future after tautech annoys them about it enough.

Second specific question: I seem to recall reading something that suggested that the probes that come with the Rigol 804 are better (? or have a higher BW rating?) than those provided with the Siglent. Is that true, and should I care?

Might be true, depending on which model you get. However, you shouldn't care. I exclusively use 3rd party probes from Probe Master. Some people also like Testec. While the supplied probes are usually sufficient, I like what I like. 😉

Third specific question: I think I would likely want to "hack" either of these units up to 100MHz and greater memory depth. From what I am seeing, this seems to be easier for the Rigol than for the Siglent - true? (This also connects to the previous question - if I want to hack up to 100Mhz, are the probes going to make that less successful with one vs. the other?)

Opposite. It's much easier for the Siglent. Siglent can go up to 200MHz and actually has a high enough sampling rate to support that. Rigol can go to 100MHz (or 125MHz) but is severely limited by its sampling rate. Siglent also has better memory depth.

There are specific posts in this thread covering most of this, but a summary doesn't hurt.

Rigol Pros: HDMI, VESA mount, WiFi built in.

Siglent Pros: Speed, memory, sampling rate, stability, superior Bode and FFT, support, etc. Also amazing documentation in Performa01's demo thread for the SDS800X HD.
VESA mount and WiFi can be added to the Siglent, HDMI cannot.

For adding WiFi, personally I would probably try the GL.iNet GL-MT3000. Others have used the less expensive TP-Link N300 and the TP-Link AC750 would also be an option.

Thanks,
Josh

[Mechatrommer]

Meanwhile, there are some features that the Rigol brings to the table that I find attractive, including the slimmer size, possibility of powering from a battery pack, HDMI output, easy addition of wifi capability. VESA mount might also be valuable for my limited workspace.

well you've made you choice congratulation! There's nothing wrong really with rigol to begineer, we hope they will fix bugs as before.. even more so with rival appearance from sds800x.

About probe, there's more catch, such as loading at hi freq.. and technique to avoid gnd loop etc. since you dont really concern, built in probe should be fine, you'll learn as you go. I never have a need for fancy 3rd party hi -z passive probe, if i want hi freq i'll go 50ohm 1x coax, or active probe. either way you have to pay extra money. ymmv.

[DaneLaw]

Can the TSA do amplitude modulation?
Put in some AM at about 10% of the frequency.

It only supports a limited number of amplitude levels (I think 8 or so) for the the modulating signal, so it's a "stair step sine wave".
And the modulating signal is limited to 10 kHz.

EDIT: See also Erik's video: https://youtu.be/U2cw0bmuSLM?t=239

The TinySA supports 8-point interpolation, while the Ultra can muster up to around 128 points depending on modulaton frequency.

[shapirus]

Rigol can go to 100MHz (or 125MHz) but is severely limited by its sampling rate.

Incorrect.

It can be unlocked to 250 MHz, which is actually ~290 MHz (-3 dB), and it has no aliasing issues at that frequency in single-channel mode (1.25 GSa/s).

With two channels operating (625 MSa/s), aliasing starts to become noticeable only after 230 MHz, but it remains still usable at 250 MHz.

The 100-125 MHz upper usable limit is only relevant when 3 or 4 channels are enabled (312.5 MSa/s sampling rate).

[Fungus]

There are specific posts in this thread covering most of this, but a summary doesn't hurt.

Rigol Pros: HDMI, VESA mount, WiFi built in.

Smaller size, battery option, more accessible UI, easy/neat Wifi with web/ftp access to the 'scope...

Rigol can go to 100MHz (or 125MHz) but is severely limited by its sampling rate.

Nope. Rigol can go to 280Mhz measured bandwidth, and shows signal far beyond that.

I wouldn't leave it at that bandwidth for general use but it's there if you need it and it only takes about 10 seconds to switch the model.

There's also 225MHz, 200Mhz and 125MHz options.

The lower sample rate sounds scary but when you're looking at real-life signals with probes clipped onto wires? Not so much.

(And there's no problem at all with 1 or 2 channels)

[Fungus]

Can the TSA do amplitude modulation?
Put in some AM at about 10% of the frequency.

It only supports a limited number of amplitude levels (I think 8 or so) for the the modulating signal, so it's a "stair step sine wave".
And the modulating signal is limited to 10 kHz.

EDIT: See also Erik's video: https://youtu.be/U2cw0bmuSLM?t=239

The TinySA supports 8-point interpolation, while the Ultra can muster up to around 128 points depending on modulaton frequency.

Ok, no problem.

I'm just wondering how the Siglent is cheating to get that display. The Rigol isn't doing anything wrong, it's doing the correct math for the limited information it has.

The original Signal can be reconstructed with much wider filters but they'll only work if the signal is perfectly periodic.

I was wondering what happens if the signal isn't periodic. It could go very wrong.

[2N3055]

There are specific posts in this thread covering most of this, but a summary doesn't hurt.

Rigol Pros: HDMI, VESA mount, WiFi built in.

Smaller size, battery option, more accessible UI, easy/neat Wifi with web/ftp access to the 'scope...

Rigol can go to 100MHz (or 125MHz) but is severely limited by its sampling rate.

Nope. Rigol can go to 280Mhz measured bandwidth, and shows signal far beyond that.

I wouldn't leave it at that bandwidth for general use but it's there if you need it and it only takes about 10 seconds to switch the model.

There's also 225MHz, 200Mhz and 125MHz options.

The lower sample rate sounds scary but when you're looking at real-life signals with probes clipped onto wires? Not so much.

(And there's no problem at all with 1 or 2 channels)

Your pointed out that advantages are telling us that it would be better as a portable multimedia device.
Switching the device BW by constantly tinkering with system apps is not same as having device that simply works.
It seems to me that people that own DHO800 Rigol scopes are buying that device to play and tinker with the scope itself, not to use it. There are also people that would buy a scope to work on their projects and want scope to simply work. To each, their own.

And again with channels. If that is your argument then fine.
But that is a 2 ch scope then.
Because with 4 ch it is not working properly.
Or 4 Ch with 70MHz.
But you cannot have it both ways.

Difference is that "the other" scope actually does work as 4ch 200MHz BW scope.
At all times, no special conditions..

So one scope is simple scope with multimedia and tinkering "built in" and the other device is serious instrument, designed to work as proper measurement instrument, with no gizmos and frills.

One is for hackers/makers and people that like to play with things, the other is inexpensive serious instrument (within obvious limits of it's class) for people that need that.

[2N3055]

Can the TSA do amplitude modulation?
Put in some AM at about 10% of the frequency.

It only supports a limited number of amplitude levels (I think 8 or so) for the the modulating signal, so it's a "stair step sine wave".
And the modulating signal is limited to 10 kHz.

EDIT: See also Erik's video: https://youtu.be/U2cw0bmuSLM?t=239

The TinySA supports 8-point interpolation, while the Ultra can muster up to around 128 points depending on modulaton frequency.

Ok, no problem.

I'm just wondering how the Siglent is cheating to get that display. The Rigol isn't doing anything wrong, it's doing the correct math for the limited information it has.

The original Signal can be reconstructed with much wider filters but they'll only work if the signal is perfectly periodic.

I was wondering what happens if the signal isn't periodic. It could go very wrong.

It is amazing how people project their own mentality to others.

There is no cheating. Just accept it.
It looks exactly the same if you single shot it.
That is your nonrepetitive signal.
It is just done right.

Why the other manufacturer's device doesn't show right? I don't know.
But it is them that, on several occasions, have shown bad reconstruction of data and cheating of all sorts...

[Harrow]

Meanwhile, there are some features that the Rigol brings to the table that I find attractive, including the slimmer size, possibility of powering from a battery pack, HDMI output, easy addition of wifi capability. VESA mount might also be valuable for my limited workspace.

The last feature I noted for the Rigol leads to the first specific question for this post: Have I understood correctly that there is no way to add wireless to the Siglent other than through the ethernet port?

Second specific question: I seem to recall reading something that suggested that the probes that come with the Rigol 804 are better (? or have a higher BW rating?) than those provided with the Siglent. Is that true, and should I care?

Third specific question: I think I would likely want to "hack" either of these units up to 100MHz and greater memory depth. From what I am seeing, this seems to be easier for the Rigol than for the Siglent - true? (This also connects to the previous question - if I want to hack up to 100Mhz, are the probes going to make that less successful with one vs. the other?)

I don't want to stop you from getting the Siglent because no doubt it's a great little machine, but I'll answer your questions regarding the Rigol, simply because I can. I've been using it for a couple of hours a day for the last few weeks and continue to be happy with it.

1. Wi-Fi - Super simple to enable this and remote web control is pretty good. You can access and adjust pretty much everything you'd want.
2. Bandwidth - the hack to 100 Mhz is equally simple.
3. Sampling rate limitation - I don't think there's any need to worry about all this talk of 4-channel operation being at lower sampling rate. Whenever you want to be sure of something, it only takes a few seconds to switch off the other channels momentarily to get the 1.25 GS/s, which puts you in the realm of 200 MHz, only to find that the waveform doesn't change and then you pull off the probe hooks and start using the spring clip and realise that has 10 times more impact.
4. HDMI - I've done this into my 65-inch flatscreen and it looks pretty impressive, but Wi-Fi web control partly negates the need for the HDMI.
5. Hacking - I'm looking forward to having a poke around just for the fun of it.
6. Size - I didn't even realise it had a slimmer profile than the Siglent, but now I know that, I am happy I have the Rigol as I'm currently using it in an extremely confined space.

[gf]

The original Signal can be reconstructed with much wider filters but they'll only work if the signal is perfectly periodic.
I was wondering what happens if the signal isn't periodic. It could go very wrong.

No, it does not have to be periodic. "Perfect reconstruction" only requires that the original signal sampled by the ADC sampled was bandwidth-limited.

And with a realizable real-world reconstruction/interpolation filter, this bandwidth limit is not 0.5*sample_rate, but lower. For the Rigol, it seems to be about 0.3*sample_rate.

Just make sure that the signal you feed into the ADC does not contain any frequency content above 0.3*sample_rate, and the interpolated waveform you see on the screen will be the same as the waveform sampled by the ADC (at least almost the same -- small residual errors are unavoidable in practice).

If you violate this precondition, perfect reconstruction is not possible and the resulting distortion is implementation-dependent.

[Fungus]

No, it does not have to be periodic. "Perfect reconstruction" only requires that the original signal sampled by the ADC sampled was bandwidth-limited.

Nope.

The signal in this image is bandwidth limited (5Hz signal, 11Hz sample rate) but sin(x)/x won't reconstruct it unless the filter is infinitely wide and the signal is periodic (which can't happen in practice).

[Fungus]

There is no cheating. Just accept it.
It looks exactly the same if you single shot it.

What does single shot have to do with it?

You seem to be saying Rigol don't even know the basics of signal theory.

[Mechatrommer]

No, it does not have to be periodic. "Perfect reconstruction" only requires that the original signal sampled by the ADC sampled was bandwidth-limited.

Nope. The signal in this image is bandwidth limited (5Hz signal, 11Hz sample rate) but sin(x)/x won't reconstruct it unless the filter is infinitely wide and the signal is periodic (which can't happen in practice).

man what are you smoking? please focus on gf's word here "realizable real-world reconstruction/interpolation filter"... true Sinc by theory cant be implemented in real world, so professors have to find a way to make it "realizable" or "practical", similar to Fourier Transform, without DFT or FFT, real Fourier Transform will not be "realizable" because real FT is infinitely long. go read some literatures on how to make those "realizable", i cant comprehend them myself but at least i got some idea. the FFT you keep bragging about, is one crippled version of FT that brings some complications with it, ymmv.

[mawyatt]

We have both the Siglent SDS800 and the Rigol DHO800, well the Rigol is a clients that has run into financial difficulty, so likely to remain at "The Labs" for awhile.

We acquired the Rigol for said client and the plan was to teach them the DSO use for a specific application, so spent some time and became familiar with such.

Simply put, Rigol hit a Home Run with the DHO800 introduction, with the custom 12 bit Chip Sets, small form factor, nice screen (altho a bit dim), solid build, excellent UI, VESA, HDMI, nice probes and so on at a price point most could afford. As one popular Rigol Fanboy put it, "Game Changer"!! Which was true, this little Rigol DSO was quite remarkable in every respect, especially considering the price point!!

Needless to say we were impressed with this Rigol DSO, and this was our 1st direct "hands on" with any Rigol product, similar to our experience with our 1st "hands on" with our Siglent SDS2000X+ a few years back, both these folks have really done a superb job   

When the SDS800 was available we decided to spend our own nickel, well the Rigol so far has ended up on our nickel as well

Simply put, Rigol hit a Home Run with the DHO800 introduction, then Siglent hit a Grand Slam with the SDS800 introduction 

As good as the Rigol DHO800 is, and it's good, really good is every aspect, the Siglent SDS800 is just overall better IMO.

We have no brand preference, just have a preference for the best instrument for the task (know thy instrument so to speak), and when one factors in cost, the best value instrument for the task!!

Bottom line is you can't go WRONG with either the Rigol or Siglent, but as 2N3055 mentioned the Siglent is the more "Pro Like" Instrument, and more in-line with making quality/trustworthy measurement/observations rather than just playing around and tinkering, which is fun BTW    

So when we reach for a DSO, now we reach for the SDS800, usually with the Rigol probes tho (these are really good, better than the Siglent IMO) 

Anyway, how either one of these can be offered at this price point is remarkable and a tribute to both Rigol and Siglent, but honestly from a well seasoned old Pro who's used every piece of TE imaginable, one would expect the Siglent to cost ~10X......yes it's that good!! Heck one would expect the Rigol to cost ~3X also!!!

BTW we are NOT open for doing direct comparisons, we'll let that reside in the hands of others!!

Of course, as always, YMMV!

Best,

 

[KungFuJosh]

Difference is that "the other" scope actually does work as 4ch 200MHz BW scope.
At all times, no special conditions..

Exactly. My comparison was fair, and compared them as 4 channel scopes with what their sampling rates actually allow.

The argument that it's not that hard to disable 3 of the channels on the Rigol to get higher bandwidth is comical, not professional.

one would expect the Siglent to cost ~10X......yes it's that good!! Heck one would expect the Rigol to cost ~3X also!!!

I think that's a great comparison. Both scopes are great at what they do, and cost about the same, but the Siglent is worth 10x what it costs, and the Rigol only 3x what it costs. It's a great value either way, but one is clearly superior...if you want to use it as a tool to do work. If you want to hack and tinker with a the scope as a toy, then YMMV.

[Fungus]

Simply put, Rigol hit a Home Run with the DHO800 introduction, then Siglent hit a Grand Slam with the SDS800 introduction 

Yep, there's no way the Siglent boys will ever make me regret buying mine or that it's in any way insufficient for my work.

As good as the Rigol DHO800 is, and it's good, really good is every aspect, the Siglent SDS800 is just overall better IMO.

On paper, sure, but my question is how much of that translates into an advantage in practice.

Sure, there's some people who need 4 channels at 200Mhz over 50 Ohm coax that but I'm not buying that every single EEVBLOG member does.

I'm also not buying that those people wouldn't be far better off with a 2000-series 'scope at 350MHz. which seems to be an area where Siglent is supreme. "200Mhz" seems like a very arbitrary number to me.

So let's list the advantages of each and not try to say one is "better". Numbers aren't everything, one size doesn't fit all.

So when we reach for a DSO, now we reach for the SDS800, usually with the Rigol probes tho (these are really good, better than the Siglent IMO) 

Rigol has their own ASICS so Siglent's margins are probably a lot thinner to be able to be sell at the same price point. Things like the probes will be the first to suffer.

[Mechatrommer]

Difference is that "the other" scope actually does work as 4ch 200MHz BW scope.
At all times, no special conditions..

The argument that it's not that hard to disable 3 of the channels on the Rigol to get higher bandwidth is comical, not professional.

comical or not, professional or not, sds800x cannot see 400-500MHz even on one channel active, prove me wrong.

[KungFuJosh]

comical or not, professional or not, sds800x cannot see 400-500MHz even on one channel active, prove me wrong.

🤣🤣🤣 I don't need to. The FACT of REALITY is that if you're trying to measure outside of the scopes designed bandwidth, then the results simply won't be accepted by any professional. The results shapirus showed of his DHO800 measuring 500MHz were TERRIBLE. If you think that's something to be proud about, I don't know what to tell you.

Do you need to measure a 500MHz signal? Your scope better be CERTIFIED to do so, or you could be subject to legal action when the product you're trying to sell doesn't meet specs, or the device you certified as functional isn't. Standards and reality matter, unless you're talking about a toy.

Are you looking for a toy or a tool?

[wasedadoc]

No, it does not have to be periodic. "Perfect reconstruction" only requires that the original signal sampled by the ADC sampled was bandwidth-limited.

Nope.

The signal in this image is bandwidth limited (5Hz signal, 11Hz sample rate) but sin(x)/x won't reconstruct it unless the filter is infinitely wide and the signal is periodic (which can't happen in practice).

That signal has components above 5.5 Hz.

[mawyatt]

On paper, sure, but my question is how much of that translates into an advantage in practice.

That's the point we don't "practice", we performed in real time, no backups, or woops, or awe sh*its, missed that, our career and reputation were/are on the line in everything we did/do.

Today things are a little less stressful as we are semi-retired, but still adhere to the "no excuses" policy wrt to electronics design, and the Siglent is simply our more Pro Level instrument IMO.

Please remember we have both Rigol & Siglent, and don't need to defend nor exaggerate the performance of either

Of course YMMV

Best,

[nctnico]

The original Signal can be reconstructed with much wider filters but they'll only work if the signal is perfectly periodic.
I was wondering what happens if the signal isn't periodic. It could go very wrong.

No, it does not have to be periodic. "Perfect reconstruction" only requires that the original signal sampled by the ADC sampled was bandwidth-limited.

And with a realizable real-world reconstruction/interpolation filter, this bandwidth limit is not 0.5*sample_rate, but lower. For the Rigol, it seems to be about 0.3*sample_rate.

Agreed. In addition I'd like to add that sin x / x reconstruction (which is a relatively simple filter to implement) can reconstruct a sine wave little over  fs / 2.5  (0.4 * fs). Anything less I consider broken. I have come across a few DSOs which had trouble doing sin x /x reconstruction at fs / 2.5 but their manufacturers fixed the firmware quickly. Bottom line: consider the current Rigol reconstruction as broken and needs fixing.

[Antonio90]

comical or not, professional or not, sds800x cannot see 400-500MHz even on one channel active, prove me wrong.

🤣🤣🤣 I don't need to. The FACT of REALITY is that if you're trying to measure outside of the scopes designed bandwidth, then the results simply won't be accepted by any professional. The results shapirus showed of his DHO800 measuring 500MHz were TERRIBLE. If you think that's something to be proud about, I don't know what to tell you.

Do you need to measure a 500MHz signal? Your scope better be CERTIFIED to do so, or you could be subject to legal action when the product you're trying to sell doesn't meet specs, or the device you certified as functional isn't. Standards and reality matter, unless you're talking about a toy.

Are you looking for a toy or a tool?

Your scope will not be "certified" whatever that means when out of cal either, and I bet most, if not all of your equipment is not calibrated regularly.
Certainly mine isn't, and I intend that to stay that way.

I couldn't care less about 500MHz signals right now, which doesn't mean being able to visualize that signal is completely useless for everybody. Very few people buy either of the scopes discussed in this thread for certification and measurements in which legal liability is involved, and nobody without periodic calibration.

Let's keep the discussion where it belongs. I do agree that the SDS800X-HD is a better oscilloscope overall. I can also see why, for basic use, the DHO800 can be more than enough and in that case in particular it might be a better purchase due to some usability and convenience advantages.

That being said, I just got my SDS800X-HD. I'm thinking of buying a DHO800 just to compare them thoroughly, but it's a bit of an expensive thought.

[mawyatt]

That being said, I just got my SDS800X-HD. I'm thinking of buying a DHO800 just to compare them thoroughly, but it's a bit of an expensive thought.

Go for it, we can compare notes

Edit: You can use the Rigol's better probes as an excuse, need, requirement to acquire such

Best,