Rigol Rubbish DG800 - An expensive piece of Junk

[KungFuJosh]

The incessant need to call junk "cheap Chinese products" is unnecessary bigotry. China makes great products, and shite products. China itself doesn't determine the quality of the product, and pretending the source of manufacture has an effect on that is ignorant. Pay for something good, get something good. Pay for shite, get shite.

[coppice]

The incessant need to call junk "cheap Chinese products" is unnecessary bigotry. China makes great products, and shite products. China itself doesn't determine the quality of the product, and pretending the source of manufacture has an effect on that is ignorant. Pay for something good, get something good. Pay for shite, get shite.

When I look back over the last 50 years, the worst crap I've bought was German. Germans also made some of the best stuff I've seen. Most countries are capable of making both good and bad stuff, and do so. A lot of the best stuff China makes you just don't see in the west, as few people abroad want to pay a decent price for them, and they mostly sell to the domestic market.

[Aldo22]

The incessant need to call junk "cheap Chinese products" is unnecessary bigotry. China makes great products, and shite products. China itself doesn't determine the quality of the product, and pretending the source of manufacture has an effect on that is ignorant. Pay for something good, get something good. Pay for shite, get shite.

I almost agree.
But I would add a distinction:
Whether something is "shite" depends very much on whether you feel you have paid too much for it.
Some devices are OK for $50.
But if you pay $500 for the same device, then it's probably "shite" because you can get much better for that money.
Especially in the low-cost segment, every yuan counts and if there is a market for a $50 thing, then it will be produced for that.
You just can't expect the quality of a $500 product.
But I think that's OK and no reason to use bad language. Just don't buy it if it's not for you.

[KungFuJosh]

The incessant need to call junk "cheap Chinese products" is unnecessary bigotry. China makes great products, and shite products. China itself doesn't determine the quality of the product, and pretending the source of manufacture has an effect on that is ignorant. Pay for something good, get something good. Pay for shite, get shite.

I almost agree.
But I would add a distinction:
Whether something is "shite" depends very much on whether you feel you have paid too much for it.
Some devices are OK for $50.
But if you pay $500 for the same device, then it's probably "shite" because you can get much better for that money.
Especially in the low-cost segment, every yuan counts and if there is a market for a $50 thing, then it will be produced for that.
You just can't expect the quality of a $500 product.
But I think that's OK and no reason to use bad language. Just don't buy it if it's not for you.

The distinction is irrelevant since the country of manufacture had no impact on any of that.

[mawyatt]

Let's not forget that much of the upper tier OEM TE suppliers utilize many "off shore" resources to design and build various subassemblies or end products. The highly regarded HP/AG/KS often had such products, the Keysight/Rigol possible connection, or the LeCroy/Siglent possible relationship, or the possible similarity between some R&S and Tonghui instruments and so on.

The fundamental design, attention to detail, components, final assembly/test and after market support determines the overall quality and value of an instrument, not its origin!!

Best

[KungFuJosh]

Exactly. Tonghui's build quality is exceptional in our LCR meters. I think their support is abysmal, and people should buy the rebadged SourceTronic versions of those LCR meters, but that doesn't take away at all from the build quality.

[Aldo22]

The distinction is irrelevant since the country of manufacture had no impact on any of that.

Yes, I wasn't talking about Chinese products at all.

I meant something else.
A cheap product can be very welcome and you don't necessarily have to call it a bad name, even if it doesn't match the quality of more expensive models.

For example, I have an FY3224s signal generator.

Is it crap or "shite"? Yes, there are many aspects that seem cheap, starting with the appearance and the lack of a 3-wire power cable.

Would I buy it again or recommend it to others?
If you can get it for $50: yes!
It's simply the cheapest, usable 2-channel, 20Vpp, 24MHz AWG available.
And it works. Everything else is details in the specs.

Sufficient for hobbyists and you can be thankful that something like this exists.
If you know that you need a better device, you can get it elsewhere, but you don't have to insult the cheap one.

It's better to complain about expensive goods that don't meet your expectations. 

And here we are "on-topic" again.
The topic starter pays € 300 and rightly expects more than the $50 model offers.

[Berni]

To which specific model does your statement refer?

HDG3000B Series
HDG3000C Series
HDG6000B Series

Can you share your experience with us?
Information on these is relatively scarce.

It was a HDG2000B series.

I was pretty impressed with the hardware of it, but the software was so horribly buggy that it made it unusable. Tried a firmware update or two but then gave up on it and sold it. Later on when the Rigol DG1032 was released for a good price i bought it and was much happier with it.

It is possible the newer Hantek HDG models are better, but after the awful experience with it, i didn't even look at any other models.

[mawyatt]

Exactly. Tonghui's build quality is exceptional in our LCR meters. I think their support is abysmal, and people should buy the rebadged SourceTronic versions of those LCR meters, but that doesn't take away at all from the build quality.

I would give Tonghui a 10 on the TH2832, but a 3~4 on support (they did help with an issue early on), and for Hioki 10 on the IM3536, and maybe a 4~5 on support. Of course Tonghui is China origin and Hioki is Japan origin, both exceptionally good OEM TE suppliers in their respective product lines IMO.

Rigol and Siglent are much broader OEM suppliers tho, and both have demonstrated good value in most of their respective equipment offerings.

Personally think we should all thank Rigol, Siglent, and GW for thinking of us on the low end of the equipment totem pole, and quit bitching/nitpicked about features/performance/comparisons and so on 

Everything we've seen from these OEMs is quite good in overall value and performance, and thankful we have these selections at this low totem pole position

Best,

[KungFuJosh]

I meant something else.
A cheap product can be very welcome and you don't necessarily have to call it a bad name, even if it doesn't match the quality of more expensive models.

I totally agree with that. I have a TC3 that I think is great for what it is. I don't expect it to compare with serious TE, but it is a useful toy.

[Martin72]

The incessant need to call junk "cheap Chinese products" is unnecessary bigotry. China makes great products, and shite products. China itself doesn't determine the quality of the product, and pretending the source of manufacture has an effect on that is ignorant. Pay for something good, get something good. Pay for shite, get shite.

Or in short, the Chinese can't do magic either.
But this is a very interesting phenomenon of our time and applies to all products:
People don't want to spend money, then buy cheap things and are sorely disappointed when the quality isn't right....
The Amazon reviews are full of such tirades.
You can only say, buy something better.
If you can't afford it, then save up for it.
If you don't want that, then buy something good second-hand.
If you don't, then it's your own fault and stop complaining.

[Aldo22]

If you don't, then it's your own fault and stop complaining.

Almost. I would only rephrase the last sentence:
"If you don't, then it's your own decision."
Buying something cheap is a decision (see KungFuJosh's TC3) and not necessarily a fault.
It's only a fault if you expect your $50 thing to be as good as a $500 product.

[Martin72]

Yes, a true word.

[DaneLaw]

Its worth noting that Rigol do have a newer line of waveform-generators with the loaded label "PRO" with significantly better specs across the plate.
Datasheet specifications are posted below between the 2018 entry-line DG800 versus this new 2023/24 DG800PRO-line, which also is an entry/budget-series

Took the plunge on one back in November 2023 (DG821PRO) under the Singles-day-sale after a non-official Chinese Fluke/Rigol seller on Aliexpress to my surprise was willing to make up a new listing for one, though under the promise I extended the shipping-time to a handful of weeks, as it wasn't released yet in China, but it was only a matter of days.

It arrived in mid/late-December, quite an early unit 0000013, the final price was a tad under 300 euros (incl. both 25%EUVAT & delivery)
That specific seller (Fluke & Rigol store) all his listings' became invalid after 1-1-2024 with a sitemessage, "saying not available to your region".. it seems to be down to Aliexpress implementing new regional restrictions for EU from 1_1 2024 for certain brands.

Went for this unit, as I tried to speculate on the fact that there wouldn't be any actual hardware differences between the cheapest DG800PRO and the higher-end line of DG900PRO, and that the community down the line would be able to liberate this new line, as it wouldn't be a bad deal' if these specs were up for grabs for under 300 bucks [ 1.25GSa/s - 200MHz - 32M - 16-bits ] in a modern signal gen.

My biggest complaint so far, are the anoying fan.. it's a temp-regulated fan, that got a will of its own, and will cycle with minute differences up and down' that are far from pleasant,.. it can likely be optimised in firmware updates down the line, but then again, Rigol certainly dont have a curriculum that inspires any confidence for optimizing products after the fact.
It's more or less constantly on after around a +5-minute use-case and stays on... Looks like its the same noisy-fan as in Rigols DHO800/900-scope line, so in that regard the older series DG800 / DG900 and DG2000 do have an advantage, as they were all fan-less, if I recall correct, but also a lot slower. 125MSa/250MSa vs 625MSa/1.25GSa
Does get quite hot https://i.imgur.com/Cr5RSoD.mp4

Two things I do value a lot on Rigol's DGXXXPRO signal-gens, are the big high-res screen (7" 1024x600) that makes it way more enjoyable to explore & adjust features [UI https://tinyurl.com/2z87bkzy ]
Also, appreciate the ability to run it from power banks, and the mobility it gives.

The specs & tolerances DG800PRO (out of the box) versus the previous DG800 datasheet.
Quite a jump across the plate.

[bateau020]

Yes, the UI can be improved, Yes, the sync does not work reliably (and sometimes not at all), but I have the impression that the OP does not have the latest FW, nor has opened up the device to the max of its capabilities:
* make sure you have the latest FW (from 2021), as the original firmware was really bad.
* please know that "liberating" it to a DG992 is possible. That will at least get you up to 2MHz on the ramp, and 100MHz on sine wave (although, if you do not get it recalibrated, the amplitude will start to drop off at the higher frequencies. But hey, what do you expect?)

[thm_w]

The specs & tolerances DG800PRO (out of the box) versus the previous DG800 datasheet.
Quite a jump across the plate.

It is quite a jump for roughly the same price, assuming the full hack is eventually made public. Comparing DG992 to DG900 pro:
- 625Ms/s vs 250MS/s
- 200MHz vs 100MHz
- Maybe 5dB better harmonic/spurious distortion
- Though 5dB worse phase noise, seems to not have the same wave combining features, and probably other small details I missed.

Yes, the UI can be improved, Yes, the sync does not work reliably (and sometimes not at all), but I have the impression that the OP does not have the latest FW, nor has opened up the device to the max of its capabilities:
* make sure you have the latest FW (from 2021), as the original firmware was really bad.
* please know that "liberating" it to a DG992 is possible. That will at least get you up to 2MHz on the ramp, and 100MHz on sine wave (although, if you do not get it recalibrated, the amplitude will start to drop off at the higher frequencies. But hey, what do you expect?)

OP is running 00.02.06.00.01 which should be the latest. I mentioned hack above but don't know if they'd be interested, presumably they returned it already or are trying to return it.

[Sensorcat]

It seems that this question is still unanswered, so I give it a try.

Could you explain to me what is better about the 33120A than a modern AWG?
That's an honest, naive question. I would like to understand it.
When I look at the specs, I don't see much that sounds particularly great.

'Better' usually means 'better for me' and a lot of avoidable debate and trouble comes from omitting these two words. This means 'better' is subjective and everybody must decide on his own what specs are most important. It is interesting to compare the classic, now obsolete, HP/Agilent 33120A with the Rigol DG800, because you can probably buy them now at a similar price. Availability of a used 33120A may vary depending on your location, though.

I don't think that comparing the key signal specs is most important for a comparison. What makes the difference then?

DG800 advantages:

• 2 channel option, very important if you need 2 signals with fixed phase relation
• a large LCD, shows a lot of information at once
• much more memory for arb
• counter included
• much more functions for modulation/burst/sweep
• USB

33120A advantages:

• better build quality
• schematics and service manual available
• using a milestone design (the 33120A made DDS affordable) feels like driving a VW beetle
• EEs 40+ might know it already from work
• manufacturer has/had the reputation of providing elaborate, sophisticated, well-thought-out designs
• manufacturer has/had the reputation of not 'cheating' in specs/fineprint
• mature firmware
• GPIB

So how do I know that this device is good/better, other than by hearsay?

If you don't deep-dive yourself into this stuff, there is nothing better than hearsay, with the challenge that there are as many opinons as experts, or more...

[DaneLaw]

The specs & tolerances DG800PRO (out of the box) versus the previous DG800 datasheet.
Quite a jump across the plate.

It is quite a jump for roughly the same price, assuming the full hack is eventually made public. Comparing DG992 to DG900 pro:
- 625Ms/s vs 250MS/s
- 200MHz vs 100MHz
- Maybe 5dB better harmonic/spurious distortion
- Though 5dB worse phase noise, seems to not have the same wave combining features, and probably other small details I missed.

Wasn't the phase-noise values on the older units taken at merely 10MHz, while on the PRO its 20MHz and double the value? (another -3dBc to the PRO's value?)

- Took a look at the datasheets for different models, it seems to be uniform.
Phase Noise DG800 / DG900 / DG2000 series.
Typical (0 dBm, 10 kHz offset) 10 MHz: <-105 dBc/Hz
https://www.batronix.com/files/Rigol/Funktionsgeneratoren/DG900/DG900-Datasheet-EN.pdf

Phase Noise DG800PRO & DG900PRO
Typical (1 Vpp, 10 kHz) 20 MHz: <-110 dBc/Hz
https://www.batronix.com/files/Rigol/Funktionsgeneratoren/DG800Pro/DG800Pro_DataSheet_EN.pdf

On paper - the Rigol PRO-line of 2023/24 signal gens is a significant step up, but then again Im not sure how much confidence you can put into these specs.
I recall UNI-T UT962E claimed a very impressive (-125dBc at 10Mhz / 10kHz) which seemed to be a straight-out lie pulled from the air.
It performed even worse on phase noise than the cheapest entry Juntek JDS2900 DDS signal-gen and also significantly worse than a TTI (TG2511A) that merely claimed -115dBc 10MHz / 10kHz.   
Test https://youtu.be/hBDGztAnfI4?si=oOIr9gMOI6Bu2H5J

[Aldo22]

@Sensorcat

Thank you for your answer.
Yes, that's probably very subjective.

I don't actually see any advantages with the 33120A that would be convincing for me.
In my opinion, the device is simply outdated, if only because of its size (374mm depth, 4kg) and I'm not particularly interested in whether it can still be repaired in 20 years' time.
I don't own a museum 

But I do think that you have to compare specifications.

It certainly has advantages in terms of accuracy, harmonic distortion etc. but also some values that are no longer convincing.

Look, I have a new $130 oscilloscope (I won't name the brand because that's not the point) which has a built-in AWG (would cost $20 extra).
The prototypical "usual junk from China".

For example, I can use it to generate a single 20ns pulse that looks reasonable (Image). Rise time is approx. 3.6 ns.
Can the great 33120A do this too? Haven't found anything about this.

There are certainly areas where the 33120A is far superior, but these devices are not cheap even used (in Switzerland), if you can find them.
But above all, it's too clunky for me.

[Njk]

I don't actually see any advantages with the 33120A that would be convincing for me.
In my opinion, the device is simply outdated, if only because of its size (374mm depth, 4kg) and I'm not particularly interested in whether it can still be repaired in 20 years' time.
I don't own a museum 

Sure. But keep in mind that typical modern generator has its waveform output connector internally grounded. That's not the case with the obsolete instrument.

[m k]

I got the Rigol DG812, and i am really dissapointed... say furious.

I'd say that your expectations were out of the region.

Commercial rule of thumb is that lost customer is too expensive to get back.

Would it be better to sell it with some loss than keep it and feel the endless pain.
I'd say former.

Amount of money is not significant, its value is.

[thm_w]

I don't actually see any advantages with the 33120A that would be convincing for me.
In my opinion, the device is simply outdated, if only because of its size (374mm depth, 4kg) and I'm not particularly interested in whether it can still be repaired in 20 years' time.
I don't own a museum 

Sure. But keep in mind that typical modern generator has its waveform output connector internally grounded. That's not the case with the obsolete instrument.

Oh good feature. 33120A is spec to float 42V from earth.

DG800 Pro has both output grounds tied, but, isolated from earth via the USB power supply. Though I'm not sure how far you can really safely float them, as its not an advertised feature... But I would hope 42V is fine. Same with the DHO800, you are supposed to tie the chassis to earth, how many people actually do though..

[Martin72]

So many people will do this who don't know why the scope should actually be grounded.
At some point they will realize that it might have been a good idea after all.

[2N3055]

I don't actually see any advantages with the 33120A that would be convincing for me.
In my opinion, the device is simply outdated, if only because of its size (374mm depth, 4kg) and I'm not particularly interested in whether it can still be repaired in 20 years' time.
I don't own a museum 

Sure. But keep in mind that typical modern generator has its waveform output connector internally grounded. That's not the case with the obsolete instrument.

Oh good feature. 33120A is spec to float 42V from earth.

DG800 Pro has both output grounds tied, but, isolated from earth via the USB power supply. Though I'm not sure how far you can really safely float them, as its not an advertised feature... But I would hope 42V is fine. Same with the DHO800, you are supposed to tie the chassis to earth, how many people actually do though..

33120A isolated ground is just that. It serves the purpose to prevent DC/low frequency current ground loops while measuring.
It is not to be used as a fully floating signal source.
Other thing is that signal output to protective ground leakage and capacity is not specified in D.S. so for AC you might have much less isolation than you think...

[tautech]

For some reason it seems industry std is + 42V but not clear to me.
The discontinued SDG5000 range offered this as does the current USB AWG module SAG1021I.

P5
https://int.siglent.com/upload_file/user/SDG5000/SDG5000_DataSheet_DS02050-E03C.pdf

https://siglentna.com/product/external-arbitrary-waveform-generator-2/