EEVblog #800 - Siglent 1000X Oscilloscope Teardown

[wraper]

I did not realize I need to chew the cheese for people, then put it in their mouth and then explain how they should swallow it. But let me fix my mistake.

In both scopes two low voltage switching power supplies located in the left top corner
both these power supplies are oriented west-east in both scopes
same RF shielding can size over the input stage
same type of relays in the input stage attenuators at same location inside the housing
same type of input buffer as in rigol DS1000 made from 4 transistors and the same topology: FET follower cascaded with a BJT follower, both loaded with current sinks.
same COSMO relays to switch AC/DC input stage coupling
the unpopulated FPGA footprints to the right of the RF shield are at exact same X-Y location
input stage LDO regulators in both scopes located to the righ to the RF shield
input stage LDO regulators use the same topology: 2x +5V, -5V
input stage LDO regulators are exactly the same part number, LP3878-ADJ (soic-8), TPS72301 (sot-23-5). How's that possible that two different companies and two different designers used exactly the same parts out of the full variety of parts available on the market?
same ADF4360-7 PLL for the ADC clock
battery holders are at almost the same location in mid-top of the board
same ADI Blackfin processor part
top three connectors - USB, LAN and BNC on the right are at exact same location (USB and LAN swapped)

And we were not shown the bottom of the Siglent PCB, surely the list would grow.

So unless the Chinese government dictates that power supplies must be placed at the top left corner of the PCB and requires their orientation must be west-east, and mandates all the other things listed above must be the same for all scopes, I do not see how this is not a copied design.
Who copied whom I do not care. They may as well have used same 3rd party source, a person or a company who did the designs for them or used a common design template pulled from Chinese iNet or passed around privately.

I'll sue you for copyright infringement if you dare to use the same voltage regulators like I do  . But honestly, your arguments are ridiculous. You also should complain that they have a display and a controls on the same positions  . Siglent should have been original and put the display on the bottom of the scope but controls on the back. BTW, half of the statements aren't even true.

[wraper]

In both scopes two low voltage switching power supplies located in the left top corner
both these power supplies are oriented west-east in both scopes

Yet that corner is completely different. There is a buzzer in Rigol and a flex connector in Siglent.

same RF shielding can size over the input stage

Did you measure the size? What I see, at least shields are different.

same type of relays in the input stage attenuators at same location inside the housing

Relay positions are completely different.

the unpopulated FPGA footprints to the right of the RF shield are at exact same X-Y location

Not exactly the same position and ram on opposite side. Footprints are completely different. BTW it is there because of the logic analyzer connector location  .

input stage LDO regulators in both scopes located to the righ to the RF shield

Because the trigger circuity is on the left  and ADC on the top.

input stage LDO regulators use the same topology: 2x +5V, -5V

Should be very unique.

input stage LDO regulators are exactly the same part number, LP3878-ADJ (soic-8), TPS72301 (sot-23-5). How's that possible that two different companies and two different designers used exactly the same parts out of the full variety of parts available on the market?

Very Unique jellybean parts I should say. Must be the core technology of the design.

same ADI Blackfin processor part

Blackfin from different family.

top three connectors - USB, LAN and BNC on the right are at exact same location (USB and LAN swapped)

That part actually looks quiet different. The sad truth is, even signal generators from many manufacturesr have back connectors on that position.

And we were not shown the bottom of the Siglent PCB, surely the list would grow.

Yeah, like they dared to use the ceramic capacitors for decoupling too.

[pascal_sweden]

At least four of the filter capacitors are Rubycon. Note the difference in the top vents. Can't tell for certain what the others are, but two of them could be Nichicon. The Rubycon parts they used aren't the high end ones either, about middle of the road. They might have gone with a Lelon brand on the main input filter so they could get those custom right-angle terminals instead of a standard 10mm snap-in.

They might indeed have chosen Lelon for the screw type aluminum capacitor:
http://www.lelon.com.tw/en/product.php#6

Is Lelon really that bad? They are Taiwanese, and have a joint venture with Elna in Japan.
http://listofcompanies.co.in/lelon-electronics-corporation/

"Lelon Electronics serves as one of the world’s top five electrolytic capacitor manufacturers operating five production facilities and six sales branches. In 1995, the company entered into a joint venture with ELNA (Japan), establishing ELNA-SONIC in Malaysia to produce aluminum electrolytic capacitors and PCB’s.
Lelon Electronics offers its products throughout Taiwan as well as to other countries that include India, the United States, Germany, Italy, and the United Kingdom. The company’s goal is to assist its customers to obtain top quality but lowest costs."

Here is an interview with the Lelon company
http://www.passivecomponentmagazine.com/602/

Note that I found a video on YouTube about counterfeit Rubycon capacitors


So now the question is: Are the filter capacitors really from Rubycon, or are they Rulycon? =)

[pascal_sweden]

Regarding the front panel:
===================

On the right side of the screen you have the control panel.
It seems that there are 4 small openings in that area: 2 on the left and 2 on the right.

Would that mean that you can remove it, and that it is some sort of latch mechanism?
Or why are those openings there at all?

Regarding the price comparison between Siglent and Rigol:
==========================================

Is it really correct to compare the Siglent SDS1202X with the Rigol DS2202?

The SDS1000X series does only have a 1GS/s sample rate, whereas the DS2000 series has a 2 GS/s sample rate. While the bandwidth is the same, the sample rate isn't.

Of course, there is no other Rigol scope that is a better fit, as the DS1000Z series does have 1 GS/s,
but it comes with 4 channels, and it does not come in a 200 MHz bandwidth model.

Regarding the measured waveform update rate:
===================================

Initially the waveform update rate was measured on the Siglent.
It turned out that in vector mode it is around 10K waveforms/s. Much lower than the advertised value.

Then the Rigol was tested. Using the same method it was measured to be around 45K waveforms/s.
But when the second channel was activated on the Rigol, the waveform update rate almost lowered by a factor of 10.

After that observation it was concluded that Siglent might actually be better, when 2 channels are used.
But was this actually tested? I can't see in the video that the second channel was active when the measurement of 10K waveforms/s was made!

It might be that the waveform update rate also reduces significantly on the Siglent.
Making it even lower than 10K waveforms/s when the second channel is active.