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I bought from Utsource once (they seem to have a great selection of stuff) and at the same time I also bought the same part from a no-name eBay seller. The markings on the parts were different between the two suppliers. Only one set matched the published data sheet from the manufacturer (from Utsource). As an extra precaution I emailed Utsource and flat out asked them if the parts were fake; of course they said they were not fakes. However, I've always looked on this pack of parts with some suspicion because unfortunately, a few rotten apples have spoiled the barrel and it's hard to trust any of the sellers from China for this kind of thing. Unfortunately, these parts were not available from the big box stores, probably obsolete. These days I'll use either new parts from Digikey or parts that I've personally taken out of an old piece of equipment made in the days before eBay.
Once i got this 2SC3280 !!! I returned them to the supplier and kept this one as a souvenir ...
And this TIP141 in the left is also a chinese Fake,but it looks a nice fake compared with the 2SC3280...
And this TDA2050 are real ones, i bought many years ago...
And this TIP141 in the left is also a chinese Fake,but it looks a nice fake compared with the 2SC3280...
And this TDA2050 are real ones, i bought many years ago...
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UTSource selling fakes?
I do believe my 2SC2671s were genuine Toshibas, but to be truthful, so long as they are inspec and operable, I don't much care. I guess when it all comes down to the point, I'd rather have the original and genuine article, but getting my project to work the way I want is the objective of the whole game.
I do believe my 2SC2671s were genuine Toshibas, but to be truthful, so long as they are inspec and operable, I don't much care. I guess when it all comes down to the point, I'd rather have the original and genuine article, but getting my project to work the way I want is the objective of the whole game.
Guys I am starting to get tired of UTsource.
Last year I struggled with an amp for hours due to fake STK.
I cut one open and it did not even have the same parts inside as the originals. Pin order was also far from original.
This week i got some TO-220 IXYS fets.
Gate capacitance looks ok.
Leakage at max voltage 250V is enough to heat the part a bit. Ok?
But RDSon is 20mohm instead of datasheet 50mohm.
I tested a used genuine part and it was 49mohm.
They do work in the class D amp.
Also the small circle in the plastic has a number on the original and none on the one from UTsouce.
If it is cheaper than anywhere else...guess 2 times if it is fake!
I am so tired of this.
Last time they were fair and refundes shipping and all, but forgiving them too many times just harms our planet.
Also I do not really care about the 13euros I spent...I care more about the amp!
By carefully selecting sellers I have usually gotten genuine electrolytics from ebay.
JFETs have always had some issue, shorted or not matched even if seller promises matched.
PowerFETs from china have mostly been fakes.
When high end mosfets have the RDSon of IRFZ44N you know the reason
Last year I struggled with an amp for hours due to fake STK.
I cut one open and it did not even have the same parts inside as the originals. Pin order was also far from original.
This week i got some TO-220 IXYS fets.
Gate capacitance looks ok.
Leakage at max voltage 250V is enough to heat the part a bit. Ok?
But RDSon is 20mohm instead of datasheet 50mohm.
I tested a used genuine part and it was 49mohm.
They do work in the class D amp.
Also the small circle in the plastic has a number on the original and none on the one from UTsouce.
If it is cheaper than anywhere else...guess 2 times if it is fake!
I am so tired of this.
Last time they were fair and refundes shipping and all, but forgiving them too many times just harms our planet.
Also I do not really care about the 13euros I spent...I care more about the amp!
By carefully selecting sellers I have usually gotten genuine electrolytics from ebay.
JFETs have always had some issue, shorted or not matched even if seller promises matched.
PowerFETs from china have mostly been fakes.
When high end mosfets have the RDSon of IRFZ44N you know the reason
@jlithen:
You should actually be happy if the Rds(On) is less!
I had been buying from Utsource for sometime and all of them worked. The only issue could be parameters. Just the last time, the opamp from Utsource gave an offset of around 20mV, while the same part from Digikey and Mouser gave less than 0.1mV. This is a result from 6 Nos. of Utsource part and 5 each from Digikey & Mouser.
I also had an issue with AD620s from a local supplier. Here, the part had issues of common mode voltage above 5V. The supplier vehemently argued that he was receiving no complaints from other buyers. He reluctantly gave references of 3 buyers, and after contacting them it was found that all of them used common mode voltage of near zero. Same part from a different supplier, belonging to a different batch worked well. I found later in AD website, someone else also had a similar problem.
You should actually be happy if the Rds(On) is less!
I had been buying from Utsource for sometime and all of them worked. The only issue could be parameters. Just the last time, the opamp from Utsource gave an offset of around 20mV, while the same part from Digikey and Mouser gave less than 0.1mV. This is a result from 6 Nos. of Utsource part and 5 each from Digikey & Mouser.
I also had an issue with AD620s from a local supplier. Here, the part had issues of common mode voltage above 5V. The supplier vehemently argued that he was receiving no complaints from other buyers. He reluctantly gave references of 3 buyers, and after contacting them it was found that all of them used common mode voltage of near zero. Same part from a different supplier, belonging to a different batch worked well. I found later in AD website, someone else also had a similar problem.
Let's put it this way.
How many 250V TO220 MOSFETs do you know that have 20mohm RDSon?
What I am saying is that this could be a 100V FET with new markings on it.
I am getting no reply from UTSource either...but it has not been very many days yet.
Also leakage of roughly 1mA is too high I read.
Never thought of it before but leakage for a mosfet should be microamps, right?
I'm so gonna buy a component tester. Actually I already bought a cheap atmega based one from China and it is on its way
Better test it well before I use it to draw any conclusions
Some serious HP or other good brand tester will likely cost thousands
But I am looking for one if someone has his/her for sale.
How many 250V TO220 MOSFETs do you know that have 20mohm RDSon?
What I am saying is that this could be a 100V FET with new markings on it.
I am getting no reply from UTSource either...but it has not been very many days yet.
Also leakage of roughly 1mA is too high I read.
Never thought of it before but leakage for a mosfet should be microamps, right?
I'm so gonna buy a component tester. Actually I already bought a cheap atmega based one from China and it is on its way
Better test it well before I use it to draw any conclusions
Some serious HP or other good brand tester will likely cost thousands
But I am looking for one if someone has his/her for sale.
These little testers can make a few, but usually inconclusive measurements. I doubt that anyone making a claim based on their accuracy (or the interpretation of their measurements) would be taken seriously. Of course, you may still get a refund.Actually I already bought a cheap atmega based one from China and it is on its way
Better test it well before I use it to draw any conclusions
The 3 recent Ebay examples I have used all operate with similar firmware and the results are close between them but not close to other testers using different test voltages and currents as appropriate for making datasheet based comparisons.
They are OK for checking small signal BJTs and JFETs within the limitations of their fixed test conditions. I don't think they have much value for tests on Mosfets and power devices generally so, if you don't want to overspend on something more useful for your own appraisal, like a curve tracer, the Peak Atlas DCA75 does a comprehensive curve tracing job on many parts. It's USB powered and uses software and your PC for the nice features of graphic presentation - allowing direct curve comparisons with stored test data too. It can also export graphics to Word and data to XL spreadsheets etc.
Other than as a customer though, I have nothing to do with the manufacturer or seller. Have a look: https://www.google.com.au/url?sa=t&...u3THN-rgYJXby3CxKWA&bvm=bv.95515949,d.dGYeven
The analogue to digital converter (Mega328) that generates the digital display seems to be a very low bit count..................I'm so gonna buy a component tester. Actually I already bought a cheap atmega based one from China and it is on its way
Better test it well before I use it to draw any conclusions
Some serious HP or other good brand tester will likely cost thousands
But I am looking for one if someone has his/her for sale.
I get dozens of devices that apparently read the same, or grouped with only two or three variations. It reads like that even though inside it might operate very differently.
But it is very useful for identifying an unknown component and confirming which leg is which function. It is also good in that it gives two parameters in the read out, eg Vbe and hFE for a BJT, but at an unknown Ib.
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Yes the Atlas is cheap, I guess I should buy one.
A friend who has it says they changed the SW in it so that it does not ruin bipolar devices with reverse voltage anymore.
I mostly bought the chinese tester for the first tests, such as:
-Is component shorted
-Does it contain a semiconductor
-Is it bipolar or FET
et.c.
I have seen people buying AudioFETs and getting a relabelled bipolars instead.
Also this device would immediately find the issue with the JFETs I bought, IDS approached infinity
I can do more manual tests for claims once my chinatester shows something weird.
A friend who has it says they changed the SW in it so that it does not ruin bipolar devices with reverse voltage anymore.
I mostly bought the chinese tester for the first tests, such as:
-Is component shorted
-Does it contain a semiconductor
-Is it bipolar or FET
et.c.
I have seen people buying AudioFETs and getting a relabelled bipolars instead.
Also this device would immediately find the issue with the JFETs I bought, IDS approached infinity
I can do more manual tests for claims once my chinatester shows something weird.
I think that if power transistors required multiple matching, anything that wasn't supplied in original manufacturing sequence like current production in original packing, would likely be unusable, whatever the batching codes and even if you could find other uses for the unwanted stock. Power Mosfets are more difficult again as they don't even match in die sequence like modern BJTs and are very expensive to sort and match in quantity.
UTsource, Dent and a few other China sources are there for desperates like vintage repairers and those too cheap to buy genuine OEM product from authorized dealers. Where else can you buy armfulls of Sanken TO3Ps for $1 ea? Come to think of it, how is it that all this alleged NOS product only comes from China? Why is not available from other manufacturing countries?
I suspect the answers aren't too hard to find, even in the more representative pics that show 2nd source product
UTsource, Dent and a few other China sources are there for desperates like vintage repairers and those too cheap to buy genuine OEM product from authorized dealers. Where else can you buy armfulls of Sanken TO3Ps for $1 ea? Come to think of it, how is it that all this alleged NOS product only comes from China? Why is not available from other manufacturing countries?
I suspect the answers aren't too hard to find, even in the more representative pics that show 2nd source product
Well the UTSource shop is in Shenzhen, their Ebay shop in Hong Kong. I expect their "sources" are based on locally traded goods which for Shenzhen as a manufacturing centre, would have to be largely local production.
I've come to accept that that Ebay pics may have nothing to do with the product we receive, other than type number and outline. It's frustrating to see a brand name quoted like Sanken in the product description but what we receive is either unbranded or an off-brand like K or ISC which may be OK, but in my book, this is plain dishonest product description.
I have found as you did though, that less popular parts have a much better chance of being original. The principles of supply and demand seem to work just as well in China
I do buy bench power supply and some switchers on ebay. But I do test them and I don't really want to use it in the real thing. For testing, it's ok.
I cannot refuse 2 24V 15A supply for $47 total including shipping. I put them in my test platform of my power amp. I am running 25V rail as the first test on the table. I did ran a few amps through the supplies for hours to make sure they survive.
for this saving, I can do the QA myself. I have no problem they actually said it's made in China, My issue is buy the name brand stuff from China.
I cannot refuse 2 24V 15A supply for $47 total including shipping. I put them in my test platform of my power amp. I am running 25V rail as the first test on the table. I did ran a few amps through the supplies for hours to make sure they survive.
for this saving, I can do the QA myself. I have no problem they actually said it's made in China, My issue is buy the name brand stuff from China.
Utsource recently promised that their transistors were the original Toshiba 2sc2240BL.
When they arrived I had my suspections that they weren't original...the printing/etching
style was different that those that I've seen that were original.
Then at a garage sale I got a beater amp. I opened it up
and washed it out with soap and water. Low and behold, it had about
20 of the Toshiba2sc2240BLs in them. They look totally different.
So maybe it was an earlier production run. Larger etching.
When my little Atlas tester came in it was proof beyond a doubt
the transistors weren't the Toshiba 2sc2240BL.
I emailed them back that I think they were false and they tested
poorly. Well they told me, that they inquired about it and found
out their supplier was from China.
There goes 60 of those little guys. Un Thank-You Utsource.
When they arrived I had my suspections that they weren't original...the printing/etching
style was different that those that I've seen that were original.
Then at a garage sale I got a beater amp. I opened it up
and washed it out with soap and water. Low and behold, it had about
20 of the Toshiba2sc2240BLs in them. They look totally different.
So maybe it was an earlier production run. Larger etching.
When my little Atlas tester came in it was proof beyond a doubt
the transistors weren't the Toshiba 2sc2240BL.
I emailed them back that I think they were false and they tested
poorly. Well they told me, that they inquired about it and found
out their supplier was from China.
There goes 60 of those little guys. Un Thank-You Utsource.
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