catman Posted July 26, 2019 Share Posted July 26, 2019 G'day all, I've been reading a lot on this subject of late and I wonder if anyone has either encountered/ seen/possessed or used, 'fake' OPA2134 dual op amps? I ask this as although I have used many OPA2134's over the years I have seen a few that appear to be 'sub standard' in some respects (noisy for example). From my reading on this subject, it seems that many fake OPA2134's are simply 'restamped' TLO72's for example. Does anyone have any personal experience with fake or suspect OPA2134's? Regards, Felix. Link to comment Share on other sites More sharing options...
Addicted to music Posted July 26, 2019 Share Posted July 26, 2019 (edited) The TL072 is a nice chip. No, I’ve never encountered any, all my OPA come directly from Texas Instruments as samples free.. at the time. not sure whether you can get them free now. Then again I don’t take risks with solid state or any components I buy, they are sourced via RS, E14 or. Mouser. Edited July 26, 2019 by Addicted to music 2 Link to comment Share on other sites More sharing options...
oohms Posted July 27, 2019 Share Posted July 27, 2019 I got a set of fake opa2134 years ago.. These days for opamps, transistors etc, I only trust the digikey, element14 etc 1 Link to comment Share on other sites More sharing options...
Monkeyboi Posted July 27, 2019 Share Posted July 27, 2019 Although rare it is sadly a fact of life that fake parts are a reality in the electronics industry. Even large reputable (and not cheap) suppliers like RS, Digikey, Mouser, Element 14 and the suchlike aren't completely immune to occasionally sourcing components from questionable distributors. Certainly some brands of components are more likely to be "copied" than others simply based on the genuine part's reputation, specifications, cost and availability. So when I see normally expensive brands offered on Fleabay for ridiculously low prices the "don't go there" alarm gets triggered and I don't waste my time or my money purchasing what may very well turn out to be cheap and nasty rubbish. Years ago and probably is still the case, fake discrete semiconductor devices flooded the market mainly from Chinese suppliers using Fleabay as the means of retailing. As an example it wasn't uncommon for the humble 2N3055 power transistor in the metal TO-3 case to be faked. More than often they would fail well before reaching their maximum operating parameters. After having personally experienced a number of successive failures from a batch of devices from the same supplier I got out the junior hacksaw and cut off the top of one of the suspect devices only to discover to my horror that the die inside the case was a mere fraction of the size of the genuine 2N3055. Needless to say it was no surprise that the fake 2N3055s failed well below the collector current and power dissipation of the genuine article. So when I read that there are fake op-amps that either fail unexpectedly or have poor noise performance it comes as no surprise. One way to spot fakes is to examine the part ID or logo and compare it with a known genuine part. Quite often the markings are blurred, wrong font, wrong size or are faint on the fake part. Another dead giveaway is with some fake parts the number can be easily rubbed off using a cotton bud dipped in isopropyl alcohol. So when it comes to prototyping, production or repair of a product I always try to verify the lineage of my parts. Why? Because a substandard part can end up costing you $$$$ and time, not to mention frustration and reputation. Nothing worse than repairing something only to have it returned a short while later with the same problem or worse. In the case of the suspect fake OPA2134 op-amps one could spend hours chasing up a noise fault suspecting other circuit components, power supply noise or even circuit topology as the cause, only to be chasing a red herring instead. I am a member of a number of electronics groups on Facebook. In one group there is unfortunately a mindset amongst some of the members there that using substandard or fake parts is an acceptable practice citing that the group is all about "cheap" electronics. IMHO that creates a mindset in some of the younger (and even older novice) members that using substandard parts or parts not fit for purpose is okay as long as it appears to work on power up and the magic smoke doesn't escape in the first few weeks of operation totally ignoring safety or the consequential damage that might occur when the fake or substandard part fails. Apologies for the long post, but people profiting from vending fake parts for a huge profit really makes me angry. We buy components in good faith that what we will be receiving is the genuine article and expect those parts to perform to the manufacturer's published specification. In the case of the noisy OPA2134 op-amps I would contact the manufacturer and offer to send the IC(s) back to them for quality control evaluation. More than often they generally send you a bunch of replacements for free. Cheers, Alan R. 5 Link to comment Share on other sites More sharing options...
catman Posted July 27, 2019 Author Share Posted July 27, 2019 G'day mate, thank you for your very interesting and informative post. Rod Elliott has a similar section on counterfeit componentry on his ESP site that is also well worth reading. I am particularly interested in fake OPA2134's as I am a fan of that op amp yet I have used some that perform and sound fantastic, yet others used in much the same application that sound 'meh', and I've often wondered why? I've been going through my stocks looking for any suspect signs in identification etc. I guess that we all trust our component suppliers to deliver the 'genuine' item and I know that I always use reputable suppliers, however the slightly variable results that I have experienced make me wonder. Regards, Felix. Link to comment Share on other sites More sharing options...
Monkeyboi Posted July 28, 2019 Share Posted July 28, 2019 Today I thought I'd look into the typical selling prices for the OPA2134PA (8 pin DIL package) and I found some interesting results. Mouser $7.18 ea Texas Instruments Digi-key $7.17 ea Texas Instruments RS $7.04 ea Texas Instruments Jaycar $8.95 ea brand not stated Ebay $0.98 ea in quantities of 5. Price is inclusive of GST and delivery. Burr-Brown suspected fakes (see photo) The genuine BB chips have a notch cut into the end of the IC between pins 1 and 8 (see photo). There is a distinctive indentation indicating pin 1 which is closely aligned with the pin. The fake BB chips have no end notch and the pin 1 indicator is much larger and slightly offset from the pin. (see photo of the fake chips). I have included a photo of a assumed genuine Ti TL082CP which retails for about the $2.00 mark from major component retailers. Note similarity of the package to the fake BB OPA2134AP. So to me it comes as no surprise that some allegedly dishonest vendors might be rebadging much cheaper TL082 as an OPA2134. Cheers, Alan R. 5 Link to comment Share on other sites More sharing options...
Addicted to music Posted July 28, 2019 Share Posted July 28, 2019 (edited) OPA 2134 also comes in a SOIC package... This is something I refused and would never think about purchasing on eBay.. At least you can see the physical difference on a DIP package. Some SOIC there are no markings on them that correspond to the said product apart from a “sticker label” that’s on the pack, only a set of alpha numeric codes, I’m sure some of these codes are identification so when you connect with the manufacturer; TI, Onsemi etc they will verify, and also have your point of purchase info available. However these codes can be copied and printed on the device. We saw a device here that on SNA when a post with a pic was showing its markings to have a printing error where the print was smudge across the device, if that’s the case a visual inspection of the production line would be a straight reject, the prints cleaned off and reprinted correctly without any print quality to identify the package. On any devices, if the print for identification has quality issues it should raise loud alarm bells. edited: When products roll of the production line the ink markings for identification and bar coding are done with a ink jet that squirts microscopic droplets on to the product, these dry either via UV light or instantly depending on the type of ink used, They rarely smudge like someone using an ink stamp and slipping. The common issues with inkjet is blocked heads so you get deletions and not smudging. Edited July 28, 2019 by Addicted to music 1 Link to comment Share on other sites More sharing options...
LogicprObe Posted July 28, 2019 Share Posted July 28, 2019 49 minutes ago, Monkeyboi said: Today I thought I'd look into the typical selling prices for the OPA2134PA (8 pin DIL package) and I found some interesting results. Mouser $7.18 ea Texas Instruments Digi-key $7.17 ea Texas Instruments RS $7.04 ea Texas Instruments Jaycar $8.95 ea brand not stated Ebay $0.98 ea in quantities of 5. Price is inclusive of GST and delivery. Burr-Brown suspected fakes (see photo) The genuine BB chips have a notch cut into the end of the IC between pins 1 and 8 (see photo). There is a distinctive indentation indicating pin 1 which is closely aligned with the pin. The fake BB chips have no end notch and the pin 1 indicator is much larger and slightly offset from the pin. (see photo of the fake chips). I have included a photo of a assumed genuine Ti TL082CP which retails for about the $2.00 mark from major component retailers. Note similarity of the package to the fake BB OPA2134AP. So to me it comes as no surprise that some allegedly dishonest vendors might be rebadging much cheaper TL082 as an OPA2134. Cheers, Alan R. Love your work, Alan. 2 Link to comment Share on other sites More sharing options...
Batty Posted July 28, 2019 Share Posted July 28, 2019 I have worked in the defence electronics industry for all of my working life, fake components has always been a worry. We will not accept any item without a manufacturers Certificate of conformance. The risk is just too costly in both monetary and human lives. 3 Link to comment Share on other sites More sharing options...
Monkeyboi Posted July 29, 2019 Share Posted July 29, 2019 17 hours ago, Batty said: I have worked in the defence electronics industry for all of my working life, fake components has always been a worry. We will not accept any item without a manufacturers Certificate of conformance. The risk is just too costly in both monetary and human lives. Absolutely. If something fails you can't just "pull over" on cloud #17 for a quick pitstop to change a card or a component. Substandard, out of spec or fake parts just aren't worth the potential grief they can cause you. That's why verifying the lineage of components that will be used in critical applications is so important. Cheers, Alan R. Link to comment Share on other sites More sharing options...
Addicted to music Posted July 29, 2019 Share Posted July 29, 2019 1 hour ago, Monkeyboi said: Absolutely. If something fails you can't just "pull over" on cloud #17 for a quick pitstop to change a card or a component. Substandard, out of spec or fake parts just aren't worth the potential grief they can cause you. That's why verifying the lineage of components that will be used in critical applications is so important. Cheers, Alan R. in the Defence Industry, peoples lives depend on it.... same with the airline business... Components including solid state can fail of the production line, you can also have bad batch, a case in point of memory is Dan D'Agostinos Amps, where it went for a review test and they could not do mesurements and put it through its paces because an output transistor was hanging on dear life but eventually failed! Onsemi has had there Thermaltrak devices compromised where one manufacturer who promise a lifetime warranty had to replaced all the amp modules, now these are 500W @8ohms total of 20 Onsemi Thermaltrak devices per channel, and the directors sends out new amp channels X2 when only one goes into thermal runaway. I should know because I went to a SNA member to replaced these modules. 1 Link to comment Share on other sites More sharing options...
aussievintage Posted July 29, 2019 Share Posted July 29, 2019 2 hours ago, Monkeyboi said: Absolutely. If something fails you can't just "pull over" on cloud #17 for a quick pitstop to change a card or a component. Substandard, out of spec or fake parts just aren't worth the potential grief they can cause you. That's why verifying the lineage of components that will be used in critical applications is so important. I can remember process control computers from a now-defunct manufacturer, had little red blobs of paint on chips to show they had passed the computer manufacturers own tests. They'd take mil-spec components and at least verify the testing. Not sure that they didn't even select for better performance for some critical stuff. 1 Link to comment Share on other sites More sharing options...
Monkeyboi Posted July 30, 2019 Share Posted July 30, 2019 1 Link to comment Share on other sites More sharing options...
Decky Posted July 31, 2019 Share Posted July 31, 2019 (edited) So called "fake" chips sometimes come from the same factory that makes the real ones. They are just lower quality or complete rejects that were supposed to be destroyed but mysteriously find their way into the gray market and end up on ebay. I had voltage regulators that work fine but stop working after 1A while the spec sheet says 1.5A. The problem is much more complicated especially for large scale manufacturers. They might get an order that has 10% sub-standard parts but have to replace all of them and cope with the cost of shipping fault units back to base and everything that goes with that. NASA has a whole section that issues certificates of conformity for electronic components and keeps a black list of dodgy suppliers. Most of them are actually in the US who are sourcing parts from various shady places and reselling them domestically. On the other had there is absolutely no need for using OPA2134 from 1997 when there is so many equal or better modern opamps out there. Edited July 31, 2019 by Decky 2 Link to comment Share on other sites More sharing options...
Willafizz Posted March 7, 2020 Share Posted March 7, 2020 Scary topic! I am in the middle of a project that started out as a pair of active speakers and soon turned into a whole stereo system! This evening I was working on one of the analogue sections using BB OPA2134's. I was running out of parts and needed to borrow some OPA's from an earlier prototype. I cleaned up the parts with acetone and those cotton wool things you use to clean your ears (tops??). On some of the OPA's, it looked like I was removing a top coat of paint and after that, the marking was gone. The other ones seemed to cope with the cleaning operation. This made me immediately suspicious. Looking at this forum (thanks to all for the advice!), I can confirm that the ones losing the marking also have the pin 1 marker a bit offset - and the ones that kept the marking had the marker in the right place. All have the notch at the end though. By the way, the 'good' ones had a reference to Malaysia stamped in the middle on the underside. The 'bad' ones had another reference. To conclude, the acetone test might be a way of seperating the wheat from the chaff. 1 Link to comment Share on other sites More sharing options...
tubularbells Posted March 8, 2020 Share Posted March 8, 2020 Timely thread revival as I just picked up a bunch for my Ashly MFA800 amp restoration for Digi-Key. Look legit to me but who really knows? Link to comment Share on other sites More sharing options...
oohms Posted March 9, 2020 Share Posted March 9, 2020 Large domestic suppliers like digikey are usually fine Link to comment Share on other sites More sharing options...
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