# TL072 vs "TL072"



## temol (Aug 4, 2022)

I did not want to hijack the "TL072 substitute? (They're expensive now)" thread, hence a separate topic.

Short visual and audio comparison between fake and genuine TL072 chips.

Simple setup, one inverting stage.

Genuine vs fake







and LM358 for a comparison. 





Here some oscilloscope images from a working circuit.




















And simple audio comparison. There are 6 sounds in the file. 1-3-5 fake chip, 2-4-6 geniune.
In my opinion, the difference is best heard in the first two, with a single E string.


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## MichaelW (Aug 4, 2022)

temol said:


> I did not want to hijack the "TL072 substitute? (They're expensive now)" thread, hence a separate topic.
> 
> Short visual and audio comparison between fake and genuine TL072 chips.
> 
> ...


Do all the fake ones have the little "dish" to orient them?


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## temol (Aug 4, 2022)

In my case - yes.


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## szukalski (Aug 4, 2022)

Really appreciate the work gone into this, the fake IC market is off the scale now, I can't take the risk anymore where it was ok just a while ago. A good lesson to learn.

Interesting is the batch number (18MDSHY) which I have found from multiple providers now, with different packaging (dish, dot, dish+dot) often in the same batch.

LM13700N is another I got burnt by in the past, you get what you pay for.

I'm wondering how long until we see fake SMDs. I have tried a few MMBFJ201 and MMBF5457 with success, but I guess it's a matter of time..


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## mybud (Aug 4, 2022)

szukalski said:


> Really appreciate the work gone into this, the fake IC market is off the scale now, I can't take the risk anymore where it was ok just a while ago. A good lesson to learn.
> 
> Interesting is the batch number (18MDSHY) which I have found from multiple providers now, with different packaging (dish, dot, dish+dot) often in the same batch.
> 
> ...


Yes indeed, don't mention BBD chips. Oops, sorry, I just did, didn't I?


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## szukalski (Aug 4, 2022)

mybud said:


> Yes indeed, don't mention BBD chips. Oops, sorry, I just did, didn't I?


I have had mixed success, out of 10 3102/3207 pairs, I got 3 usable ones out of it. Again, never again and not recommended.


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## fig (Aug 4, 2022)

Thank you for providing this!

I will usually buy a sampling from a new vendor and test before committing to a large order. It’s also  understandable that faulty or even fake chips can make their way into an otherwise great vendor’s inventory without their knowledge.

An alternative to testing a suspect chip with is simply to put one in a working circuit and listen.


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## szukalski (Aug 4, 2022)

fig said:


> An alternative to testing a suspect chip with is simply to put one in a working circuit and listen.


Do we sneak an IC testing pedal onto the Wishlist


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## fig (Aug 4, 2022)

szukalski said:


> Do we sneak an IC testing pedal onto the Wishlist


As it happens…I just picked up a dozen single/dual op amp tester pcbs last week. How fortuitous!


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## mybud (Aug 4, 2022)

szukalski said:


> I have had mixed success, out of 10 3102/3207 pairs, I got 3 usable ones out of it. Again, never again and not recommended.


Yes, likewise @szukalski. In my case five 3207s from an apparently reputable eBay dealer (judging by the price and their good customer record), all of which failed to bias in chorus pedals. Replaced them with Bellings and the pedals worked fine. Now I must return the fakes to the dealer in the US and hope to get credit, so I can buy more fake chips elsewhere and return them to the dealer for credit to buy more...

It's iterative, man. Totally iterative.


fig said:


> As it happens…I just picked up a dozen single/dual op amp tester pcbs last week. How fortuitous!


No @fig, it's because you can read the universal mind.


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## szukalski (Aug 4, 2022)

mybud said:


> apparently reputable eBay dealer (judging by the price and their good customer record)


I have seen a number of bad reviews go missing from dealers of dodgy ICs.


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## mybud (Aug 4, 2022)

szukalski said:


> I have seen a number of bad reviews go missing from dealers of dodgy ICs.


Thanks, worth noting for sure.


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## finebyfine (Aug 4, 2022)

You’re doing gods work @temol


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## Diynot (Aug 4, 2022)

fig said:


> As it happens…I just picked up a dozen single/dual op amp tester pcbs last week. How fortuitous!


I smell a contest….
Thanks for the very informative graphic content Temol. Now sitting here thinking how many builds I have that contain TL072s…..


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## temol (Aug 4, 2022)

@Diynot - don't panic yet  If it sounds good than why bother? If you have suspicious ICs - just compare them with genuine stuff.


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## spi (Aug 4, 2022)

What's the source of the fakes?


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## Diynot (Aug 4, 2022)

temol said:


> @Diynot - don't panic yet  If it sounds good than why bother? If you have suspicious ICs - just compare them with genuine stuff.


That is kind of what I am telling myself at this point. Not even gonna bother cracking open all those builds


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## temol (Aug 4, 2022)

spi said:


> What's the source of the fakes?



Aliexpress. But it's quite possible that I bought some locally.


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## Guilherme Collateral (Aug 4, 2022)

THIS is how a original TL072 from Texas Instruments looks like. Anything else will be a FAKE. You can buy it for 70 cents a piece from the TI site and be 100% sure you're buying the real deal


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## Deperduci (Aug 4, 2022)

Interesting. I just have a couple 3102's that need checking, I ordered a couple extra tl072's from 1 store because they still had them for under $.75(an actual store not the 'bay) and only need them for 1 or 2 more projects I have yet to get the board. there's enough adaptor boards, SOIC-8 to pdip, I'll change to SMD for any circuit that comes out later. And just like this guy^^^ same for certain guitar companies parts, ordering direct for originals is cheaper from the actual maker.


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## fig (Aug 4, 2022)

Guilherme Collateral said:


> THIS is how a original TL072 from Texas Instruments looks like. Anything else will be a FAKE. You can buy it for 70 cents a piece from the TI site and be 100% sure you're buying the real deal
> View attachment 30304


Where’s your sense of adventure? In more rewarding areas I would imagine..


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## Guilherme Collateral (Aug 4, 2022)

fig said:


> Where’s your sense of adventure? In more rewarding areas I would imagine..


I leave it to taking bad drunk decisions


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## fig (Aug 4, 2022)

From now on, or until they run dry…I’ll get mine here…

https://www.pedalpcb.com/product/6-2-1/


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## Guilherme Collateral (Aug 4, 2022)

fig said:


> From now on, or until they run dry…I’ll get mine here…
> 
> https://www.pedalpcb.com/product/6-2-1/


Totally missed this one! Awesome


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## Deperduci (Aug 4, 2022)

https://www.amplifiedparts.com/products/op-amp-tl072-dual-low-noise-jfet-input-8-pin-dip where I got my last set and https://stompboxparts.com/semiconductors/tl072cp-dual-opamp-ic/ while he has them. my apologies to those outside the states if the per chip savings gets nuked via P&H.


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## Gordo (Aug 4, 2022)

This is interesting.  Thanks for making me more paranoid.  Actually, thanks for doing this, I had no idea that simple stuff like this is being spoofed.  Lesson learned.  I bought a metric ton of 4558 from an Amazon seller that look really dodgy but so far sound quite good.  Would be worth a test with a known good one, but apparently what's a "known good one"?


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## HamishR (Aug 4, 2022)

Guilherme Collateral said:


> THIS is how a original TL072 from Texas Instruments looks like. Anything else will be a FAKE. You can buy it for 70 cents a piece from the TI site and be 100% sure you're buying the real deal
> View attachment 30304


That's what the TL072s I bought recently from Tayda look like, but without the lovely spotless green background.  🤪

Funny that 75c seems a lot for what is arguably the heart of so many circuits when we are often ok with spending $3 per knob. And we need more of those! Lately I've been getting into aluminium knobs (insert innuendo here) and man they can get spendy.


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## Guilherme Collateral (Aug 5, 2022)

HamishR said:


> That's what the TL072s I bought recently from Tayda look like, but without the lovely spotless green background.  🤪
> 
> Funny that 75c seems a lot for what is arguably the heart of so many circuits when we are often ok with spending $3 per knob. And we need more of those! Lately I've been getting into aluminium knobs (insert innuendo here) and man they can get spendy.


I know my workbench looks disgusting, is the result of washing lots of pcb's with IPA and not taking the time to clean the workbench itself hahaha. Nice you got original ones from Tayda, the last few TL072's I got there were fakes, but the TL071's were the real deal, crazy stuff haha


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## HamishR (Aug 6, 2022)

Ha!  My workbench isn't much better! The crop tool is your friend (and mine). 

I'll have to look at some of my other TL072s to see if any are fakes. Handy to have the reference.


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## Diynot (Aug 6, 2022)

I just took a peak at the ones that I received recently (2 weeks ago) from Tayda and cosmetically they look legit.


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## Guilherme Collateral (Aug 13, 2022)

Diynot said:


> I just took a peak at the ones that I received recently (2 weeks ago) from Tayda and cosmetically they look legit.
> View attachment 30377


Awesome man, they do look legit!


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## Diynot (Aug 13, 2022)

Guilherme Collateral said:


> Awesome man, they do look legit!


Now I must do what any good guitar/pedal/amp collector must do, hold onto them forever at least until I can pop them on flea-bay for 10x the price! I’ll be rich I tell ya!


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## Crispy (Aug 15, 2022)

now im looking at all my chips i bought wondering if i got fake chips , this is just one more thing for a new builder to have to learn . the ones i have look like the legit ones but some of my pedals dont sound so great , so was i needing to blame it on fake chips now i just have my poor understanding of how this all works to blame.🤣


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