TL072 vs "TL072"

temol

temol

Well-known member
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

1659601547172.png 1659601571961.png

and LM358 for a comparison.
1659601606387.png


Here some oscilloscope images from a working circuit.

1659601725168.png 1659601761363.png

1659601799588.png 1659601782735.png
1659601929506.png

1659602095753.png

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.
 
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.

Simple setup, one inverting stage.

Genuine vs fake

View attachment 30281View attachment 30282

and LM358 for a comparison.
View attachment 30283


Here some oscilloscope images from a working circuit.

View attachment 30284View attachment 30285

View attachment 30287View attachment 30286
View attachment 30288

View attachment 30290

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

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..
Click to expand...
Yes indeed, don't mention BBD chips. Oops, sorry, I just did, didn't I?
 
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.
 
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.
Click to expand...
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!
Click to expand...
No @fig, it's because you can read the universal mind.
 
fig said:
As it happens…I just picked up a dozen single/dual op amp tester pcbs last week. How fortuitous!
Click to expand...
I smell a contest….
Thanks for the very informative graphic content Temol. Now sitting here thinking how many builds I have that contain TL072s…..
 
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.
 
You must log in or register to reply here.
Back
Top