Author Topic: Can Dave make a video comparing EBAY OP-AMPS to real ones  (Read 2703 times)

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Offline MathWizardTopic starter

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Re: Can Dave make a video comparing EBAY OP-AMPS to real ones
« Reply #25 on: April 07, 2023, 07:19:35 pm »
You are also paying for someone to pick the part up off a shelf pop it into an esd bag and seal/label it. The cost of doing this along with business expenses are getting increasingly more expensive.

Avoid buying rubbish from china it only encourages them to make more fakes. What is annoying here is the local electronics retail stores are all filled with chinese rubbish as well. I'd rather pull something off an old board than pay for a no name or generic component.
I'd pay a $1 for a chocolate bar, and that's gone in seconds, so IDK what I'd charge if I was making them. But I wish the makers, sold directly to small users (for cheap). A machine would just be put at the end of some lines to pack and ship it.


 In the way of op-amps, from Mouser and LCSC got some real T.I. TL082's, LM324's, TL084's, LM339's

From LCCS I also got some lesser brand-name chips, since I already had too many things I wanted. So I got
OP-07
https://datasheet.lcsc.com/lcsc/2203081630_HANSCHIP-semiconductor-OP07CDRG_C2977079.pdf
vs the analog version
https://www.analog.com/media/en/technical-documentation/data-sheets/op07.pdf

TL084 copies
https://datasheet.lcsc.com/lcsc/2301061709_Gcore-TL084_C5157168.pdf

COS77DT
https://datasheet.lcsc.com/lcsc/2006301914_COSINE-COS77DT_C693069.pdf
vs the Analog.D version
https://www.analog.com/media/en/technical-documentation/data-sheets/op77.pdf

COS227
https://datasheet.lcsc.com/lcsc/2205051816_COSINE-COS227USR_C3008541.pdf
vs the TI version
https://www.ti.com/lit/ds/sbos079c/sbos079c.pdf?ts=1680865811685

Besides a few audio amp-amps I have, all the rest are jelly bean, so the above should be a nice step up in some circuits.

Most of these were SMD tho, so it will make breadboarding and proto-boarding an extra hassle, and maybe add more offsets.

I haven't tested any of the new ones yet. In LTspice I was trying some op-amp test circuit's, and some of the test circuits weren't sensitive enough for say a LT1013's offset voltage. I haven't made any IRL yet.
 

Offline Mechatrommer

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Re: Can Dave make a video comparing EBAY OP-AMPS to real ones
« Reply #26 on: April 07, 2023, 09:37:20 pm »
you take care your own. for tight arse like us hobbiest who doesnt want to spend much but expect acceptable performance for a particular project, make your own opamp performance test rig and specify and document your own stock, attach is example from my test pcb for 2 opamp ic. as dave said, its a lot of work, even on a particular opamp type has different clones and performance. attached later is my 3 different 5532 clones performance capture bought from different sellers, i also have rail to rail clone opamps specified, so i know their limitation and know if they are suitable for a project or not. the good thing is all clones that i bough advertised as rail to rail are indeed rail to rail, unlike the non rail to rail clone jellybean version, thats all i care. for pro, dont buy clone, you chap dont care about money so you can order from digikey, ymmv.
Nature: Evolution and the Illusion of Randomness (Stephen L. Talbott): Its now indisputable that... organisms “expertise” contextualizes its genome, and its nonsense to say that these powers are under the control of the genome being contextualized - Barbara McClintock
 


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