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Operational Amplifier Test Board
http://diyaudioprojects.com/Forum/viewtopic.php?f=10&t=6610
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Author:  audiophonic [ 20 Sep 2019, 14:30 ]
Post subject:  Operational Amplifier Test Board

Hi everyone i found on eBay very nice and useful OP AMP test module.
After ordering from few sources op amps i discovering that they were fake. I decided to look for a circuit that I could find and compare the performance of the original product to the product I purchased. With this board I quickly found who the counterfeit products and who original. I inserted a signal from a signal generator (100Hz to 500Khz) to the inputs of the circuit and to the output I connected to the oscilloscope and in this way I saw how for example TL074 which is currently being sold from China fake and in fact it is LM324. That's how I also saw that TL072 was actually LM358. The TL074 bandwidth easily reaches 400 kHz and the counterfeit has not exceeded 30 kHz.
Highly recommend to anyone who needs this product to check their range of server amplifiers.

https://www.ebay.com/itm/174022138071

Author:  gofar99 [ 24 Sep 2019, 20:45 ]
Post subject:  Re: Operational Amplifier Test Board

Hi, Yes indeed. I never buy such components off the Bay. ICs etc come from known good parts houses. I find that it is well worth the difference in price.

Good listening
Bruce

Author:  audiophonic [ 28 Sep 2019, 16:10 ]
Post subject:  Re: Operational Amplifier Test Board

I bought this product from the manufacturer site and it helped me a lot.

Author:  Yungman [ 03 Oct 2019, 00:23 ]
Post subject:  Re: Operational Amplifier Test Board

I always buy from Digikey and Mouser, never have problem.

Author:  audiophonic [ 06 Oct 2019, 15:31 ]
Post subject:  Re: Operational Amplifier Test Board

Digikey and Mouser They are the most trusted source of components.But for me it is now very easy to check the different performance of OP Amps I just connect a signal generator at the RCA inputs of the PCB and check with the oscilloscope a lot of parameters that interest me to adjust/find the right OP Amp for me. by the way

Author:  ILoveHiFi [ 11 Oct 2019, 17:08 ]
Post subject:  Re: Operational Amplifier Test Board

LIstening with my own ears is the most trusted source of components, one will never belive cheapest chinese to-92 transitors have best sound quality the s9014 s9015.
Compare those to 100% gneiune and other stuff like japanese transitors, especially like hot swapping with custom cirucuit and socket and single transitor gain stages.
Listneing results is that the chinese transitors sound best. Way ahead of geniune transitors in sound quality.

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