Help Find an Op-Amp for Popular Electronics Project

[uchimata]

Hey everyone,

Whelp, I've had this project dancing around in the back of my mind for a good six months now and I'm here to ask for some help. I'd like to build this biofeedback device from an old issue of Popular Electronics:
http://72.52.208.92/~gbpprorg/mil/mindcontrol/Build_A_Brain_Wave_Feedback_Monitor.pdf

The problem I'm running into is that the op-amps (Signetics N5556) are old and just about impossible to find. I've checked all of the electronics outlets I can think of for them, and the other parts were easy enough to source. Does anyone have a link to a shop that would carry something obscure like this? Barring that, could anyone suggest a substitute that's readily available?

I'm just a hobbyist that enjoys building weird things so I apologize if this is a goofy question. Any expert advice would be GREATLY appreciated. Thank you!

 

[Jony130]

Simply use TL071 instead of N5556.

 

[Mike_In_Plano]

There are many choices that would likely work, because this was a fairly crude technology. The TL071 is probably good. Otherwise, I'd suggest an OPA277, which has fairly close characteristics and is based upon the same technology.

 

[schip666!]

Might I suggest replacing the input section with one of these:
www.analog.com/static/imported-files/data_sheets/AD620.pdf
which is made for doing the kind of thing that brainwaves need. It will have much better common mode rejection and such like.

 

[alphysicist]

Hello,

Thank you for reaching out for help with your project. It sounds like you have a really interesting idea in mind and I'm happy to assist you in finding a suitable op-amp for your biofeedback device.

Unfortunately, the Signetics N5556 is indeed an older and less commonly used op-amp, making it difficult to find. However, there are several options available that may work as substitutes for your project. Some suggestions include the LM741, TL071, or LM358 op-amps. These are all commonly used in audio and signal processing applications and should be readily available at most electronics outlets.

I would also recommend checking online retailers and auction sites for the Signetics N5556. While they may not be readily available in physical stores, you may be able to find them online from a seller who specializes in vintage or hard-to-find electronic components.

Lastly, I would suggest reaching out to other hobbyists or electronics enthusiasts who may have experience with this project or a similar one. They may be able to offer additional insight or suggestions for suitable op-amps to use.

I wish you the best of luck with your project and I hope you are able to find a suitable op-amp to complete it. Let me know if you have any further questions or need any additional assistance.

Best,