[joeyliao]

i have finished my first cmoy breadboard layout, but the only op amps that i could find locally are NE5534N made by philips electronics.

i have looked at the datasheets, but dont really know what parameters to compare with the original TI chip. does anyone know if these chips are the same/similar in function/specs?

or is the numerical designation between the philips and TI product a coincidence?

same question on the elantec EL2227/8C op amp vs the burr-brown OPA2227/8. what is the similarity, if any, between the products from the different makers?

btw, the breadboard circuit works, but the output sound level is very low. i think i will wait until i get my shipment of OPA2134 before i do any more fiddling.

 

[paulb]

Actually the original was made by Signetics. Philips might be the same company.
I think TI buys the dies from Philips or whomever and puts them in their own package.
Look at the data sheet carefully, I think the NE5534 may not be stable at unity gain, and even with a small gain you might have to add a capacitor for compensation.

 

[mlloyd1]

Yes, the NE5534 is NOT unity gain stable. You will have to compensate it when used in applications where the gain is too low.

 

[Daniel Pumphrey]

Part Numbers from manufacturers can and are often the same but they are never the Same parts. Do not trust these numbers from Manufacturer to Manufacturer. Many companies use the term OPA as a prefix for an Opamp too. Some manufacturers use the same number for two or more totally different parts. Once a part is discontinued it's number can and often is reassigned to something completely different later for future generations.
Stick with the manufacturer recommended for any particular part and you will usually be safe.
Some older parts can be cross-referenced and also some well known designs are made by several different companies after the original patents expired. An example is the 3904 and 3906 transistor which is still used today for certain applications. They can be bought from many different manufacturers and I try to stick with well known companies like Phillips, Motorola etc for parts such as these.
Many of the parts we use are designed by Burr Brown, but are made in several different countries where labor is cheap. So things can get confusing really quick. Putting the wrong chip in can be catastrophic so be careful.
Dan

 

[Apheared]

Well, that's not entirely true. Sometimes a part is also made by someone else, later in life. But usually the entire part # will be the same, even if it's not their normal nomenclature.

Like, many people make LM317-Ts, not just National. Philips uses TDA* for it's amp chips, but you can get TDA2040s from ST...

I wish it were simple, but you'll have to dive in... or ask everytime you come across something you want to get. (in your case the NE5534 is probably actually better than the original, but the e'lantec and b-b chips are entirely different animals)

 

[joeyliao]

thanks everyone for you opinions and info.

i couldnt figure out what to do with the NE5534N from philips even though i read the datasheet. (not an engineer!)

so i just waited for my BB OPA2134s to arrive. and arrive they did. i threw together a breadboard amp based on one of the schematics posted. it wasnt the basic cmoy, but the one used by the hansen board.

i didnt build the crossfeed, just the two gain stages. plugged it into one 9v batt and then to my md player. the thing works and sounds great! (yes my first amp, got the virgin excitment thing going)

hope everything translates well to the perf board.

still waiting for some parts, but will post pictures when done (as seems to be tradition).

thanks again for your comments on this thread and others, i already have orders in for other chips as i plan to do alot of building and experimenting!

joey