Whick brand is this LM318N?

[rmgvs]

Who knows what brand/make this LM318N is? Initially I thought it was one from National Semiconductors. But in the mean time I have ordered LM318N's of this brand but these have another logo on it.

[wahab]

seems it s a NS...

[BrianDonegan]

Definitely National Semiconductor

[peranders]

National Semiconductor designed this opamp but Texas, Linear Technology, Unisonic Technology and possibly others manufature it.

Notice that this opamp is vintage and you have lot's of more modern ones in the market.

[rmgvs]

Thanks for that. Then it's clear it is a NS. Possibly they used different logo's over the years.

I also have LM318P from Texas Instruments. What is the difference between N and P versions? I changed them in the circuit and they work allright (technically the same). The P version though (from TI) seems to 'sound' worse to my ears than the NS N-version (well, let's put it in this way: I think I can hear the difference between the two).

[richie00boy]

N is just to show it is NS version, P is to show it is TI version. Most makers add their own letter onto the end to help identify.

[tomchr]

The two wiggly lines in the first line is the old National Semiconductor logo. The company switched to the new rounded N logo in the mid 1990'ies (done by the CEO just before Brian Halla - I forget his name). The M after the logo is a code for the manufacturing plant and 8930 means that the chip was produced in 1989, week 30 (late July/early August).

And your second question: Different manufacturers add different suffixes to their part numbers. For the same part number, same manufacturer, different suffixes generally indicate different performance grades. This was done a lot up through the 80'ies and maybe 90'ies when parts were sorted according to performance and given different grades. Lately, the trend seems to be to minimize part-to-part variation through tight control of the manufacturing process. This wasn't an option earlier as the manufacturing processes hadn't developed enough. These days - at least for NSC - there seems to be one performance grade (high performance) and the suffixes are used to indicate which package the chip is mounted into.

~Tom

[tvrgeek]

Yup, National. But it does beg the question, who cares? Sure, 20 years ago it was a hot part, being rather quick for it's day.

[rmgvs]

Well, thanks again, I learned a lot about the suffixes and logo's and that's what was my question about.

Off topic maybe: I am surprised by how easy old is done away with 'worse'. In the course of building a preamp I have in stock a large number of different IC's from different brands. I just plug them in (assuming they are compatible) and listen to it for a few days. Modern so-called audiophile (expensive) opamps from Burr-Brown, AD etc sound more fresh, quicker maybe but not better per se. For some reason I like the sound of the better LM318 in this particular circuit, it sounds almost valve-like to me (but with better bass and drive). And I see another topic about some variant of gainclone which also uses LM318 as input-stage just for this reason. Subjective? Sure! But it's me who has to live with it, and to decide which one goes in and out.

[rmgvs]

I mean these quotes from the LM3886 topic:


The LM318 choice it's extremely determinant (for my). I have tested various OP-amp (NE5534, OP27, TL081, TL071 ecc...), but the audio performance (compareted a class A amplifier) are superior.
An other motivation is that the slew-rate of this OPAMP is suited to this application (or all final amplifier device )

And:

To depart the final audio evaluation ( I love LM318 "valve" sound ),
has to consider a suitable high frequency gain margin, and phase, to maintain
stable all. This circuit is the result of a serious long of experiments, among the like some on
techniques of feedforward one's own about to this OPamp (not used).