The Old Logo LM1875 National Semiconductor

As you can see from my previous post and far before I create this blog, I have built many Gainclone amplifier using either LM3875, LM1875 or LM3886. The sound characteristic from each IC is all different. Let take the example LM3875 or LM3886 that perform more dynamic and open sound stage. Those IC's are also the latest production comparing with the LM1875. Speaking about the LM1875, this is the ancient IC from National Semiconductor. This LM1875 sound characteristic are so much different with its brother. It sound more warm and mid-centric amplifier. I also aware that this LM1875 is one of favorite IC. It has been around very long time before this Gainclone amplifier become popular like today.

If I took the different production batch of this LM1875, I found different characteristic especially between the old production and the newer one. This is very interesting and I will talk about it in this post.

The LM1875 on the picture above is the first National Semiconductor with the double N logo. The logo like a thunder storm. It sound better compares to the LM1875 with the new logo. What is the better term I mention above? The sound is more open on the mid-range.

The reason for this maybe I should share my friend story. He used to work in this semi-conductor industries, the National Semiconductor. He is in charge for the production line department. One major raw material for production the semiconductor is the pure gold wire. This very tiny gold wire is major parts to making the IC like this. Sometimes it get stolen by the employees by take it little by little to their own pocket. Many ways are tried to implement by the manufacture to prevent this happened. One of them is put the gold sensor in every access door to the factory and it is works.

Like this old National Semiconductor logo, this could be production before the economic recession. As we are can assume, the global economic recession drives the manufacturer to do cut cost in every corner. I think it also happened to the raw material as well. The pure gold contain is probably less in the newer production line?

Okay I am not quite sure about it.

It is just my theory after I talked to my friend about this issue.

But the real things is the sound quality are different between the newer and the old logo. You can try this if you have a chance to get one of those.

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