LM3080 vs. CA 3080

chicago_mike · Post by **chicago_mike** » 22 Mar 2010, 22:47

Are these the same? More or less? I have the LM3080's and want to build a dipthonizer.

mictester · Post by **mictester** » 23 Mar 2010, 06:25

chicago_mike wrote:Are these the same? More or less? I have the LM3080's and want to build a dipthonizer.

They are exactly the same - just made by different manufacturers.

It's what's called "second sourcing". A manufacturer invents a clever IC, and designers like me put it into our products. As soon as there's an obvious market for this new device, other IC makers will start to produce functionally identical devices - sometimes reverse engineered, often with the approval of the original manufacturer, because the market for the device can only grow since it's now available from multiple sources, and more designers will start to use it....

This is why there are so many versions of the 4558. It's a really cheap (<$0.01 in quantity) dual op-amp. The JRC ones are copies of the original TI ones, and only achieved legendary status with the Boutique Boobs because they were used in some Tubescreamers. Often real A / B testing of 4558s won't show any differences between versions at all, but the Boutiquers will pay silly money for the "right" IC.

Sometimes, though, different manufacturers' ICs will have very slight differences because of manufacturing tolerances, differing IC masks and so on, even though they have the same part number. For example, I had real problems with some manufacturers' versions of the 4066 in one circuit I designed. I was muting and routing the output of tape heads, and one version of the IC had internal capacitance such that it resonated with the tape head at about 4 kHz, giving the recordings and playback a nasty, distorted sibilance that could only be cured by the replacement of the IC with another brand!

chicago_mike · Post by **chicago_mike** » 23 Mar 2010, 06:37

Coolness! Appreciate the info too.