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CA3140 Problems.

Started by Bill Mountain, August 10, 2011, 02:39:55 PM

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Bill Mountain

I bought a CA3140 IC from Small Bear on a whim a little while back.  I finally got around to building something with it.  I tried making a Rat and a Blue Berry Bass Overdrive (neither of which I have built before) and I couldn't get them to work.  At first I thought that I had wired both of the pedals wrong but I'm usually able to suss out the problems.  For what ever reason I couldn't get either to make sound.  I thought maybe I just didn't understand how to use the chip.  I read the data sheet and I didn't find any special quirks.  The data sheet even says that it can replace a 741 in most applications.  With this knowledge I wired up the simple IC buffer off of Dano's site and it still didn't work.  I pulled out the CA3140, stuck in a 741 and it worked fine.  So it could either be a bum chip or I don't know how to use these.

Any thoughts?  Advice?

Thanks for reading!


Mark Hammer

They ARE static sensitive.  I can't recall ever having blown one that way since 1977 but the datasheet should indicate to be careful about static.

Bill Mountain

Well...I found the problem.  I put together a small gain stage and I got sound but it was muffled.  It sounded like the voltage was too low.  I measured my supply and I only got 3V!  I hooked up a 9V battery and it worked fine.  I guess I need a new power supply!

Thanks for your help!