Issues about the lm386 audio amplifier

[millionreason]

Hi, I'm new here. I'm trying to build a simple LM386-based audio amplifier circuit.(Here's the details of LM386:http://www.kynix.com/Detail/274538/LM386.html )
See the schematic of what I've got.



I've got a simple pair of earbuds plugged into the audio output end, and an FM radio plugged into the input end for testing purposes. I'm powering it off of a 9V battery.

What I hear through the earbuds is a "click" at regular intervals. Listening closely, I can tell the "click" is actually a very short snippet of audio from the FM radio. (Just a single note or even less.)

Again, I'm pretty new to this. Please don't hesitate to point out anything bone-headed I'm doing. All help is greatly appreciated!

Thanks in advance.

[Dave Cawley]

You may need a DC blocking input capacitor, and a DC path at the input to the amp chip, although it may work without that.

Dave

[Doctor_Electron]

I built two LM386 amps on a lab breadboard back in 1977. Input was a Dynaco FM-3 tuner, output to Koss Pro-4AA. The schematic was right out of the 1976 National Semiconductor Linear IC book. But I think I used + and - DC power rails ( a bunch of GI issue size "C" carbon-zincs soldered together ).

Sounded great. I put the little system together because I was working at a USAF radar station high up on Tranquillion Ridge on Vandenberg AFB and even on the old Dyna I received tons of FM stations, San Diego to San Francisco and beyond. Back then some of them actually transmitted with some degree of audio quality. The Jazz station out of UC Northridge was stunning. Antenna was a $ 12 rat shack FM turnstyle mounted in a small unused radome on the roof. I miss being in and DXing from up on in those mountains, but of course I couldn't get on the Base now without being shot (or worse) !

Check out a copy of the National Linear applications book. And if the circuit I used was indeed bipolar powered the parts count for each channel is smaller.