Solid State Guitar Amp Forum | DIY Guitar Amplifiers
Solid State Amplifiers => The Newcomer's Forum => Topic started by: Aeroplane on May 28, 2016, 08:02:17 AM
Hi Folks!
I'm a electrical engineer (more on the building/power side than audio/micro/signals though) and I got an electric guitar a couple years ago. I thought that building my own amp would be a great project, so I decided to start small, with an LM386-based amp. I followed the basic schematics used by the following links: http://www.electrosmash.com/noisy-cricket-analysis (http://www.electrosmash.com/noisy-cricket-analysis)
http://diystrat.blogspot.com/2014/03/building-noisy-cricket-mk-ii-and-mini.html (http://diystrat.blogspot.com/2014/03/building-noisy-cricket-mk-ii-and-mini.html)
I ordered parts, dug out my old breadboard from college, threw it together, and promptly ran into a wall.
When I plug in my guitar and hook it up to a bookshelf speaker (or headphones), it occassionally makes some buzzing sounds, but that's about it. I'm afraid that the LM386 chip I bought (off ebay) might be a counterfeit. Or my 9V battery might not be up to snuff. If anybody has any general tips, I'd appreciate it, because otherwise I'm stumped for while. Thanks!
The most basic piece of test equipment is a digital Volt meter (DVM). You can usually find cheap ones for around $10 USD. Sometimes at Harbor Freight they give them away if you buy something else, even a pack of 9V batteries.
If you do have a digital multimeter you can of course check if battery measures around 9v (but if it's not 100 years old then it shouldn't really be a problem, as this circuit should work with supply voltage as low as 4-5v I suppose). If it does (and if you have any other audio amp) then I'd advise setting up a simple audioprobe (you can read about it here (http://www.diystompboxes.com/pedals/debug.html)) and probing through the circuit starting from the input. If you do get the signal up to pin 2 but not on pint 5 of lm386 and pins 6/4 are connected to +9v/GND, then there is a chance that your chip is dead.
But the easiest way to troubleshoot would be to provide us with some pictures of your build :dbtu: