jessbussert

Following that logic, if I shorted pins 1-8 the output would be the greatest? On a lark, I tried this. The gain is ok but not great. Can you suggest a mod that could bump low volume signals significantly while clipping high volume signals such as when you bump the stethoscope against the table? Am I asking for too much? Thanks, Jessica

When I pull the mic, I still get the crackle. At first, there is no noise. Then, after about 3 seconds, the crackle slowly starts back up. When I pull the pot and/or U1, I get nothing whatsoever. When I assemble this for the final, I was probably gonna build it dead-bug style just to compact the size as much as possible. After, I'd probably dip it in epoxy to seal everything up nice and tight. Any problems with building it like this? The 10uf cap that you proposed above, if I increase or decrease that component, will I get more amplitude still? Which direction do I want to go? Thanks, Jessica

Yeah, I've used muriatic acid and hydrogen peroxide with very good results previously. Check out: http://www.instructables.com/id/EFVWDTSLWYEV2Z8QB1/ for details. You want to do this outside or in a well ventilated shed or garage. Don't spill it as this is also nasty stuff that will eat a hole in your floor or in your skin... That said, it's cheap and it works great. Jessica

I had the chance to try your proposed fix last night. Unfortunately, the addition of the cap only produced a crackly buzz and no other audio. When I removed the cap, the quiet operation from before resumed. Any ideas? (I hope I'm not doing something stupid here...) Thanks, Jessica

Hi folks, I'm a half deaf nursing student with a smidgen of electronics knowledge. I just breadboarded Audioguru's Electronic Stethoscope project and am having a few problems with it. I originally found the schematic here: http://www.aaroncake.net/forum/topic.asp?TOPIC_ID=5923 My problem is that, while I'm getting output, the gain is far too low to be usable. I've rechecked my connections and components and am pretty sure I've got things all in the right places. I originally questioned whether or not I was using the right kind of mic, but I think I've answered that question as well. Can anyone look over the schematic and suggest components that I can replace in order to boost the gain? Or, alternatively, offer some points on the circuit to test for voltages, resistances, and whatnot to help confirm that I've built the thing properly? Thanks in advance for the help! Jessica