I recently build my second DIY amp (the first one was simple TDA2030 hifi amp on 9V), using design Little Gem Mk1. I hooked it up to my Peavey's Rage 258 speaker (8ohm), a fresh 9V and my guitar. The amp was producing good sound for about 1-2 sec. Then it died. LM386 was buring hot, so I disconnected the battery quickly to avoid damaging the IC, but I fear it could have died.
I took my time and built the amp very carefully, checked the solders with a multimeter. The only differences are that I didn't connect the gain pot, and master vol pot (hard to get in my area). The gain pot isn't necessary for the amp to run according to the instruction. I thought the master vol pot isn't necessary (it should pass full power to the speaker when at certain setting right? ) so i skipped it and hooked speaker to - of 220u cap, and ground, does this cause the problem, or something else ? Too low speaker impedance ? Bad IC ? I guess in few places my soldering skill could be lousy, but I don't think it did cause the problem.
Link to the design, just in case
http://www.runoffgroove.com/littlegem.html
I took my time and built the amp very carefully, checked the solders with a multimeter. The only differences are that I didn't connect the gain pot, and master vol pot (hard to get in my area). The gain pot isn't necessary for the amp to run according to the instruction. I thought the master vol pot isn't necessary (it should pass full power to the speaker when at certain setting right? ) so i skipped it and hooked speaker to - of 220u cap, and ground, does this cause the problem, or something else ? Too low speaker impedance ? Bad IC ? I guess in few places my soldering skill could be lousy, but I don't think it did cause the problem.
Link to the design, just in case
http://www.runoffgroove.com/littlegem.html