Newbie here, been browsing the forum for quite some time and went to order my first DIY-amps some two weeks ago. Because of all the positive feedback on the AMP6 and my project being a Festival-Boombox, i decided to go for that one.
Been some years at Roskilde Festival with the same DIY boombox, sporting many different amp-setups, since the amps tends to get stolen every single year (poor concealing of the box i guess). I´ve ran a T-amp before, some chinese TA2020 pre-assembled product, that my friend got of eBay and we were very satisfied with it. Especially the battery life you get from it. Of course, that one got nicked to. This year i will, as mentioned, go with the AMP6B for the box. Ordered 3(!), one for myself, one for my girlfriends box and one spare. Have assembled two of them as of now, and im having some trouble with both.
So here goes the troubleshooting.
Soldered the first one extremly thorough in accordance with the assembly info given on 41hz.com. At first I got the rapid clicking noise, redid some solders and i eventuelly, without to much hazzle, got music from the speaker. After a track or two, the amp would go back to rapid clicking and the chip became very hot (to hot to touch). After a few minutes the amp would play again. I hooked it up to my boombox (2 x 2 p.audio 8ohms in parallel with 2 x 2 piezos paralleled as well. Ill upload the schematics if that would be any help to you guys) went outside and played for some time with the amp getting only moderatly hot, maybe because of better circulation outside. No problems there.
Some days later as i powered up, the amp was back to rapid clicking. I started troubleshootin earlier today and now it doesnt even click. There is no outpu to the speakers whatsoever.
The chip still gets hot
Ive got approx 5V over C2
approx 1.2V over R7
only have about 100 - 120 mV over C5 (should be around 10V)
I run a 12V 60Ah car battery as power supply, somewhat new and recently charged
low output on J10
I have some knowlede in schematics and datasheets, and used these a bit in troubleshooting, and as far as i can see, my the only "wrong" is the voltage over C5.
Heres some pictures of the pcb
EDIT: Pictures in full resolution:
I apologize for the long description, I hope you guys will share some of your wisdom in what my next move is. Any help would be greatly appreciated.
Im sure i missed some important in my description. Please let me know if you need more info to tell what is wrong.