Salas got around building new offset ic today. Plugged it in with inputs shorted and meters on output. Got meters pegged when I turned it on. Pulled the ic. Turned back on to warm up and zero back out then install ic. Covered with towel to block drafts then went to eat supper. When I returned left channel fuses were blown. Replaced fuses. Got + and- 17 volts output on dcbs. But I have no dc offset in that channel on dcg3. Even when I adjust the pot. What happened and how do I go forward? Thanks mark
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Confirm pin 1 with continuity buzzer. If correct, the SMD chip can be also killed during soldering due to overheating or static.
Incidentally I was at katopis today where he happily demoed OPA2156 and OPA1642 to me installed in his balanced build. Two chips at a time. He bought them assembled from a guy on eBay. He was swapping them without adjustments. Only by powering down. 0.000V offset in all goes. He was very excited with doing such chips comparisons.
Incidentally I was at katopis today where he happily demoed OPA2156 and OPA1642 to me installed in his balanced build. Two chips at a time. He bought them assembled from a guy on eBay. He was swapping them without adjustments. Only by powering down. 0.000V offset in all goes. He was very excited with doing such chips comparisons.
I think I can also now see a part of "2" mark near there. Sadly something went wrong for a reason. As for the chip itself it can be blown off with hot air gun and reinstalled.
Yes pin 1 is the square for socket orientation, but the traces rotate 90 to opamp orientation which is why they give you the registration dot on the top. notch, detent, line, depending on opamp abuts/orients to dot. Point is there's no directly aligning the notch, detent, line on opamp with pin 1 on the board—that's just for knowing orientation in the socket.