Reply 100 of 113, by keenerb
keenerb wrote on 2021-03-26, 03:55:
OK so it IS working, it's just EXTRAORDINARILY quiet compared to the Pearce board. I pulled the PIC completely and I can barely hear the default SN76489 noise and music playing with speakers turned all the way up, which is ear-splitting when using the Pearce board. Maybe the variable resistor thingy is the wrong type, or the LM386 amp is bad?
I have swapped the LM386 with a new part, swapped the SN76489 with another known-good part, and triple-checked the resistors and capacitors against the parts list provided.
OK I figured it out. The headphone jack provided with the kit was missing the ground lead, I don't know if it's the wrong part or defective part; I don't see how I could have accidentally removed it, it's missing the leads from inside the headphone jack as well.
I replaced and it seems to be working perfectly now.