Audio Circuit Problems

Original Black or Red Sharp Twin Famicoms with serial numbers under around 400,000 may have resistors R103 and R104 swapped. These are part of the FDS audio circuit and it is not a pleasant sound when they are swapped. Sharp fixed it fairly quickly, but I don't have an exact serial number cutoff. I have seen a few just under 400,000 that were swapped, and a few over 400,000 that were fixed, so the change is somewhere around there. I have never seen a turbo model with them swapped.

They should be as follows:

R103 = 2M2 (Red-Red-Green-Gold)

R104 = 1M2 (Brown-Red-Green-Gold)

All models have R125 as 22K. This affects Audio 1 from the CPU which is the output for the 2 pulse channels. The original Famicom uses 20K in this position. Personally I don't really notice much of a difference with this one.