Author Archives: Jim

Here’s the small board that will implement the extra output amplifier to have the black prototype recording preamp/AGC/limiter thing put out enough that it works with the iRiver T30 recorder without the dumb empty files. I did go with the … Continue reading →

I may have been wrong about not being able to put an output stage in the prototype recording preamp before the weekend coming up Feb 18-20 in Washington DC. While I don’t have time to redo the whole board, including … Continue reading →

The problem all along has been that the output of the preamp/AGC/limiter chip was clipping – being overdriven.  Now in a reasonable chip whose job is to prevent distortion, we would really hope the designers wouldn’t overdrive the amplifier on … Continue reading →

All I wanted to do was make some quantitative tests on the breadboarded AGC chip.  I don’t have any calibrated audio equipment, so I thought it would be nice to have one calibrated attenuator.  Nothing fancy – just a pot … Continue reading →

The good news is that I did much better at aligning the replacement chip on the header than the original.  (That was after I blew out the first one by exceeding the absolute max supply voltage.)  It seems to distort … Continue reading →

I built a new preamp/limiter from a 3V SSM2167 (with 0.5mm pin pitch) quite a few months ago.  I did a little bench testing and could hear its AGC kicking in, and though it didn’t seem as good as the … Continue reading →