I have been working with the 3204 with a single ended mike input and an 8ksps sample rate. As I have seen on the forum, I am not alone with a fairly high level rushing sound coming through with the data. This is killing the low end dynamic range, and therefore the microphone sensitivity. I am running minimal gain on the PGA, and I have tried all of the suggested fixes put forth on the forum. Lots of bypassing of the analog supplies and careful routing of analog grounds. No changes on the output noise level. The level does rise and fall with the PGA gain, but, even at 3 or 4 dB of gain, it seem excessively high
Next, I removed the mike to see if it was the source, then I disconnected the mike bias from the input. No change. I have previously worked with the AIC26, and I know what the noise level should be, so, what am I missing??
Thanks, Ron