> Hello All,
>
> Hopefully someone on this list has some experience with the ISD audio recordin
g/playback chips. If so, has anyone been successful recording to one of these ch
ips directly using the headphone output f>
> The circuit example that come with the datasheet for the 1400 series shows a m
icrophone input, though it also says that "...if the desired input is derived fr
om a source other than a microphone, the >
> Following this advice, I've hooked up the negative headphone output from the s
tereo to the circuit ground, and have the positive signal going through a .1uF c
apacitor and 100K pot (in series) to the >
> Does anyone see anything wrong with this setup? BTW, since I'm not using a mic
rophone for input, I don't have anything connected to the MIC, MIC REF, or ANA O
UT pins, nor do I have anything connected>
> Any advice (or a pointer to a working circuit diagram) would be greatly apprec
iated!
>
> Thanks,
> Mark

 Mark,

I am using an ISD1416 to record the output from an 8 ohm speaker. I
finally had to use an 8 ohm to 1k isolation transformer between the
speaker and the two MIC inputs to get rid of the hum. I tried a
single ended input first without success. Going to a balanced
input, isolated from ground, cured the problem. I did not try the ANA
IN pin as I wanted to retain the filtering characteristics of the
coupling network.

Hope this helps.

Bill,  W3NMK