Hello,
I came across the following problem which I would like to solve with your help. My brand new iRiver iFP899 provides a stereo line-in jack for connection to any kind of source providing line-in level for direct encoding. It can also be used as external mic input via settings in the menu of the player. I guess the jack input features so-called "plug-in power" which means that a few volts of bias on the mic input is injected, which can power some small consumer-type electret mics that don't have their own battery (although most do have batteries anyway). I measured the input and it provides about 3.15V (DC unloaded) for bias voltage. Funny enough, the bias voltage does not dissappear when I switch to "line-in" mode from "external mic" mode. Now I want to connect my hifi mixer to the device to record old vinyl records, CDs, whole real-time mixes etc. As soon as I plug the device into the mixer line-out output the VU meters overflow, i.e. they show full amplitude. I guess that is due to the "wrong direction" current travelling INTO but not OUT OF the mixer because of the bias voltage on the wire. What tricks can I use to couple the device to my mixer so the iRiver line-input DC bias does not reach the external source and does not affect it?
Many thanks in advance and best regards
Quinn