Thanks for your replies.

I'm using the latest firmware (1.25) and I'm not using gain control.

I found posts on the riovolution forum that seem similar to my problem and recently replied there (so it should be near the top of the karma forum)

The click is faint and fairly rare, but it does happen more or less consistently. I've been listening to the same song over and over and the click happens every once in awhile but not every time the song is played. Maybe every other time or slightly more frequently.

The song is encoded with lame, using the --alt-preset standard setting.

I'm trying the pause test now and haven't heard a click.

-Neal