The Fostex PC-1 is a passive volume control and has a 3.5 mm jack input to which iPods, PCs and other signal sources can be easily connected. Active speakers or power amplifiers are simply connected to the RCA output of the PC-1.

I have been blown away by the quality of the Fostex volume controller. I needed it to attenuate the output of a mixing desk during live shows from my ZOOM h2n recorder as the line level in isn't actually line level. This little unit has cured the issue and there is zero effect on the actual quality of the sound. In fact... by adding a slight bit of headroom I am able to master the mixes in Ableton before uploading so the quality of my live recordings has increased.
very happy customer!