Maybe I should have been a little more clear. It is certainly loud enough. I can throw out more power than my speakers can handle.

The unit I have is the 940.

I actually had a little adventure with this.

The JVC head unit has a front AUX in and a rear J-LINK connector ( for the CD-Changer ). So I bought a JVC KS-U57 adapter and plugged it in. The adapter has a J-LINK connector on one end and a pair of RCA jacks on the other. I assumed I plugged this thing in, my Empeg to the RCA jacks and selected CD-Changer on the head unit. But I could not select CD-Changer, it acted as if nothing was plugged into the J-Link connector. Apparently on JVC head units that already have an AUX connector, you can't use this thing.
Since the AUX connector it actually on the removeable faceplace, I figured out which pins are for R,L and Ground and soldering a 1/8" stereo jack that hangs out the back of the unit.
For those interested, it's pins 2,3 and 4 if counting from the right as you are facing the front of the unit. They are labeled L CH, R CH and A GR.

I have no idea what will happen if I plug in something to the front AUX connector, but I'm not about to try it.

Now all I have to do is finish fixing all my ID3 tags and organze my playlists better.