Problem with tube preamp - any help...

Was going to introduce a DAC today for fun (never tried one) and just prior I turned everything on just to listen for a while before the trial. All I get is very low volume from my source (both cdp and tape) and the Rogue 66 preamp allows the signal to come through regardless which component I choose on the selector. I can hear the cd I am playing on "tuner, aux 1, aux 2 - you get the picture -even though its only plugged into the cd inputs... Same goes for tape... and its both channels - same low volume on both sides. As I have never owned tube gear in the past and have yet to "tube roll" might the problem be the linestage tubes??? The volume doesn't work (won't get louder) nor does the mute button. Tubes or malfunctioning preamp - your opinions are most welcome
I'm assuming you changed nothing..?? (since the last time you listened) Check inside for a fuse?--Double check: source in / mains out. All I can think of for now.
Perhaps a tape monitor switch, though this would not explain the low level leakage.
The mute button on the Rogue 66 does not completely cut the signal, it only drops it 20dB or so, and you can still hear music if you turn up the volume, which then amplifies the crosstalk to audible levels. Turn the volume down, then make sure the mute button it is in the out (off) position. Double check that all connections in the back are correct.
Turn down the volume, turn off the mute switch. Check all connections. Enjoy!