cd plays without preamp

Tom, I appreciate that.

Now that sounds weird, The Outter Limits or The Twighlight Zone weird.

Will this still occur with the preamp unplugged?

...Maybe something wrong with the power switch?

Are there tone controls on your preamp, or a method of selecting different sources? If there are and these work then I would agree that perhaps the unit is actually on. If not (and you could always just unplug to to eliminate that possibility) without looking at the schematic it would be impossible to say for sure - but - it is likely that your volume control is a potentiometer and you are feeding the signal through the rest of the passive components (resistors, coupling caps, feedback resistors). I would be curious to know if the volume is roughly what it was when the unit was obviously on, for the same position of the volume control.

There are tone controls on the preamp, more importantly the speakers get wired to the preamp, which I use for switching different sets of speakers in different rooms ( i.e. A speakers or B speakers along with A+B). This I coud understand the signals ran through the preamp, but how I could use the volume and tone controls at the same time with it turned off. I did not try unplugging the preamp because I now have my new preamp set up ( which does not have speakers wires to it as the Dynaco did ). I will have to go back and re- do everything to check if in fact the same thing will happen with the preamp unplugged. The volume control was definately in the same postion for the same volume as if it were turned on.