SQ - AV processor preouts vs. stereo linestage preamp

i have run the processor preouts into a preamp and found i need to turn up the preamp sound all the way to get sound to come thru from the processor.

You can control that by increasing the level of the L/R channels in the prepro’s level balance that would allow you to not have to turn the stereo preamp’s volume level up high.  Or, as you say, if you get a preamp with a HT bypass it becomes a non issue. 

wish i never learned about stereo pre’s - ignorance is bliss.

But crappy sound isn’t. 

How do u use avr preouts.

Just run a pair of interconnects from the front L/R preouts of the NAD to an unused input (or HT Bypass if there is one) on the stereo preamp.  You can continue to use the NAD for HT duties, but it’ll be completely out of the signal path for 2-channel, which is what you want.  Best of both worlds in one system. 

Not if you connect the AVP’s preouts to a good stereo preamp.  The only way to go IMO.