Lefty is correct. To use the phono section of a T8+ alone, come out the tape outputs of the preamp with its selector switch set to the Line 1, or Special position. Turn the volume control all the way down.
You will now get the direct output of the T8+ phono section sent on to another preamplifier if that is what you desire.
Note that you can use the tuner section of any old FM/AM stereo receiver as a tuner alone using the same technique. Connect its tape outputs to a spare set of line level inputs on your preamplifier and don't bother with the receiver's speaker wire connections at all.
No problem running any AVA preamp with nothing connected to the audio output jacks. All are totally stable in this mode of use, as are all AVA power amps too.
Of course turn the preamp and or power amp off while connecting or disconnecting audio cables. Not doing so risks generating large possibly system damaging transients.
Frank Van Alstine