@shamus2211Your Sanders Magtech Amp has 100kohm input impedance, a perfect candidate for a passive preamp.
You could try the Schiit Sys for only $49 and it’s returnable, it also has 2 inputs.
This should give you more transparency/dynamics and a tighter/controlled bass than what you have now.
http://schiit.com/products/sys
Cheers George