I adore my Khozmo passive (with remote option and all the resistor upgrades). It displaced my Slagle AVC.A good potentiometer will always sound less colored and more dynamic than the transformer based based passive.
Here is another good one for the OP fast around $500
https://www.goldpt.com/sa2.html
Or the 4 input stereo or dual mono https://www.goldpt.com/sa4.html
Cheers George