You probably know this, but unless there's a practical or convenience reason you don't necessarily need an HT passthrough. You can use any line level input on any preamp and just establish a "reference" volume level on the preamp when you set your HT levels. I used to use the 12:00 position to make it easy.
Obviously the benfit of this is that you can choose from any preamp available rather than just limiting yourself to preamps with the passthrough feature. Best of luck.
Obviously the benfit of this is that you can choose from any preamp available rather than just limiting yourself to preamps with the passthrough feature. Best of luck.