Quality pre amps with home theater by-pass

The Audio Research line stages of the last twenty or so years have processor pass-through inputs.

Krell KRC HR.

I think VAC includes HT bypass in at least some of its preamps if not all. I'm sure you know this, but it's very easy to establish a reference volume level with a pre that doesn't have a bypass (I just set mine at 12:00 to make it easy). Would open up a lot more options for you. Just a thought, and best of luck.

I think Allnic now offers home theater bypass.

I have a Parasound JC-2 BP. You can configure any of it's 6 inputs as a home theater bypass (or more than one). That also includes the XLR inputs. This is only on the BP (bypass) version and is $500 option.
Ben

I used to set up like this with my ARC pre. But thought it was a waste of premium Amperex 6922 white label PQs for watching movies, so I completely separated the two systems.

FrankC

My Wyred4Sound STP-SE has a a pretty nice implementation of this feature. It allows you to choose from any of the regular inputs to assign as the HT input, using a simple set-up procedure. While I have separate HT and stereo systems, this feature lets me use the preamp to switch from CD to phono input to drive a headphone amp directly from the source at line level. I have the headphone amp connected to an unused RCA output on the STP. You must also remember to turn the speaker amps off first!. I don't have to swap the input cables to the headphone amp.

Cary SLP-05 has a home theater bypass. It simply closes a switch that passes the bypass input to the outputs. Works whether preamp is on or off.

As Soix says, you can always make your own "home theater bypass" by attaching your receiver left/rights to any input and determining a standard volume setting of the pre that allows your receiver to be easily calibrated to have the left/right match the center volume. When you want to use "home theater bypass" just select that input and set the pre-amp volume control to the pre-determined place. Very easy if you have a digital volume display and still pretty easy even it it is a manual setting - just mark the appropriate volume.

Note this second method means the pre-amp is active in the case of home theater, whereas the Cary method takes the pre-amp circuitry out the picture. Either works.