Are Their any Tube Preamp with Home Theater Bypass?

@kota1 I don’t know a lot about the MB50, but I probably wouldn’t consider it a true preamp, although it does have limited digital and analog inputs. I’m not sure it would be any sonic improvement over your Marantz in 2-channel direct mode.

McIntosh C12000, C2700 and C8 all have HT pass thru. I own the C2700 and use the HT pass thru with my Anthem surround processor.

Yes, it is true that the tubes in a preamp will be “consumed” even when using HT bypass. Just keep in mind signal tubes in a tube preamp last longer than power tubes in a tube amp. 12AX7’s, for example, can last upwards of 10,000 hours. I’m about 75% 2-channel music, 25% multi-channel HT, so not a huge concern for me. If you’re the reverse, it might be more of a concern, but not nearly as much with a tube preamp as if you were looking at a tube amp with a bunch of KT88’s that you were going to be running 8 hours a day between music and HT. It was for that very reason that I went with a tube preamp and solid state power amp.