Tube preamps with HT bypass


Anyone know if any models that can engage the HT bypass with the power off or at least without the tubes burning?  Thought I read about one or two a loooong time ago that were able to do this.  Thanks!
soix
The Rogue RP7 (I own one) does HT bypass when powered off.  It's very handy in my system.  I have my Yamaha RX860 driving my power amp directly via this RP7 HT bypass for movies.
I know that the Backert Labs preamps have a HT Bypass that works with the preamp turned off.
I believe my VAC Renaissance Mk3 cinema pass through worked when the unit was not powered on.