what exactly is ht bypass

The subwoofer can be a problem, although there a several work around solutions.

The sub needs to stay at the reciever to remain active at it's present level.

You could move it to the new tube preamp...this does involve some amount of trade off...loss of (LFE's).

I would go into detail regarding any advantage/dis-advantage....but I'm not yet clear on your goals, and don't want to confuse you with info overload.

In my system...which is setup for several playback options (audiophile, and non-audiophile), I do the easy way out....run more than one sub.

Dave

i dont know if this clears up the sub issue..but..i just re read the manual..it has the option for 2 inputs specifically for this scenario..it can be run into the l/r input for pre..and the lfe for surround...dont know if all subs have that..but it was a nice surprise...will that solve the sub problem

Yes, If you can switch between those two inputs...or the sub will do the switching for you.

Just make sure that the manual states that you can use both inputs at the same time...and not, one or the other.

Dave

thanx for the input guys...i am clear now..i may post again when the pre arrives...till then..cheers and happy listening

"HT Bypass" = bypassing your home theater! - lol

No, actually, the bypass means bypassing your preamp functions for those channels that are output for HT dubties!
What happens is that your volume, tone controls, etc are bypassed in that input when you select it! Any signal being sent to that input goes directly through to your ampilfier, without any pre-amplification from pre/pro. Basically, you run your L/R main speaker outputs from your AV pre/pro or receiver to that input, when you want to add a multi-channel HT system, looping through your 2 channel pre. It's rather simple really.
It allows you to keep your 2 channel system setup as normal. And when you want to run your multi-channel ht processor, you can simply use the 2 channel amp setup you are already using for your L/R channels, without having to disconnect the 2 channel setup - because you still need the l/R channels from your 5 or 7 channel av processor, and your just simply using the mains and amp set up you have going to 2 channel pre and dubties, for your main l/r's of your theater! It's just a convenience feature, that's all.
If your 2 channel preamp didn't have this (actually Auxilary does the same, as would "tape-in"), you would likely have to disconnect the 2 channel preamp from your 2 channel amp, and reconnect it to your AV pre/pro when you payed movies - which is assuming you still are trying to use your stereo speakers as part of the HT system.