how good is the Krell HTS 7.1 pre-amp for 2ch?

Hughp3,

To get access to the jumper, you need to remove the cover. There is a small jumper on a small circuit board near the input connectors. Remove the jumper and the capacitor will be in the circuit to prevent dc voltage from getting into the amp.

As for the Audio Research Ref 5 preamp, it will work very well with Krell amps. I had the Ref 5se connected to a Krell 450 MCX and it sounded really good. You won't be going back to the HTS 7.1 for 2 channels once you hear the Ref 5

Update: purchased a pre-owned AR Ref5. Back to back comparison to the Krell HTS 7.1. Took some listening. The Wilson WP7 have had a hard, bright, edge to the high range. Ref 5 removed that edge. Some music was fatiguing and I could not put my finger on why. the highs now are humm buttery maybe, more musical, more organic less harsh. in any event the sound has improved although back to back was required. Bass however was a very pleasant surprise. The krell was muddy (dare I say that about krell) as compared. the Ref 5 brought a lot more punch and very good low hertz definition. Some tracks on Stanley Clark Bass Days no longer have a muddy thump but now have a very discernible pluck of the bass , not there before. Is the Ref5 a huge change, no, is it worth the dollar upgrade, to me yes ( my wife, no). However I can now listen without the fatigue and that makes it worth the investment to me. I agree with the previous post, a bought a 20 % improvement .

What about using two stereo pre-amplifier? I like ARC, what pre-amplifier, if one liked the surround effect of SACD, would it work to use ? I do not see the need for the centre channel and the LFE, I wonder, If I have the same as two pair of B&W 802 bass speakers in a bass tower, why would I need more bass? I also think it strange, related to music, to have speakers behind the listener; as when does a symphony play half its ensemble behind the audience? Why not place the surround closer, but further out and just a bit forward of the listener?