Hi Matthew, I don't think this approach will sound better. You would basically be using two pre-amps, the external one and the one built in in your receiver. An input on a pre-amp is designed to take a certain kind of input, let's say 500 mV. It will amplify this to a higher level which is enough to drive a poweramp. What you are doing is amplifying a signal so it's enough to feed a poweramp, and then amplify it again. Not only useless, but you might be overloading the input on the second preamp, which will cause distortion.
However - some integrated amps, or even receivers, have preamp-outputs and poweramp-inputs. This means you can use another preamp feeding the poweramp, or vice versa. I don't know the H/K, so I don't know whether it can be used that way. That might improve the sound a bit, provided the preamp you're using is of better quality then the one built in the H/K.
As for a combination of tubes and ss - I'm using that, a simple tube preamp and a monster Class A poweramp, and I love the sound. But that's no guarantee for succes, I'm sure there are plenty of combinations of tubes and ss that will sound awful. So - listen, and trust your ears.
However - some integrated amps, or even receivers, have preamp-outputs and poweramp-inputs. This means you can use another preamp feeding the poweramp, or vice versa. I don't know the H/K, so I don't know whether it can be used that way. That might improve the sound a bit, provided the preamp you're using is of better quality then the one built in the H/K.
As for a combination of tubes and ss - I'm using that, a simple tube preamp and a monster Class A poweramp, and I love the sound. But that's no guarantee for succes, I'm sure there are plenty of combinations of tubes and ss that will sound awful. So - listen, and trust your ears.