Preamp used in HT bypass - Signal degrade??

Is it a good idea to put a preamplifier between a Home Theater processor and your amplifiers?  Initially I thought it might be good to benefit from whatever the pre-amplifier may offer but if you got a very good processor it may be pointless and detrimental.

I tried it for a while and I think passing signal through a preamplifier tends to limit some detail.  It's like removing a restrictive conditioner from the power cord. Is this the case or am I imagining things? It may sound a lot clearer and open and including the preamplifier may not be a good thing.  So why does anybody use a bypass component it's just another piece of hardware along the signal chain?   Maybe it's a trade-off for the convenience.