. I did try a passive preamp in the main system recently and did Not like how it made the system sound
Not knowing the passive and what is was driving, including cables I would say this:
I have no problems with passives. If one thinks of it as the volume control on an integrated that is somewhat separated physically the question becomes: What is in the way? What might be loading the passive? Generally the problem is cable capacitance or output/input impedance problems (I wont say mismatch).
Heres the way I look at it. In an RM-10 the input is right to the grid of the tube. In a preamp its the same thing. Why should it sound any different?
People do like preamps for other reasons, many of which may be imaginary. I made lots of preamps. Of course you need one for phono.
Bill Johnson told me they sell twice as many preamps as power amps. Seems people like to play with preamps more. Some say because its the thing you touch.
In my system i got tired of the cables from the pre to the crossover. I wanted something really simple.
Because the RM-3 crossover has two knobs for high and low output I decided I needed only one, the bass and so made the treb pot into a volume control. Reduces cables and connector problems.
Now I think the way to make a crossover is with several line inputs, volume and bass level. So simple. I adjust the volume and sub level (100 Hz and down) on most every CD.
If you care to share the specs on the passive, cables and power amp we might figure out what was happening?