Pani,
My experience is based ONLY on TVC and not other types of passives. But nevertheless, I would like to share.
Your amp's sensitivity is actually very low. The way people would look at the sensitivity would be - if it requires less volts for full power, then it is high sensitivity. If it requires more volts for full power, then it is low sensitivity. For a passive to work with an amp, the max sensitivity that you should go for an amp would be 1.5V for full power. The lower the better. My amp is 1V for full power,and I use a TVC. Or else, like Al mentioned, you will not hear the "full potential" of your system. Also Ralph has mentioned about speaker sensitivity - this also plays very important role in a "passive based" system. Ideally your speakers should be 90+db.
At this point, it looks like active pre would be the way for you, unless you change some components in your system.
My experience is based ONLY on TVC and not other types of passives. But nevertheless, I would like to share.
Your amp's sensitivity is actually very low. The way people would look at the sensitivity would be - if it requires less volts for full power, then it is high sensitivity. If it requires more volts for full power, then it is low sensitivity. For a passive to work with an amp, the max sensitivity that you should go for an amp would be 1.5V for full power. The lower the better. My amp is 1V for full power,and I use a TVC. Or else, like Al mentioned, you will not hear the "full potential" of your system. Also Ralph has mentioned about speaker sensitivity - this also plays very important role in a "passive based" system. Ideally your speakers should be 90+db.
At this point, it looks like active pre would be the way for you, unless you change some components in your system.